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Diffstat (limited to 'day2')
| -rwxr-xr-x | day2/EngPython.tex | 1987 | ||||
| -rwxr-xr-x | day2/PythonMachinery.tex | 325 | ||||
| -rw-r--r-- | day2/session1.tex | 832 | ||||
| -rw-r--r-- | day2/session2.tex | 431 | ||||
| -rw-r--r-- | day2/session3.tex | 498 | ||||
| -rw-r--r-- | day2/tda.tex | 300 |
6 files changed, 0 insertions, 4373 deletions
diff --git a/day2/EngPython.tex b/day2/EngPython.tex deleted file mode 100755 index b8cfbd2..0000000 --- a/day2/EngPython.tex +++ /dev/null @@ -1,1987 +0,0 @@ -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% Tutorial slides on Python. -% -% Author: Prabhu Ramachandran <prabhu at aero.iitb.ac.in> -% Copyright (c) 2005-2008, Prabhu Ramachandran -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -\documentclass[14pt,compress]{beamer} -%\documentclass[draft]{beamer} -%\documentclass[compress,handout]{beamer} -%\usepackage{pgfpages} -%\pgfpagesuselayout{2 on 1}[a4paper,border shrink=5mm] - -% Modified from: generic-ornate-15min-45min.de.tex -\mode<presentation> -{ - \usetheme{Warsaw} - \useoutertheme{split} - \setbeamercovered{transparent} -} - -\usepackage[english]{babel} -\usepackage[latin1]{inputenc} -%\usepackage{times} -\usepackage[T1]{fontenc} - -% Taken from Fernando's slides. -\usepackage{ae,aecompl} -\usepackage{mathpazo,courier,euler} -\usepackage[scaled=.95]{helvet} - -\definecolor{darkgreen}{rgb}{0,0.5,0} - -\usepackage{listings} -\lstset{language=Python, - basicstyle=\ttfamily\bfseries, - commentstyle=\color{red}\itshape, - stringstyle=\color{darkgreen}, - showstringspaces=false, - keywordstyle=\color{blue}\bfseries} - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% Macros -\setbeamercolor{emphbar}{bg=blue!20, fg=black} -\newcommand{\emphbar}[1] -{\begin{beamercolorbox}[rounded=true]{emphbar} - {#1} - \end{beamercolorbox} -} -\newcounter{time} -\setcounter{time}{0} -\newcommand{\inctime}[1]{\addtocounter{time}{#1}{\tiny \thetime\ m}} - -\newcommand{\typ}[1]{\texttt{#1}} - -\newcommand{\kwrd}[1]{ \texttt{\textbf{\color{blue}{#1}}} } - -%%% This is from Fernando's setup. -% \usepackage{color} -% \definecolor{orange}{cmyk}{0,0.4,0.8,0.2} -% % Use and configure listings package for nicely formatted code -% \usepackage{listings} -% \lstset{ -% language=Python, -% basicstyle=\small\ttfamily, -% commentstyle=\ttfamily\color{blue}, -% stringstyle=\ttfamily\color{orange}, -% showstringspaces=false, -% breaklines=true, -% postbreak = \space\dots -% } - - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% Title page -\title[Basic Python]{Python,\\a great programming toolkit:\\ -numerics and plotting} - -\author[Asokan \& Prabhu] {Asokan Pichai\\Prabhu Ramachandran} - -\institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay} -\date[] {26, July 2009} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%\pgfdeclareimage[height=0.75cm]{iitmlogo}{iitmlogo} -%\logo{\pgfuseimage{iitmlogo}} - - -%% Delete this, if you do not want the table of contents to pop up at -%% the beginning of each subsection: -\AtBeginSubsection[] -{ - \begin{frame}<beamer> - \frametitle{Outline} - \tableofcontents[currentsection,currentsubsection] - \end{frame} -} - -\AtBeginSection[] -{ - \begin{frame}<beamer> - \frametitle{Outline} - \tableofcontents[currentsection,currentsubsection] - \end{frame} -} - -% If you wish to uncover everything in a step-wise fashion, uncomment -% the following command: -%\beamerdefaultoverlayspecification{<+->} - -%\includeonlyframes{current,current1,current2,current3,current4,current5,current6} - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% DOCUMENT STARTS -\begin{document} - -\begin{frame} - \titlepage -\end{frame} -\begin{frame} - {Acknowledgements} - \begin{center} - This program is conducted by\\ - IIT, Bombay\\ - through CDEEP\\ - as part of the open source initiatives\\ - under the aegis of\\ - \alert{National Mission on Education through ICT,} \\ - Ministry of HRD. - \end{center} -\end{frame} - -\begin{frame} - \frametitle{Outline} - \tableofcontents - % You might wish to add the option [pausesections] -\end{frame} - -\begin{frame}{Goal of the Workshop} - - At the end of this program, successful participants will be able - to use python as their scripting and problem solving language. - Aimed at Engg. students--focus on basic numerics and plotting-- - but should serve a similar purpose for others.\\ - - At the minimum you will be able to use Python for your plotting immediately. - -\end{frame} - -\begin{frame}{Checklist} - - \begin{description} - \item[pylab] matplotlib interface - \item[numpy] Array computing - \item[scipy] numerical work - \item[mayavi] \typ{enthought.mayavi}: 3D viz. - \end{description} -\end{frame} - -\section{30000 feet view} -\begin{frame}{Lets see what we can do!} - \huge - Hold on to your seatbelts -\end{frame} - -\begin{frame} - {That was done by\ldots} - \begin{description}[CalisthenicsIsAnArt] - \item[Arrays] 2--3 lines; 5 minutes to learn - \item[2D plots] 5 lines; 10 minutes to learn - \item[Simple 3D plots] 5 lines; 10 minutes to learn; GUI - exploration! - \item[Complex plots] relatively short (10-15 lines); more time to master; - \end{description} - \inctime{15} -\end{frame} - -\section{Matplotlib} - -\subsection{Basic \typ{numpy} } - -\newcommand{\num}{\texttt{numpy}} - -\begin{frame} - \frametitle{The \num\ module} - \begin{itemize} - \item Why? - \item What: - \begin{itemize} - \item An efficient and powerful array type for various common data - types - \item Abstracts out the most commonly used standard operations on - arrays - \end{itemize} - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Examples of \num} -\begin{lstlisting} -# Simple array math example ->>> from numpy import * ->>> a = array([1,2,3,4]) ->>> b = array([2,3,4,5]) ->>> a*2 + b + 1 # Basic math! -array([5, 8, 11, 14]) -# Pi and e are defined. ->>> x = linspace(0.0, 10.0, 1000) ->>> x *= 2*pi/10 # inplace. -# apply functions to array. ->>> y = sin(x) -\end{lstlisting} -\end{frame} - -\begin{frame} - \frametitle{Basic concepts} - \begin{itemize} - \item fixed size (\typ{arr.size}); - \item Same type (\typ{arr.dtype}) of data - \item arbitrary dimensionality - \item \typ{arr.shape}: size in each dimension - \item \alert{Note:} \typ{len(arr) != arr.size} in general - \item \alert{Note:} By default array operations are performed - \alert{elementwise} - \item Indices, slicing: just like lists - \end{itemize} -\end{frame} - - -\begin{frame}[fragile] - \frametitle{More examples of \num} -\vspace*{-8pt} -\begin{lstlisting} ->>> x = array([1., 2, 3, 4]) ->>> size(x) -4 ->>> x.dtype # What is a.dtype? -dtype('float64') ->>> x.shape -(4,) ->>> print rank(x), x.itemsize -1 8 ->>> x[0] = 10 ->>> print x[0], x[-1] -10.0 4.0 -\end{lstlisting} - -\inctime{10} -\end{frame} - - - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\subsection{Plotting with \typ{pylab}} - -\begin{frame} - {IPython's \typ{pylab} mode} -\begin{itemize} - \item \typ{pylab}: convenient 2D plotting interface to MPL - \item Immediate use: \typ{ipython -pylab} - \item Imports all of pylab for you! - \item Allows for interactive plotting -\end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Basic 2D plotting} - -\begin{lstlisting} ->>> x = linspace(0, 2*pi, 1000) ->>> plot(x, sin(x)) ->>> plot(x, sin(x), 'ro') ->>> xlabel(r'$\chi$', color='g') -# LaTeX markup! ->>> ylabel(r'sin($\chi$)', color='r') ->>> title('Simple figure', fontsize=20) ->>> savefig('/tmp/test.eps') -\end{lstlisting} -\begin{itemize} - \item Also: PNG, PDF, PS, EPS, SVG, PDF -\end{itemize} -\end{frame} - - -\begin{frame}[fragile] - \frametitle{Basic plotting \ldots} -\begin{lstlisting} -# Set properties of objects: ->>> l, = plot(x, sin(x)) -# Why "l,"? ->>> setp(l, linewidth=2.0, color='r') ->>> l.set_linewidth(2.0) ->>> draw() # Redraw. ->>> setp(l) # Print properties ->>> clf() # Clear figure. ->>> close() # Close figure. -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Multiple figures} - -\begin{lstlisting} ->>> figure(1) ->>> plot(x, sin(x)) ->>> figure(2) ->>> plot(x, tanh(x)) ->>> figure(1) ->>> title('Easy as 1,2,3') -\end{lstlisting} - -\end{frame} - - -\begin{frame}[fragile] - \frametitle{Legends and Annotation} -\begin{lstlisting} ->>> plot(x, cos(5*x), 'r--', - label='cosine') ->>> plot(x, sin(5*x), 'g--', - label='sine') ->>> legend() -# Or use: ->>> legend(['cosine', 'sine']) -# Annotation: ->>> text(1,0, '(1,0)') -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{More commands \ldots} - \begin{lstlisting} -# semilog, loglog ->>> x = 10.**(-arange(100)*0.1) ->>> semilogx(x, x) ->>> semilogy(x, x) ->>> loglog(x, x) ->>> loglog(x, x*x) - \end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{More plots \ldots} - \begin{lstlisting} ->>> clf() ->>> t = arange(0.1, 4, 0.1) ->>> s = exp(-t) ->>> e = 0.1*abs(randn(len(s))) ->>> errorbar(t, s, e) -# Scatter plots ->>> clf() ->>> t = randn(len(e)) ->>> scatter(t, e, c=s) - \end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Note: \typ{pylab} in Python scripts} -\begin{lstlisting} -import pylab -x = pylab.linspace(0, 20, 1000) -pylab.plot(x, pylab.sin(x)) - -# Can also use: -from pylab import linspace, sin, plot -\end{lstlisting} -\end{frame} - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -\begin{frame}[fragile] - \frametitle{X-Y plot} - \begin{columns} - \column{0.5\textwidth} - \hspace*{-0.5in} - \includegraphics[height=2in, interpolate=true]{data/xyplot} - \column{0.45\textwidth} - \begin{block}{Example code} - \tiny -\begin{lstlisting} -t1 = arange(0.0, 5.0, 0.1) -t2 = arange(0.0, 5.0, 0.02) -t3 = arange(0.0, 2.0, 0.01) -subplot(211) -plot(t1, cos(2*pi*t1)*exp(-t1), 'bo', - t2, cos(2*pi*t2)*exp(-t2), 'k') -grid(True) -title('A tale of 2 subplots') -ylabel('Damped') -subplot(212) -plot(t3, cos(2*pi*t3), 'r--') -grid(True) -xlabel('time (s)') -ylabel('Undamped') -\end{lstlisting} - \end{block} - \end{columns} -\end{frame} - -\begin{frame}[fragile] \frametitle{Semi-log and log-log plots} - \begin{columns} - \column{0.5\textwidth} - \hspace*{-0.5in} - \includegraphics[height=2in, interpolate=true]{data/log} - \column{0.45\textwidth} - \begin{block}{Example code} - \tiny -\begin{lstlisting} -dt = 0.01 -t = arange(dt, 20.0, dt) -subplot(311) -semilogy(t, exp(-t/5.0)) -ylabel('semilogy') -grid(True) -subplot(312) -semilogx(t, sin(2*pi*t)) -ylabel('semilogx') -grid(True) -# minor grid on too -gca().xaxis.grid(True, which='minor') -subplot(313) -loglog(t, 20*exp(-t/10.0), basex=4) -grid(True) -ylabel('loglog base 4 on x') -\end{lstlisting} - \end{block} -\end{columns} -\end{frame} - -\begin{frame}[fragile] \frametitle{Errorbar} - \begin{columns} - \column{0.5\textwidth} - \hspace*{-0.5in} - \includegraphics[height=2in, interpolate=true]{data/errorbar} - \column{0.45\textwidth} - \begin{block}{Example code} - \tiny -\begin{lstlisting} -t = arange(0.1, 4, 0.1) -s = exp(-t) -e = 0.1*abs(randn(len(s))) -f = 0.1*abs(randn(len(s))) -g = 2*e -h = 2*f -errorbar(t, s, [e,g], f, fmt='o') -xlabel('Distance (m)') -ylabel('Height (m)') -title('Mean and standard error '\ - 'as a function of distance') -\end{lstlisting} - \end{block} -\end{columns} -\end{frame} - -\begin{frame}[fragile] \frametitle{Histogram} - \begin{columns} - \column{0.5\textwidth} - \hspace*{-0.5in} - \includegraphics[height=2in, interpolate=true]{data/histogram} - \column{0.45\textwidth} - \begin{block}{Example code} - \tiny -\begin{lstlisting} -mu, sigma = 100, 15 -x = mu + sigma*randn(10000) -# the histogram of the data -n, bins, patches = hist(x, 100, normed=1) -# add a 'best fit' line -y = normpdf( bins, mu, sigma) -l = plot(bins, y, 'r--', linewidth=2) -xlim(40, 160) -xlabel('Smarts') -ylabel('P') -title(r'$\rm{IQ:}\/ \mu=100,\/ \sigma=15$') -\end{lstlisting} - \end{block} -\end{columns} -\end{frame} - -\begin{frame}[fragile] \frametitle{Bar charts} - \begin{columns} - \column{0.5\textwidth} - \hspace*{-0.5in} - \includegraphics[height=2in, interpolate=true]{data/barchart} - \column{0.45\textwidth} - \begin{block}{Example code} - \tiny -\begin{lstlisting} -N = 5 -menMeans = (20, 35, 30, 35, 27) -menStd = ( 2, 3, 4, 1, 2) -# the x locations for the groups -ind = arange(N) -# the width of the bars -width = 0.35 -p1 = bar(ind, menMeans, width, - color='r', yerr=menStd) -womenMeans = (25, 32, 34, 20, 25) -womenStd = ( 3, 5, 2, 3, 3) -p2 = bar(ind+width, womenMeans, width, - color='y', yerr=womenStd) -ylabel('Scores') -title('Scores by group and gender') -xticks(ind+width, - ('G1', 'G2', 'G3', 'G4', 'G5')) -xlim(-width,len(ind)) -yticks(arange(0,41,10)) -legend((p1[0], p2[0]), - ('Men', 'Women'), shadow=True) -\end{lstlisting} - \end{block} -\end{columns} -\end{frame} - -\begin{frame}[fragile] \frametitle{Pie charts} - \begin{columns} - \column{0.5\textwidth} - \hspace*{-0.4in} - \includegraphics[height=2.0in, interpolate=true]{data/piechart} - \column{0.45\textwidth} - \begin{block}{Example code} - \tiny -\begin{lstlisting} -# make a square figure and axes -figure(1, figsize=(8,8)) -ax = axes([0.1, 0.1, 0.8, 0.8]) -labels = 'Frogs', 'Hogs', 'Dogs', 'Logs' -fracs = [15,30,45, 10] -explode=(0, 0.05, 0, 0) -pie(fracs, explode=explode, labels=labels, - autopct='%1.1f%%', shadow=True) -title('Raining Hogs and Dogs', - bbox={'facecolor':'0.8', 'pad':5}) -\end{lstlisting} - \end{block} -\end{columns} -\end{frame} - -\begin{frame}[fragile] \frametitle{Scatter plots} - \begin{columns} - \column{0.5\textwidth} - \hspace*{-0.4in} - \includegraphics[height=2in, interpolate=true]{data/scatter} - \column{0.45\textwidth} - \begin{block}{Example code} - \tiny -\begin{lstlisting} -N = 30 -x = 0.9*rand(N) -y = 0.9*rand(N) -# 0 to 10 point radiuses -area = pi*(10 * rand(N))**2 -volume = 400 + rand(N)*450 -scatter(x,y,s=area, marker='o', c=volume, - alpha=0.75) -xlabel(r'$\Delta_i$', size='x-large') -ylabel(r'$\Delta_{i+1}$', size='x-large') -title(r'Volume and percent change') -grid(True) -colorbar() -savefig('scatter') -\end{lstlisting} - \end{block} -\end{columns} -\end{frame} - -\begin{frame}[fragile] \frametitle{Polar} - \begin{columns} - \column{0.5\textwidth} - \hspace*{-0.5in} - \includegraphics[height=2in, interpolate=true]{data/polar} - \column{0.45\textwidth} - \begin{block}{Example code} - \tiny -\begin{lstlisting} -figure(figsize=(8,8)) -ax = axes([0.1, 0.1, 0.8, 0.8], - polar=True, - axisbg='#d5de9c') -r = arange(0,1,0.001) -theta = 2*2*pi*r -polar(theta, r, color='#ee8d18', lw=3) -# the radius of the grid labels -setp(ax.thetagridlabels, y=1.075) -title(r"$\theta=4\pi r", fontsize=20) -\end{lstlisting} - \end{block} -\end{columns} -\end{frame} - -\begin{frame}[fragile] \frametitle{Contours} - \begin{columns} - \column{0.45\textwidth} - \hspace*{-0.5in} - \includegraphics[height=2in, interpolate=true]{data/contour} - \column{0.525\textwidth} - \begin{block}{Example code} - \tiny -\begin{lstlisting} -x = arange(-3.0, 3.0, 0.025) -y = arange(-2.0, 2.0, 0.025) -X, Y = meshgrid(x, y) -Z1 = bivariate_normal(X, Y, 1.0, 1.0, 0.0, 0.0) -Z2 = bivariate_normal(X, Y, 1.5, 0.5, 1, 1) -# difference of Gaussians -Z = 10.0 * (Z2 - Z1) -im = imshow(Z, interpolation='bilinear', - origin='lower', - cmap=cm.gray, extent=(-3,3,-2,2)) -levels = arange(-1.2, 1.6, 0.2) -# label every second level -clabel(CS, levels[1::2], inline=1, - fmt='%1.1f', fontsize=14) -CS = contour(Z, levels, - origin='lower', - linewidths=2, - extent=(-3,3,-2,2)) -# make a colorbar for the contour lines -CB = colorbar(CS, shrink=0.8, extend='both') -title('Lines with colorbar') -hot(); flag() -\end{lstlisting} - \end{block} -\end{columns} -\end{frame} - -\begin{frame}[fragile] \frametitle{Velocity vectors} - \begin{columns} - \column{0.5\textwidth} - \hspace*{-0.5in} - \includegraphics[height=2in, interpolate=true]{data/quiver} - \column{0.45\textwidth} - \begin{block}{Example code} - \tiny -\begin{lstlisting} -X,Y = meshgrid(arange(0,2*pi,.2), - arange(0,2*pi,.2) ) -U = cos(X) -V = sin(Y) -Q = quiver(X[::3, ::3], Y[::3, ::3], - U[::3, ::3], V[::3, ::3], - color='r', units='x', - linewidths=(2,), - edgecolors=('k'), - headaxislength=5 ) -qk = quiverkey(Q, 0.5, 0.03, 1, '1 m/s', - fontproperties= - {'weight': 'bold'}) -axis([-1, 7, -1, 7]) -title('triangular head; scale '\ - 'with x view; black edges') -\end{lstlisting} - \end{block} -\end{columns} -\end{frame} - -\begin{frame}[fragile] \frametitle{Maps} - \includegraphics[height=2.5in, interpolate=true]{data/plotmap} - \begin{center} - \tiny - For details see \url{http://matplotlib.sourceforge.net/screenshots/plotmap.py} - \end{center} -\end{frame} - - -\begin{frame} - \frametitle{More information} - \begin{itemize} - \item More information here: \url{http://matplotlib.sf.net} - \item \url{http://matplotlib.sf.net/tutorial.html} - \item \url{http://matplotlib.sf.net/screenshots.html} - \end{itemize} - - \inctime{25} -\end{frame} - -\begin{frame} - \frametitle{Problem set 1.0} - \begin{enumerate} - \item Write a function that plots any n-gon given \typ{n}. - \item Consider the logistic map, $f(x) = kx(1-x)$, plot it for - $k=2.5, 3.5$ and $4$ -\end{enumerate} -\end{frame} - -\begin{frame} - \frametitle{Problem set 1.1} - \begin{enumerate} - \item Consider the iteration $x_{n+1} = f(x_n)$ where $f(x) = - kx(1-x)$. Plot the successive iterates of this process. - \item Plot this using a cobweb plot as follows: - \begin{enumerate} - \item Start at $(x_0, 0)$ - \item Draw line to $(x_i, f(x_i))$; - \item Set $x_{i+1} = f(x_i)$ - \item Draw line to $(x_i, x_i)$ - \item Repeat from 2 for as long as you want - \end{enumerate} - \end{enumerate} -\end{frame} - -\begin{frame} - \frametitle{Problem set 1.2} - \begin{enumerate} - - \item Plot the Koch snowflake. Write a function to generate the - necessary points given the two points constituting a line. - \pause - \begin{enumerate} - \item Split the line into 4 segments. - \item The first and last segments are trivial. - \item To rotate the point you can use complex numbers, - recall that $z e^{j \theta}$ rotates a point $z$ in 2D - by $\theta$. - \item Do this for all line segments till everything is - done. - \end{enumerate} - \item Show rate of convergence for a first and second order finite - difference of sin(x) -\end{enumerate} -\inctime{30} -\end{frame} - - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -\begin{frame}[fragile] - \frametitle{More IPython features} - \begin{itemize} - \item Input and output caching: - \begin{itemize} - \item \verb+In+: a list of all entered input - \item \verb+Out+: a dict of all output - \item \verb+%hist [-n]+ macro shows previous history, \verb+-n+ - suppresses line number information - \end{itemize} - \item Log the session using \verb+%logstart+, \verb+%logon+ and - \verb+%logoff+ - \item Use \verb+;+ to suppress printing output - \item \verb+%time statement+ - \item \verb+%timeit [-n<N> -r<R> [-t|-c]] statement+ - - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{More IPython features} - \begin{itemize} - \item \verb+%run [options] file[.py]+ -- running Python code - \item \verb+%prun+ runs a statement/expression under the profiler - \item \verb+%debug+: Helps with debugging after a crash - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{More IPython features \ldots} - \begin{itemize} - \item \verb+%edit [options] [args]+: edit lines of code or file - specified in editor (configure editor via \verb+$EDITOR+) - \item \verb+%cd+ changes directory, see also \verb+%pushd, %popd, %dhist+ - \item Shell access - \begin{itemize} - \item \verb+!command+ runs a shell command and returns its output - \item \verb+files = !ls+ sets - \verb+files+ to all result of the \verb+ls+ command - \item \verb+!ls $files+ passes the \verb+files+ variable to the - shell command - \end{itemize} - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{More IPython features \ldots} - \begin{itemize} - \item \verb+%bookmark+: store a bookmarked location, for use with \verb+%cd+ - \item \verb+%save [options] filename n1-n2 n3-n4+: save lines to a - file - \item Can define and use profiles to setup IPython differently: - \verb+math, scipy, numeric, pysh+ etc. - \item \verb+%magic+: \alert{Show help on all magics} - \item Check out the \verb+%macro+ magic - \end{itemize} -\end{frame} - -\begin{frame} - \frametitle{Problem set 2} - \begin{itemize} - \item Compare your linspace with that of numpy for 1 million - elements in terms of speed. -\end{itemize} -\inctime{10} -\end{frame} - - -\begin{frame}[fragile] - \frametitle{Debugging effectively} - - \begin{itemize} - \item \kwrd{print} based strategy - \item Process: Hypothesis, test, refine, rinse-repeat - \item Using \typ{\%debug} and \typ{\%pdb} in IPython - \end{itemize} - - \inctime{10} -\end{frame} - -\section{Debugging and testing} - -\begin{frame}[fragile] - \frametitle{Testing code with \typ{nosetests}} - - \begin{itemize} - \item Writing tests is really simple! - - \item Using nose - - \item Example! - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Nosetest} -\begin{lstlisting} -def gcd(a, b): - """Returns gcd of a and b, - handles only positive numbers.""" - if a%b == 0: return b - return gcd(b, a%b) -def lcm(a, b): - return a*b/gcd(a, b) - -if __name__ == '__main__': - import nose - nose.main() -\end{lstlisting} - - \inctime{10} -\end{frame} - -\section{NumPy and SciPy} - -\begin{frame} - {More Numpy} - - \begin{itemize} - \item Multi-dimensional arrays - \item Random number generation - \end{itemize} - -\end{frame} - -\begin{frame}[fragile] - \frametitle{Multi-dimensional arrays} -\begin{lstlisting} ->>> a = array([[ 0, 1, 2, 3], -... [10,11,12,13]]) ->>> a.shape # (rows, columns) -(2, 4) -# Accessing and setting values ->>> a[1,3] -13 ->>> a[1,3] = -1 ->>> a[1] # The second row -array([10,11,12,-1]) - -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Slicing arrays} -\begin{lstlisting} ->>> a = array([[1,2,3], [4,5,6], - [7,8,9]]) ->>> a[0,1:3] -array([2, 3]) ->>> a[1:,1:] -array([[5, 6], - [8, 9]]) ->>> a[:,2] -array([3, 6, 9]) -\end{lstlisting} -\end{frame} -\begin{frame}[fragile] - \frametitle{Striding arrays} -\begin{lstlisting} ->>> a[0::2,0::2] -array([[1, 3], - [7, 9]]) -# Slices are references to the -# same memory! -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Array creation functions} - \begin{itemize} - \item \typ{array(object, dtype=None, \ldots)} - \item \typ{arange(start, stop=None, step=1 \ldots)} - \item \typ{linspace(start, stop, num=50, \ldots)} - \item \typ{ones(shape, dtype=None, \ldots)} - \item \typ{zeros(shape, dtype=float,\ldots)} - \item \typ{identity(n)} - \item \typ{empty(shape, dtype=float,\ldots)} - \item \typ{ones\_like(x)}, - \item \typ{zeros\_like(x)}, \typ{empty\_like(x)} - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Array math} - \begin{itemize} - \item Basic \alert{elementwise} math (given two arrays \typ{a, b}): - \typ{+, -, *, /, \%} - \item Inplace operators: \typ{a += b}, or \typ{add(a, b, - a)} etc. - \item Logical operations: \typ{equal (==)}, \typ{not\_equal (!=)}, - \typ{less (<)}, \typ{greater (>)} etc. - \item Trig and other functions: \typ{sin(x), arcsin(x), sinh(x), - exp(x), sqrt(x)} etc. - \item \typ{sum(x, axis=0), product(x, axis=0)} - \item \typ{dot(a, b)} - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Advanced} - \begin{itemize} - \item Only scratched the surface of \num - \item Ufunc methods: \typ{reduce, accumulate, outer, reduceat} - \item Typecasting - \item More functions: \typ{take, choose, where, compress, - concatenate} - \item Array broadcasting and \typ{None} - \end{itemize} - \inctime{15} -\end{frame} - -\begin{frame} - {Intro to SciPy} - \begin{itemize} - \item \url{http://www.scipy.org} - \item Open source scientific libraries for Python - \item Based on NumPy - \end{itemize} - - \inctime{25} -\end{frame} - -\begin{frame} - \frametitle{SciPy} - \begin{itemize} - \item Provides: - \begin{itemize} - \item Linear algebra - \item Numerical integration - \item Fourier transforms - \item Signal processing - \item Special functions - \item Statistics - \item Optimization - \item Image processing - \item ODE solvers - \end{itemize} - \item Uses LAPACK, QUADPACK, ODEPACK, FFTPACK etc. from netlib - \end{itemize} -\end{frame} - - -\section{3D Plotting} - -\begin{frame} - \frametitle{Introduction to Mayavi} - \begin{itemize} - \item Most scientists not interested in details of visualization - \item Visualization of data files with a nice UI - \item Interactive visualization of data (think Matlab) - \item Embedding visualizations in applications - \item Customization - \end{itemize} - \pause - \begin{block}{The Goal} - Provide a \alert{flexible} library/app for every one of these needs! - \end{block} -\end{frame} - -\begin{frame}[fragile] - \frametitle{\typ{mlab}} - \begin{columns} - \column{0.62\textwidth} - \hspace*{-0.45in} - \footnotesize -\begin{lstlisting} -from enthought.mayavi import mlab -from numpy import ogrid, sin - -x, y, z = ogrid[-10:10:100j, - -10:10:100j, - -10:10:100j] - -mlab.contour3d(sin(x*y*z)/(x*y*z)) -mlab.show() -\end{lstlisting} - \column{0.4\textwidth} - \hspace*{-0.1\linewidth} - \includegraphics[width=1.18\linewidth]{data/mlab.png} - \end{columns} -\end{frame} - -\begin{frame} - {A Look at the docs } - - \inctime{20} -\end{frame} - - -\section{Integration demo: Lorenz equations} - -\begin{frame} - \frametitle{Lorenz equation example} - \begin{eqnarray*} - \frac{d x}{dt} &=& s (y-x)\\ - \frac{d y}{d t} &=& rx -y -xz\\ - \frac{d z}{d t} &=& xy - bz\\ - \end{eqnarray*} - \begin{itemize} - \item Specifies the evolution of the system - \item Think: Velocity of a particle in 3D - \item Lets trace its path - \end{itemize} -\end{frame} - -\begin{frame} - {Interactive exploration} - - \inctime{25} -\end{frame} - - -\end{document} - -- Numpy arrays (30 mins) - - Matrices - - random number generation. - - Image manipulation: jigsaw puzzle. - - Monte-carlo integration. - - - - - -\begin{frame}[fragile] - \frametitle{More on functions} - \begin{itemize} - \item Support default and keyword arguments - \item Scope of variables in the function is local - \item Mutable items are \alert{passed by reference} - \item First line after definition may be a documentation string - (\alert{recommended!}) - \item Function definition and execution defines a name bound to the - function - \item You \emph{can} assign a variable to a function! - \end{itemize} -\end{frame} - - -\begin{frame}[fragile] - \frametitle{Functions: default arguments} - \begin{lstlisting} -def ask_ok(prompt, retries=4, complaint='Yes or no!'): - while True: - ok = raw_input(prompt) - if ok in ('y', 'ye', 'yes'): - return True - if ok in ('n', 'no', 'nop', 'nope'): - return False - retries = retries - 1 - if retries < 0: - raise IOError, 'bad user' - print complaint - \end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Functions: keyword arguments} - \begin{lstlisting} -def parrot(voltage, state='a stiff', - action='voom', type='Norwegian Blue'): - print "-- This parrot wouldn't", action, - print "if you put", voltage, "Volts through it." - print "-- Lovely plumage, the", type - print "-- It's", state, "!" - -parrot(1000) -parrot(action = 'VOOOOOM', voltage = 1000000) -parrot('a thousand', state = 'pushing up the daisies') -parrot('a million', 'bereft of life', 'jump') -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Functions: arbitrary argument lists} - \begin{itemize} - \item Arbitrary number of arguments using \verb+*args+ or - \verb+*whatever+ - \item Keyword arguments using \verb+**kw+ - \item Given a tuple/dict how do you call a function? - \begin{itemize} - \item Using argument unpacking - \item For positional arguments: \verb+foo(*[5, 10])+ - \item For keyword args: \verb+foo(**{'a':5, 'b':10})+ - \end{itemize} - \end{itemize} -\begin{lstlisting} -def foo(a=10, b=100): - print a, b -def func(*args, **keyword): - print args, keyword -# Unpacking: -args = [5, 10] -foo(*args) -kw = {'a':5, 'b':10} -foo(**kw) -\end{lstlisting} -\end{frame} - -\subsection{Modules, exceptions, classes} - -\begin{frame} - \frametitle{Modules} - \begin{itemize} - \item Define variables, functions and classes in a file with a - \typ{.py} extension - \item This file becomes a module! - \item Modules are searched in the following: - \begin{itemize} - \item Current directory - \item Standard: \typ{/usr/lib/python2.3/site-packages/} etc. - \item Directories specified in PYTHONPATH - \item \typ{sys.path}: current path settings (from the \typ{sys} - module) - \end{itemize} - \item The \typ{import} keyword ``loads'' a module - \item One can also use: - \mbox{\typ{from module import name1, name2, name2}}\\ - where \typ{name1} etc. are names in the module, ``module'' - \item \typ{from module import *} \ --- imports everything from module, - \alert{use only in interactive mode} - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Modules: example} - \begin{lstlisting} -# --- foo.py --- -some_var = 1 -def fib(n): # write Fibonacci series up to n - """Print a Fibonacci series up to n.""" - a, b = 0, 1 - while b < n: - print b, - a, b = b, a+b -# EOF - ->>> import foo ->>> foo.fib(10) -1 1 2 3 5 8 ->>> foo.some_var -1 - \end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Namespaces} - \begin{itemize} - \item A mapping from names to objects - \item Modules introduce a namespace - \item So do classes - \item The running script's namespace is \verb+__main__+ - \item A modules namespace is identified by its name - \item The standard functions (like \typ{len}) are in the - \verb+__builtin__+ namespace - \item Namespaces help organize different names and their bindings to - different objects - \end{itemize} -\end{frame} - -\begin{frame} - \frametitle{Exceptions} - \begin{itemize} - \item Python's way of notifying you of errors - \item Several standard exceptions: \typ{SyntaxError}, \typ{IOError} - etc. - \item Users can also \typ{raise} errors - \item Users can create their own exceptions - \item Exceptions can be ``caught'' via \typ{try/except} blocks - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Exception: examples} -\begin{lstlisting} ->>> 10 * (1/0) -Traceback (most recent call last): - File "<stdin>", line 1, in ? -ZeroDivisionError: integer division or modulo by zero ->>> 4 + spam*3 -Traceback (most recent call last): - File "<stdin>", line 1, in ? -NameError: name 'spam' is not defined ->>> '2' + 2 -Traceback (most recent call last): - File "<stdin>", line 1, in ? -TypeError: cannot concatenate 'str' and 'int' objects -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Exception: examples} -\begin{lstlisting} ->>> while True: -... try: -... x = int(raw_input("Enter a number: ")) -... break -... except ValueError: -... print "Invalid number, try again..." -... ->>> # To raise exceptions -... raise ValueError, "your error message" -Traceback (most recent call last): - File "<stdin>", line 2, in ? -ValueError: your error message -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Classes: the big picture} - \begin{itemize} - \item Lets you create new data types - \item Class is a template for an object belonging to that class - \item Note: in Python a class is also an object - \item Instantiating a class creates an instance (an object) - \item An instance encapsulates the state (data) and behavior - (methods) - \item Allows you to define an inheritance hierarchy - \begin{itemize} - \item ``A Honda car \alert{is a} car.'' - \item ``A car \alert{is an} automobile.'' - \item ``A Python \alert{is a} reptile.'' - \end{itemize} - \item Programmers need to think OO - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Classes: what's the big deal?} - \begin{itemize} - \item Lets you create objects that mimic a real problem being - simulated - \item Makes problem solving more natural and elegant - \item Easier to create code - \item Allows for code-reuse - \item Polymorphism - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Class definition and instantiation} - \begin{itemize} - \item Class definitions when executed create class objects - \item Instantiating the class object creates an instance of the - class - \end{itemize} -\footnotesize -\begin{lstlisting} -class Foo(object): - pass -# class object created. -# Create an instance of Foo. -f = Foo() -# Can assign an attribute to the instance -f.a = 100 -print f.a -100 -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Classes \ldots} - \begin{itemize} - \item All attributes are accessed via the \typ{object.attribute} - syntax - \item Both class and instance attributes are supported - \item \emph{Methods} represent the behavior of an object: crudely - think of them as functions ``belonging'' to the object - \item All methods in Python are ``virtual'' - \item Inheritance through subclassing - \item Multiple inheritance is supported - \item No special public and private attributes: only good - conventions - \begin{itemize} - \item \verb+object.public()+: public - \item \verb+object._private()+ \& \verb+object.__priv()+: - non-public - \end{itemize} - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Classes: examples} -\begin{lstlisting} -class MyClass(object): - """Example class (this is the class docstring).""" - i = 12345 # A class attribute - def f(self): - """This is the method docstring""" - return 'hello world' - ->>> a = MyClass() # creates an instance ->>> a.f() -'hello world' ->>> # a.f() is equivalent to MyClass.f(a) -... # This also explains why f has a 'self' argument. -... MyClass.f(a) -'hello world' -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Classes (continued)} - \begin{itemize} - \item \typ{self} is \alert{conventionally} the first argument for a - method - \item In previous example, \typ{a.f} is a method object - \item When \typ{a.f} is called, it is passed the instance \typ{a} as - the first argument - \item If a method called \verb+__init__+ exists, it is called when - the object is created - \item If a method called \verb+__del__+ exists, it is called before - the object is garbage collected - \item Instance attributes are set by simply ``setting'' them in - \typ{self} - \item Other special methods (by convention) like \verb+__add__+ let - you define numeric types: - {\footnotesize \url{http://docs.python.org/ref/specialnames.html} - \\ \url{http://docs.python.org/ref/numeric-types.html} - } - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Classes: examples} -\begin{lstlisting} -class Bag(MyClass): # Shows how to derive classes - def __init__(self): # called on object creation. - self.data = [] # an instance attribute - def add(self, x): - self.data.append(x) - def addtwice(self, x): - self.add(x) - self.add(x) ->>> a = Bag() ->>> a.f() # Inherited method -'hello world' ->>> a.add(1); a.addtwice(2) ->>> a.data -[1, 2, 2] -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Derived classes} - \begin{itemize} - \item Call the parent's \verb+__init__+ if needed - \item If you don't need a new constructor, no need to define it in subclass - \item Can also use the \verb+super+ built-in function - \end{itemize} -\begin{lstlisting} -class AnotherBag(Bag): - def __init__(self): - # Must call parent's __init__ explicitly - Bag.__init__(self) - # Alternatively use this: - super(AnotherBag, self).__init__() - # Now setup any more data. - self.more_data = [] -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Classes: polymorphism} -\begin{lstlisting} -class Drawable(object): - def draw(self): - # Just a specification. - pass -\end{lstlisting} -\mode<presentation>{\pause} -\begin{lstlisting} -class Square(Drawable): - def draw(self): - # draw a square. -class Circle(Drawable): - def draw(self): - # draw a circle. -\end{lstlisting} -\mode<presentation>{\pause} -\begin{lstlisting} -class Artist(Drawable): - def draw(self): - for obj in self.drawables: - obj.draw() -\end{lstlisting} -\end{frame} - -\subsection{Miscellaneous} - -\begin{frame}[fragile] - \frametitle{Stand-alone scripts} -Consider a file \typ{f.py}: -\begin{lstlisting} -#!/usr/bin/env python -"""Module level documentation.""" -# First line tells the shell that it should use Python -# to interpret the code in the file. -def f(): - print "f" - -# Check if we are running standalone or as module. -# When imported, __name__ will not be '__main__' -if __name__ == '__main__': - # This is not executed when f.py is imported. - f() -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{List comprehensions} -\begin{lstlisting} ->>> veg = ['tomato', 'cabbage', 'carrot', 'potato'] ->>> [x.upper() for x in veg] -['TOMATO', 'CABBAGE', 'CARROT', 'POTATO'] ->>> vec = range(0, 8) ->>> even = [x for x in vec if x%2 == 0] ->>> even -[0, 2, 4, 6] ->>> [x*x for x in even] -[0, 4, 16, 36] ->>> odd = [x for x in vec if x%2 == 1] ->>> odd -[1, 3, 5, 7] ->>> [x*y for x in even for y in odd] -[0, 0, 0, 0, 2, 6, 10, 14, 4, 12, 20, 28, 6, 18,30,42] -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{File handling} -\begin{lstlisting} ->>> # Reading files: -... f = open('/path/to/file_name') ->>> data = f.read() # Read entire file. ->>> line = f.readline() # Read one line. ->>> # Read entire file appending each line into a list -... lines = f.readlines() ->>> f.close() # close the file. ->>> # Writing files: -... f = open('/path/to/file_name', 'w') ->>> f.write('hello world\n') -\end{lstlisting} - \begin{itemize} - \item \typ{tell()}: returns int of current position - \item \typ{seek(pos)}: moves current position to specified byte - \item Call \typ{close()} when done using a file - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Math} - \begin{itemize} - \item \typ{math} module provides basic math routines for - floats - \item \typ{cmath} module provides math routies for complex - numbers - \item \typ{random}: provides pseudo-random number generators - for various distributions - \item These are always available and part of the standard library - \item More serious math is provided by the NumPy/SciPy modules -- - these are not standard and need to be installed separately - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Timing and profiling} - \begin{itemize} - \item Timing code: use the \typ{time} module - \item Read up on \typ{time.time()} and \typ{time.clock()} - \item \typ{timeit}: is a better way of doing timing - \item IPython has handy \typ{time} and \typ{timeit} macros (type - \typ{timeit?} for help) - \item IPython lets you debug and profile code via the \typ{run} - macro (type \typ{run?} on the prompt to learn more) - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Odds and ends} - \begin{itemize} - \item \typ{dir([object])} function: attributes of given object - \item \typ{type(object)}: returns type information - \item \typ{str(), repr()}: convert object to string representation - \item \typ{isinstance, issubclass} - \item \typ{assert} statements let you do debugging assertions in - code - \item \typ{csv} module: reading and writing CSV files - \item \typ{pickle}: lets you save and load Python objects - (\alert{serialization}) - \item \typ{sys.argv}: command line arguments - \item \typ{os.path}: common path manipulations - \item Check out the Python Library reference: - \url{http://docs.python.org/lib/lib.html} - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Test driven development (TDD)} - \begin{itemize} - \item Why? - \begin{itemize} - - \item Forces you to write reusable code! - - \item Think about the API - - \item More robust - - \item Makes refactoring very easy - - \end{itemize} - \item How? Python offers three major ways of doing this - \begin{itemize} - \item doctest - \item unittest - \item nosetest (and similar like py.test) - \end{itemize} - - \item Test every piece of functionality you offer - - \item This isn't a formal introduction but more a practical one - - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Unit test} -\begin{lstlisting} -import unittest - -class MyTestCase(unittest.TestCase): - def setUp(self): - # Called *before* each test_* - def tearDown(self): - # Called *after* each test_* - def test_something(self): - "docstring" - # Test code. - self.assertEqual(x, y) - self.assertRaises(ValueError, func, arg1, arg2 ...) - -if __name__ == '__main__': - unittest.main() -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Nosetest} -\begin{lstlisting} -import particle -def test_particle(): - # Use asserts here. - p = particle.Particle(1.0) - assert p.property[0] == 1.0 - assert p.property[2] == 0.0 - -if __name__ == '__main__': - import nose - nose.main() -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Testing} - \begin{itemize} - \item More details: see library reference and search for nosetest - \end{itemize} -\end{frame} - -\section{Numerics \& Plotting} - -\subsection{NumPy Arrays} - -\subsection{Plotting: Matplotlib} - -\begin{frame} - \frametitle{About \texttt{matplotlib}} - \begin{itemize} - \item Easy to use, scriptable, ``Matlab-like'' 2D plotting - \item Publication quality figures and interactive capabilities - \item Plots, histograms, power spectra, bar charts, errorcharts, - scatterplots, etc. - \item Also does polar plots, maps, contours - \item Support for simple \TeX\ markup - \item Multiple output backends (images, EPS, SVG, wx, Agg, Tk, GTK) - \item Cross-platform: Linux, Win32, Mac OS X - \item Good idea to use via IPython: \typ{ipython -pylab} - \item From scripts use: \typ{import pylab} - \end{itemize} -\end{frame} - -\begin{frame} - \frametitle{More information} - \begin{itemize} - \item More information here: \url{http://matplotlib.sf.net} - \item \url{http://matplotlib.sf.net/tutorial.html} - \item \url{http://matplotlib.sf.net/screenshots.html} - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Basic plotting with \texttt{matplotlib}} -\begin{lstlisting} ->>> x = arange(0, 2*pi, 0.05) ->>> plot(x, sin(x)) # Same as plot(x, sin(x), 'b-') ->>> plot(x, sin(x), 'ro') ->>> axis([0,2*pi, -1,1]) ->>> xlabel(r'$\chi$', color='g') ->>> ylabel(r'sin($\chi$)', color='r') ->>> title('A simple figure', fontsize=20) ->>> savefig('/tmp/test.eps') -# Multiple plots in one figure ->>> t = arange(0.0, 5.2, 0.2) -# red dashes, blue squares and green triangles ->>> plot(t, t, 'r--', t, t**2, 'bs', t, t**3, 'g^') -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Basic plotting \ldots} -\begin{lstlisting} -# Set properties of objects: ->>> plot(x, sin(x), linewidth=2.0, color='r') ->>> l, = plot(x, sin(x)) ->>> setp(l, linewidth=2.0, color='r') ->>> l.set_linewidth(2.0); l.set_color('r') ->>> draw() # Redraws current figure. ->>> setp(l) # Prints available properties ->>> close() # Closes the figure. -# Multiple figures: ->>> figure(1); plot(x, sin(x)) ->>> figure(2); plot(x, tanh(x)) ->>> figure(1); title('Easy as 1,2,3') -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Basic plotting \ldots} -\begin{lstlisting} ->>> figure(1) ->>> subplot(211) # Same as subplot(2, 1, 1) ->>> plot(x, cos(5*x)*exp(-x)) ->>> subplot(2, 1, 2) ->>> plot(x, cos(5*x), 'r--', label='cosine') ->>> plot(x, sin(5*x), 'g--', label='sine') ->>> legend() # Or legend(['cosine', 'sine']) ->>> text(1,0, '(1,0)') ->>> axes = gca() # Current axis ->>> fig = gcf() # Current figure -\end{lstlisting} -\end{frame} - - -\subsection{SciPy} - -\begin{frame} - \frametitle{Using \texttt{SciPy}} - \begin{itemize} - \item SciPy is Open Source software for mathematics, science, and - engineering - \item \typ{import scipy} - \item Built on NumPy - \item Provides modules for statistics, optimization, integration, - linear algebra, Fourier transforms, signal and image processing, - genetic algorithms, ODE solvers, special functions, and more - \item Used widely by scientists world over - \item Details are beyond the scope of this tutorial - \end{itemize} -\end{frame} - -\section{Standard library} - -\subsection{Quick Tour} - -\begin{frame} - \frametitle{Standard library} - \begin{itemize} - \item Very powerful - \item ``Batteries included'' - \item Example standard modules taken from the tutorial - \begin{itemize} - \item Operating system interface: \typ{os} - \item System, Command line arguments: \typ{sys} - \item Regular expressions: \typ{re} - \item Math: \typ{math}, \typ{random} - \item Internet access: \typ{urllib2}, \typ{smtplib} - \item Data compression: \typ{zlib}, \typ{gzip}, \typ{bz2}, - \typ{zipfile}, and \typ{tarfile} - \item Unit testing: \typ{doctest} and \typ{unittest} - \item And a whole lot more! - \end{itemize} - \item Check out the Python Library reference: - \url{http://docs.python.org/lib/lib.html} - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Stdlib: examples} -\begin{lstlisting} ->>> import os ->>> os.system('date') -Fri Jun 10 22:13:09 IST 2005 -0 ->>> os.getcwd() -'/home/prabhu' ->>> os.chdir('/tmp') ->>> import os ->>> dir(os) -<returns a list of all module functions> ->>> help(os) -<extensive manual page from module's docstrings> -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Stdlib: examples} -\begin{lstlisting} ->>> import sys ->>> # Print the list of command line args to Python -... print sys.argv -[''] ->>> import re # Regular expressions ->>> re.findall(r'\bf[a-z]*', -... 'which foot or hand fell fastest') -['foot', 'fell', 'fastest'] ->>> re.sub(r'(\b[a-z]+) \1', r'\1', -... 'cat in the the hat') -'cat in the hat' -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Stdlib: examples} -\begin{lstlisting} ->>> import math ->>> math.cos(math.pi / 4.0) -0.70710678118654757 ->>> math.log(1024, 2) -10.0 ->>> import random ->>> random.choice(['apple', 'pear', 'banana']) -'pear' -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Stdlib: examples} -\begin{lstlisting} ->>> import urllib2 ->>> f = urllib2.urlopen('http://www.python.org/') ->>> print f.read(100) -<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> -<?xml-stylesheet href="./css/ht2html -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Stdlib: examples} -\begin{lstlisting} ->>> import zlib ->>> s = 'witch which has which witches wrist watch' ->>> len(s) -41 ->>> t = zlib.compress(s) ->>> len(t) -37 ->>> zlib.decompress(t) -'witch which has which witches wrist watch' ->>> zlib.crc32(t) --1438085031 -\end{lstlisting} -\end{frame} - -\begin{frame} - \frametitle{Summary} - \begin{itemize} - \item Introduced Python - \item Basic syntax - \item Basic types and data structures - \item Control flow - \item Functions - \item Modules - \item Exceptions - \item Classes - \item Standard library - \end{itemize} -\end{frame} - -\end{document} - -\subsection{Basic data structures} -\begin{frame}{Lists} - \begin{itemize} - \item \texttt{species = [ 'humans', 'orcs', 'elves', 'dwarves' ]} - \item \texttt{ ids = [ 107, 109, 124, 141, 142, 144 ]} - \item \texttt{ oneliners = [ 'I will be back', 'Do or do not! No try!!', 42 ] } - \end{itemize} - - \begin{block}{List operations} - ids + [ 100, 102 ]\\ - species.append( 'unicorns')\\ - print oneliners[ 1 ]\\ - look up \alert{docs.python.org/tutorial/datastructures.html} - \end{block} -\end{frame} -\end{document} -\section{Python Tutorial} -\subsection{Preliminaries} -\begin{frame} - \frametitle{Using the interpreter} - \begin{itemize} - \item Starting up: \typ{python} or \typ{ipython} - \item Quitting: \typ{Control-D} or \typ{Control-Z} (on Win32) - \item Can use it like a calculator - \item Can execute one-liners via the \typ{-c} option: - \typ{python -c "print 'hello world'"} - \item Other options via \typ{python -h} - \end{itemize} -\end{frame} - -\begin{frame} - \frametitle{IPython} - \begin{itemize} - \item Recommended interpreter, IPython: - \url{http://ipython.scipy.org} - \item Better than the default Python shell - \item Supports tab completion by default - \item Easier object introspection - \item Shell access! - \item Command system to allow extending its own behavior - \item Supports history (across sessions) and logging - \item Can be embedded in your own Python code - \item Support for macros - \item A flexible framework for your own custom interpreter - \item Other miscellaneous conveniences - \item We'll get back to this later - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Basic IPython features} - \begin{itemize} - \item Startup: \verb+ipython [options] files+ - \begin{itemize} - \item \verb+ipython [-wthread|-gthread|-qthread]+: - Threading modes to support wxPython, pyGTK and Qt - \item \verb+ipython -pylab+: Support for matplotlib - \end{itemize} - \item TAB completion: - \begin{itemize} - \item Type \verb+object_name.<TAB>+ to see list of options - \item Also completes on file and directory names - \end{itemize} - \item \verb+object?+ shows docstring/help for any Python object - \item \verb+object??+ presents more docs (and source if possible) - \item Debugging with \verb+%pdb+ magic: pops up pdb on errors - \item Access history (saved over earlier sessions also) - \begin{itemize} - \item Use \texttt{<UpArrow>}: move up history - \item Use \texttt{<Ctrl-r> string}: search history backwards - \item Use \texttt{Esc >}: get back to end of history - \end{itemize} - \item \verb+%run [options] file[.py]+ lets you run Python code - \end{itemize} -\end{frame} -% LocalWords: BDFL Guido Rossum PSF Nokia OO Zope CMS RedHat SciPy MayaVi spam -% LocalWords: IPython ipython stdin TypeError dict int elif PYTHONPATH IOError -% LocalWords: namespace Namespaces SyntaxError ZeroDivisionError NameError str -% LocalWords: ValueError subclassed def - - - \item Types are of two kinds: \alert{mutable} and \alert{immutable} - \item Immutable types: numbers, strings, \typ{None} and tuples - \item Immutables cannot be changed ``in-place'' - \item Mutable types: lists, dictionaries, instances, etc. - \item Mutable objects can be ``changed'' - \end{itemize} - - -\begin{frame} - \frametitle{Important!} - \begin{itemize} - \item Assignment to an object is by reference - \item Essentially, \alert{names are bound to objects} - \end{itemize} -\end{frame} - - -\end{document} -\begin{frame}[fragile] - \frametitle{Dictionaries} - \begin{itemize} - \item Associative arrays/mappings - \item Indexed by ``keys'' (keys must be immutable) - \item \typ{dict[key] = value} - \item \typ{keys()} returns all keys of the dict - \item \typ{values()} returns the values of the dict - \item \verb+has_key(key)+ returns if \typ{key} is in the dict - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Dictionaries: example} - \begin{lstlisting} ->>> tel = {'jack': 4098, 'sape': 4139} ->>> tel['guido'] = 4127 ->>> tel -{'sape': 4139, 'guido': 4127, 'jack': 4098} ->>> tel['jack'] -4098 ->>> del tel['sape'] ->>> tel['irv'] = 4127 ->>> tel -{'guido': 4127, 'irv': 4127, 'jack': 4098} ->>> tel.keys() -['guido', 'irv', 'jack'] ->>> tel.has_key('guido') -True - \end{lstlisting} -\end{frame} - -\subsection{Control flow, functions} - - - -\begin{frame}[fragile] - \frametitle{\typ{If} example} - \begin{lstlisting} ->>> a = ['cat', 'window', 'defenestrate'] ->>> if 'cat' in a: -... print "meaw" -... -meaw ->>> pets = {'cat': 1, 'dog':2, 'croc': 10} ->>> if 'croc' in pets: -... print pets['croc'] -... -10 - \end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{\typ{for} example} - \begin{lstlisting} ->>> a = ['cat', 'window', 'defenestrate'] ->>> for x in a: -... print x, len(x) -... -cat 3 -window 6 -defenestrate 12 ->>> knights = {'gallahad': 'the pure', -... 'robin': 'the brave'} ->>> for k, v in knights.iteritems(): -... print k, v -... -gallahad the pure -robin the brave -\end{lstlisting} -\end{frame} diff --git a/day2/PythonMachinery.tex b/day2/PythonMachinery.tex deleted file mode 100755 index bd2a074..0000000 --- a/day2/PythonMachinery.tex +++ /dev/null @@ -1,325 +0,0 @@ -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% Tutorial slides on Python. -% -% Author: Prabhu Ramachandran <prabhu at aero.iitb.ac.in> -% Copyright (c) 2005-2008, Prabhu Ramachandran -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -\documentclass[14pt,compress]{beamer} -%\documentclass[draft]{beamer} -%\documentclass[compress,handout]{beamer} -%\usepackage{pgfpages} -%\pgfpagesuselayout{2 on 1}[a4paper,border shrink=5mm] - -% Modified from: generic-ornate-15min-45min.de.tex -\mode<presentation> -{ - \usetheme{Warsaw} - \useoutertheme{split} - \setbeamercovered{transparent} -} - -\usepackage[english]{babel} -\usepackage[latin1]{inputenc} -%\usepackage{times} -\usepackage[T1]{fontenc} - -% Taken from Fernando's slides. -\usepackage{ae,aecompl} -\usepackage{mathpazo,courier,euler} -\usepackage[scaled=.95]{helvet} - -\definecolor{darkgreen}{rgb}{0,0.5,0} - -\usepackage{listings} -\lstset{language=Python, - basicstyle=\ttfamily\bfseries, - commentstyle=\color{red}\itshape, - stringstyle=\color{darkgreen}, - showstringspaces=false, - keywordstyle=\color{blue}\bfseries} - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% Macros -\setbeamercolor{emphbar}{bg=blue!20, fg=black} -\newcommand{\emphbar}[1] -{\begin{beamercolorbox}[rounded=true]{emphbar} - {#1} - \end{beamercolorbox} -} -\newcounter{time} -\setcounter{time}{0} -\newcommand{\inctime}[1]{\addtocounter{time}{#1}{\tiny \thetime\ m}} - -\newcommand{\typ}[1]{\texttt{#1}} - -\newcommand{\kwrd}[1]{ \texttt{\textbf{\color{blue}{#1}}} } - -%%% This is from Fernando's setup. -% \usepackage{color} -% \definecolor{orange}{cmyk}{0,0.4,0.8,0.2} -% % Use and configure listings package for nicely formatted code -% \usepackage{listings} -% \lstset{ -% language=Python, -% basicstyle=\small\ttfamily, -% commentstyle=\ttfamily\color{blue}, -% stringstyle=\ttfamily\color{orange}, -% showstringspaces=false, -% breaklines=true, -% postbreak = \space\dots -% } - - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% Title page -\title[Basic Python]{Python,\\a great programming toolkit:\\ -numerics and plotting} - -\author[Asokan \& Prabhu] {Asokan Pichai\\Prabhu Ramachandran} - -\institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay} -\date[] {26, July 2009} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%\pgfdeclareimage[height=0.75cm]{iitmlogo}{iitmlogo} -%\logo{\pgfuseimage{iitmlogo}} - - -%% Delete this, if you do not want the table of contents to pop up at -%% the beginning of each subsection: -\AtBeginSubsection[] -{ - \begin{frame}<beamer> - \frametitle{Outline} - \tableofcontents[currentsection,currentsubsection] - \end{frame} -} - -\AtBeginSection[] -{ - \begin{frame}<beamer> - \frametitle{Outline} - \tableofcontents[currentsection,currentsubsection] - \end{frame} -} - -% If you wish to uncover everything in a step-wise fashion, uncomment -% the following command: -%\beamerdefaultoverlayspecification{<+->} - -%\includeonlyframes{current,current1,current2,current3,current4,current5,current6} - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% DOCUMENT STARTS -\begin{document} - -\begin{frame} - \frametitle{Outline} - \tableofcontents -\end{frame} -\section{Pythonicity} -\begin{frame}[fragile] - \frametitle{The Zen of Python} - -Try this! - -\begin{lstlisting} ->>> import this -\end{lstlisting} - -\end{frame} - -\begin{frame} - {Style Guide} - - Read PEP8 - - \url{http://www.python.org/dev/peps/pep-0008/} - - \inctime{10} -\end{frame} -\section{More Python Machinery} -\subsection{Objects} -\begin{frame}{Objects in Python} - \begin{itemize} - \item What is an Object? (Types and classes) - \item identity - \item type - \item method - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Why are they useful?} - \small - \begin{lstlisting} -for element in (1, 2, 3): - print element -for key in {'one':1, 'two':2}: - print key -for char in "123": - print char -for line in open("myfile.txt"): - print line -for line in urllib2.urlopen('http://site.com'): - print line - \end{lstlisting} -\end{frame} -\begin{frame}{And the winner is \ldots OBJECTS!} - All objects providing a similar inteface can be used the same way.\\ - Functions (and others) are first-class objects. Can be passed to and returned from functions. - \inctime{10} -\end{frame} -\subsection{Dictionary} -\begin{frame}{Dictionary} - \begin{itemize} - \item aka associative arrays, key-value pairs, hashmaps, hashtables \ldots - \item \typ{ d = \{ ``Hitchhiker's guide'' : 42, ``Terminator'' : ``I'll be back''\}} - \item lists and tuples index: 0 \ldots n - \item dictionaries index using strings - \item aka key-value pairs - \item what can be keys? - \end{itemize} -\end{frame} - -\begin{frame}{Dict \ldots } - \begin{itemize} - \item \alert{Unordered} - \begin{block}{Standard usage} - for key in dict:\\ - <use> dict[key] \# => value - \end{block} - \item \typ{d.keys()} returns a list - \item can we have duplicate keys? - \end{itemize} -\end{frame} -\begin{frame} {Problem Set 2.1} - \begin{description} -\item[2.1.1] You are given date strings of the form ``29, Jul 2009'', or ``4 January 2008''. In other words a number a string and another number, with a comma sometimes separating the items.Write a function that takes such a string and returns a tuple (yyyy, mm, dd) where all three elements are ints. - \item[2.1.2] Count word frequencies in a file. - \item[2.1.3] Find the most used Python keywords in your Python code (import keyword). -\end{description} - -\inctime{20} -\end{frame} - -\subsection{Set} -\begin{frame}[fragile] - \frametitle{Set} - \begin{itemize} - \item Simplest container, mutable - \item No ordering, no duplicates - \item usual suspects: union, intersection, subset \ldots - \item >, >=, <, <=, in, \ldots - \end{itemize} - \begin{lstlisting} -f10 = set([1,2,3,5,8]) -p10 = set([2,3,5,7]) -f10|p10, f10&p10 -f10-p10, p10-f10, f10^p10 -set([2,3]) < p10, set([2,3]) <= p10 -2 in p10, 4 in p10 -len(f10) -\end{lstlisting} -\end{frame} - -\begin{frame} - \frametitle{Problem set 2.2} - \begin{description} - \item[2.2.1] Given a dictionary of the names of students and their marks, identify how many duplicate marks are there? and what are these? - \item[2.2.2] Given a string of the form ``4-7, 9, 12, 15'' find the numbers missing in this list for a given range. -\end{description} -\inctime{15} -\end{frame} - -\subsection{Functions Reloaded!} -\begin{frame}[fragile] - \frametitle{Advanced functions} - \begin{itemize} - \item default args - \item varargs - \item keyword args - \item scope - \item \typ{global} - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Functions: default arguments} - \begin{lstlisting} -def ask_ok(prompt, retries=4, complaint='Yes or no!'): - while True: - ok = raw_input(prompt) - if ok in ('y', 'ye', 'yes'): - return True - if ok in ('n', 'no', 'nop', 'nope'): - return False - retries = retries - 1 - if retries < 0: - raise IOError, 'bad user' - print complaint - \end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Functions: keyword arguments} - \small - \begin{lstlisting} -def parrot(voltage, state='a stiff', - action='voom', type='Royal Blue'): - print "-- This parrot wouldn't", action, - print "if you supply", voltage, "Volts." - print "-- Lovely plumage, the", type - print "-- It's", state, "!" - -parrot(1000) -parrot(action = 'VOOOOOM', voltage = 1000000) -parrot('a thousand', state = 'pushing up the daisies') -parrot('a million', 'bereft of life', 'jump') -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Functions: arbitrary argument lists} - \begin{itemize} - \item Arbitrary number of arguments using \verb+*args+ or - \verb+*whatever+ - \item Keyword arguments using \verb+**kw+ - \item Given a tuple/dict how do you call a function? - \begin{itemize} - \item Using argument unpacking - \item For positional arguments: \verb+foo(*[5, 10])+ - \item For keyword args: \verb+foo(**{'a':5, 'b':10})+ - \end{itemize} - \end{itemize} -\end{frame} - - \begin{frame}[fragile] -\begin{lstlisting} -def foo(a=10, b=100): - print a, b -def func(*args, **keyword): - print args, keyword -# Unpacking: -args = [5, 10] -foo(*args) -kw = {'a':5, 'b':10} -foo(**kw) -\end{lstlisting} - \inctime{15} -\end{frame} - -\subsection{Functional programming} -\begin{frame}[fragile] - \frametitle{Functional programming} -What is the basic idea?\\ -Why is it interesting?\\ -\typ{map, reduce, filter}\\ -list comprehension\\ -generators - \inctime{10} -\end{frame} -\end{document} - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% diff --git a/day2/session1.tex b/day2/session1.tex deleted file mode 100644 index 5ba1c0d..0000000 --- a/day2/session1.tex +++ /dev/null @@ -1,832 +0,0 @@ -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% Tutorial slides on Python. -% -% Author: Prabhu Ramachandran <prabhu at aero.iitb.ac.in> -% Copyright (c) 2005-2009, Prabhu Ramachandran -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -\documentclass[14pt,compress]{beamer} -%\documentclass[draft]{beamer} -%\documentclass[compress,handout]{beamer} -%\usepackage{pgfpages} -%\pgfpagesuselayout{2 on 1}[a4paper,border shrink=5mm] - -% Modified from: generic-ornate-15min-45min.de.tex -\mode<presentation> -{ - \usetheme{Warsaw} - \useoutertheme{split} - \setbeamercovered{transparent} -} - -\usepackage[english]{babel} -\usepackage[latin1]{inputenc} -%\usepackage{times} -\usepackage[T1]{fontenc} - -% Taken from Fernando's slides. -\usepackage{ae,aecompl} -\usepackage{mathpazo,courier,euler} -\usepackage[scaled=.95]{helvet} - -\definecolor{darkgreen}{rgb}{0,0.5,0} - -\usepackage{listings} -\lstset{language=Python, - basicstyle=\ttfamily\bfseries, - commentstyle=\color{red}\itshape, - stringstyle=\color{darkgreen}, - showstringspaces=false, - keywordstyle=\color{blue}\bfseries} - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% Macros -\setbeamercolor{emphbar}{bg=blue!20, fg=black} -\newcommand{\emphbar}[1] -{\begin{beamercolorbox}[rounded=true]{emphbar} - {#1} - \end{beamercolorbox} -} -\newcounter{time} -\setcounter{time}{0} -\newcommand{\inctime}[1]{\addtocounter{time}{#1}{\tiny \thetime\ m}} - -\newcommand{\typ}[1]{\lstinline{#1}} - -\newcommand{\kwrd}[1]{ \texttt{\textbf{\color{blue}{#1}}} } - -%%% This is from Fernando's setup. -% \usepackage{color} -% \definecolor{orange}{cmyk}{0,0.4,0.8,0.2} -% % Use and configure listings package for nicely formatted code -% \usepackage{listings} -% \lstset{ -% language=Python, -% basicstyle=\small\ttfamily, -% commentstyle=\ttfamily\color{blue}, -% stringstyle=\ttfamily\color{orange}, -% showstringspaces=false, -% breaklines=true, -% postbreak = \space\dots -% } - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% Title page -\title[]{Arrays\\ \& \\2D Plotting} - -\author[FOSSEE Team] {FOSSEE} - -\institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay} -\date[] {11, October 2009} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%\pgfdeclareimage[height=0.75cm]{iitmlogo}{iitmlogo} -%\logo{\pgfuseimage{iitmlogo}} - - -%% Delete this, if you do not want the table of contents to pop up at -%% the beginning of each subsection: -\AtBeginSubsection[] -{ - \begin{frame}<beamer> - \frametitle{Outline} - \tableofcontents[currentsection,currentsubsection] - \end{frame} -} - -\AtBeginSection[] -{ - \begin{frame}<beamer> - \frametitle{Outline} - \tableofcontents[currentsection,currentsubsection] - \end{frame} -} - -\newcommand{\num}{\texttt{numpy}} - - -% If you wish to uncover everything in a step-wise fashion, uncomment -% the following command: -%\beamerdefaultoverlayspecification{<+->} - -%\includeonlyframes{current,current1,current2,current3,current4,current5,current6} - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% DOCUMENT STARTS -\begin{document} - -\begin{frame} - \maketitle -\end{frame} - -\begin{frame} - \frametitle{Outline} - \tableofcontents - % You might wish to add the option [pausesections] -\end{frame} - -\section{Arrays} - -\subsection{Basic \typ{numpy}} - -\begin{frame} - \frametitle{The \num\ module} - \begin{itemize} - \item Why? - \item What: - \begin{itemize} - \item An efficient and powerful array type for various common data types - \item Abstracts out the most commonly used standard operations on arrays - \end{itemize} - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Examples of \num} -\begin{lstlisting} -# Simple array math example ->>> from numpy import * ->>> a = array([1,2,3,4]) ->>> b = arange(2,6) ->>> b -array([2,3,4,5]) ->>> a*2 + b + 1 # Basic math! -array([5, 8, 11, 14]) -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Examples of \num} -\begin{lstlisting} -# Pi and e are defined. ->>> x = linspace(0.0, 10.0, 1000) ->>> x *= 2*pi/10 # inplace. -# apply functions to array. ->>> y = sin(x) ->>> z = exp(y) -\end{lstlisting} -\inctime{5} -\end{frame} - -\begin{frame}[fragile] - \frametitle{More examples of \num} -\vspace*{-8pt} -\begin{lstlisting} ->>> x = array([1., 2, 3, 4]) ->>> size(x) -4 ->>> x.dtype # What is a.dtype? -dtype('float64') ->>> x.shape -(4,) ->>> print x.itemsize -8 ->>> x[0] = 10 ->>> print x[0], x[-1] -10.0 4.0 -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Multi-dimensional arrays} -\begin{lstlisting} ->>> a = array([[ 0, 1, 2, 3], -... [10,11,12,13]]) ->>> a.shape # (rows, columns) -(2, 4) ->>> a.shape=4,2 -# Accessing and setting values ->>> a[1][3] ->>> a[1,3] ->>> a[1,3] = -1 ->>> a[1] # The second row -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Array math} - \begin{itemize} - \item Basic \alert{elementwise} math (given two arrays \typ{a, b}): - \typ{+, -, *, /, \%} - \item Inplace operators: \typ{a += b} - \item \typ{sum(x, axis=0)}, - \typ{product(x, axis=0)}, - \typ{dot(a, bp)} - \end{itemize} -\begin{lstlisting} ->>> x = array([[0,2,4,2],[1,2,3,4]]) ->>> sum(x) ->>> sum(x,axis=1) -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Array math cont.} - \begin{itemize} - \item Logical operations: \typ{==}, \typ{!=}, - \typ{<}, \typ{>} etc. - \item Trig and other functions: \typ{sin(x),} - \typ{arcsin(x), sinh(x),} - \typ{exp(x), sqrt(x)} etc. - \end{itemize} -\begin{lstlisting} ->>> a<4, a!=3 ->>> sqrt(a) -\end{lstlisting} -\inctime{10} -\end{frame} - -\begin{frame} - \frametitle{Summary of Concepts} - \begin{itemize} - \item fixed size (\typ{arr.size}); - \item Same type (\typ{arr.dtype}) of data - \item arbitrary dimensionality - \item \typ{arr.shape}: size in each dimension - \item \alert{Note:} \typ{len(arr) != arr.size} in general - \item \alert{Note:} By default array operations are performed - \alert{elementwise} - \end{itemize} -\end{frame} - -\subsection{Array Creation \& Slicing, Striding Arrays} - -\begin{frame}[fragile] - \frametitle{Array creation functions} - \begin{itemize} - \item \typ{array?} \alert{\#Doc string reading} - \item \typ{array(object,dtype=None,...)} - \begin{lstlisting} ->>> array([2,3,4]) -array([2, 3, 4]) - \end{lstlisting} - \item \typ{linspace(start,stop,num)} - \begin{lstlisting} ->>> linspace(0, 2, 4) -array([0.,0.6666667,1.3333333,2.]) - \end{lstlisting} - \item \typ{arange?} - \alert{\# float version of range} - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Array creation functions cont.} - \begin{itemize} - \item \typ{ones(shape, dtype=None, ...)} - \begin{lstlisting} ->>> ones((2,2)) -array([[ 1., 1.], - [ 1., 1.]]) - \end{lstlisting} - \item \typ{identity(n)} - \item \typ{ones\_like(x)} - \begin{lstlisting} ->>> a = array([[1,2,3],[4,5,6]]) ->>> ones_like(a) -array([[1, 1, 1], - [1, 1, 1]]) - \end{lstlisting} - \item Also try \typ{zeros, zeros\_like, empty} - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Slicing arrays} -\begin{lstlisting} ->>> a = array([[1,2,3], [4,5,6], - [7,8,9]]) ->>> a[0,1:3] -array([2, 3]) ->>> a[1:,1:] -array([[5, 6], - [8, 9]]) ->>> a[:,2] -array([3, 6, 9]) -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Striding arrays} -\begin{lstlisting} ->>> a[0::2,0::2] -array([[1, 3], - [7, 9]]) -# Slices are references to the -# same memory! -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] -\frametitle{Random Numbers} -\begin{lstlisting} ->>> random.random() -0.94134734326214331 ->>> random.random(2) -array([ 0.73955352, 0.49463645]) ->>> random.random(3,2) -array([[ 0.96276665, 0.77174861], - [ 0.35138557, 0.61462271], - [ 0.16789255, 0.43848811]]) -\end{lstlisting} -\inctime{15} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Problem} - Finite difference - \begin{equation*} - \frac{sin(x+h)-sin(x)}{h} - \end{equation*} - \begin{lstlisting} - >>> x = linspace(0,2*pi,100) - >>> y = sin(x) - >>> deltax = x[1]-x[0] - \end{lstlisting} - \pause - \begin{enumerate} - \item Given this, get the finite difference of sin in the range 0 to 2*pi - \end{enumerate} -\end{frame} - - -\begin{frame}[fragile] - \frametitle{Advanced Problem} - \begin{lstlisting} - >>> from scipy import misc - >>> A=misc.imread('filename') - >>> misc.imshow(A) - \end{lstlisting} - \begin{enumerate} - \item Convert an RGB image to Grayscale. $ Y = 0.5R + 0.25G + 0.25B $ - \item Scale the image to 50\% - \item Introduce some random noise - \item Smooth the image using a mean filter - \\\small{Each element in the array is replaced by mean of all the neighbouring elements} - \\\small{How fast does your code run?} - \end{enumerate} -\inctime{15} -\end{frame} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -\section{2D Plotting} -\subsection{Getting Started} - -\begin{frame} - {IPython's \typ{pylab} mode} -\begin{block}{Immediate use -} - \typ{\$ ipython -pylab} -\end{block} -\begin{itemize} - \item \typ{pylab}: convenient 2D plotting interface to MPL - \item Imports all of pylab for you! - \item Allows for interactive plotting -\end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Basic 2D plotting} - -\begin{lstlisting} ->>> x = linspace(0, 2*pi, 1000) ->>> plot(x, sin(x)) ->>> plot(x, sin(x), 'ro') ->>> xlabel(r'$\chi$', color='g') -# LaTeX markup! ->>> ylabel(r'sin($\chi$)', color='r') ->>> title('Simple figure', fontsize=20) ->>> savefig('/tmp/test.png') -\end{lstlisting} -\begin{itemize} - \item Also: PS, EPS, SVG, PDF -\end{itemize} -\inctime{5} -\end{frame} - -\subsection{Plots - Lines, Labels and Legends} -\begin{frame}[fragile] - \frametitle{Tweaking plots} -\begin{lstlisting} -# Set properties of objects: ->>> l, = plot(x, sin(x)) -# Why "l,"? ->>> setp(l, linewidth=2.0, color='r') ->>> l.set_linewidth(2.0) ->>> draw() # Redraw. ->>> setp(l) # Print properties. ->>> clf() # Clear figure. ->>> close() # Close figure. -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Working with text \ldots} -%\begin{itemize} -% \item We already saw LaTeX markup support! -%\end{itemize} -\begin{lstlisting} ->>> w = arange(-2,2,.1) ->>> plot(w,exp(-(w*w))*cos) ->>> ylabel('$f(\omega)$') ->>> xlabel('$\omega$') ->>> title(r"$f(\omega)=e^{-\omega^2} - cos({\omega^2})$") -\end{lstlisting} - -\end{frame} - -\begin{frame}[fragile] - \frametitle{Legends} -\begin{lstlisting} ->>> x = linspace(0, 2*pi, 1000) ->>> plot(x, cos(5*x), 'r--', - label='cosine') ->>> plot(x, sin(5*x), 'g--', - label='sine') ->>> legend() -# Or use: ->>> legend(['cosine', 'sine']) -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Multiple figures} - -\begin{lstlisting} ->>> figure(1) ->>> plot(x, sin(x)) ->>> figure(2) ->>> plot(x, tanh(x)) ->>> figure(1) ->>> title('Easy as 1,2,3') -\end{lstlisting} - - -\end{frame} - -\begin{frame}[fragile] - \frametitle{\typ{pylab} in Python scripts} -\begin{lstlisting} -import pylab -x = pylab.linspace(0, 20, 1000) -pylab.plot(x, pylab.sin(x)) - -# Can also use: -from pylab import linspace, sin, plot -\end{lstlisting} -\inctime{10} -\end{frame} - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -\subsection{Types of Plots} -\begin{frame}[fragile] - \frametitle{X-Y plot} - \begin{columns} - \column{0.5\textwidth} - \hspace*{-0.5in} - \includegraphics[height=2in, interpolate=true]{data/xyplot} - \column{0.45\textwidth} - \begin{block}{Example code} - \tiny -\begin{lstlisting} -t1 = arange(0.0, 5.0, 0.1) -t2 = arange(0.0, 5.0, 0.02) -t3 = arange(0.0, 2.0, 0.01) -subplot(211) -plot(t1, cos(2*pi*t1)*exp(-t1), 'bo', - t2, cos(2*pi*t2)*exp(-t2), 'k') -grid(True) -title('A tale of 2 subplots') -ylabel('Damped') -subplot(212) -plot(t3, cos(2*pi*t3), 'r--') -grid(True) -xlabel('time (s)') -ylabel('Undamped') -\end{lstlisting} - \end{block} - \end{columns} -\end{frame} - -\begin{frame}[fragile] \frametitle{Semi-log and log-log plots} - \begin{columns} - \column{0.5\textwidth} - \hspace*{-0.5in} - \includegraphics[height=2in, interpolate=true]{data/log} - \column{0.45\textwidth} - \begin{block}{Example code} - \tiny -\begin{lstlisting} -dt = 0.01 -t = arange(dt, 20.0, dt) -subplot(311) -semilogy(t, exp(-t/5.0)) -ylabel('semilogy') -grid(True) -subplot(312) -semilogx(t, sin(2*pi*t)) -ylabel('semilogx') -grid(True) -# minor grid on too -gca().xaxis.grid(True, which='minor') -subplot(313) -loglog(t, 20*exp(-t/10.0), basex=4) -grid(True) -ylabel('loglog base 4 on x') -\end{lstlisting} - \end{block} -\end{columns} -\end{frame} - -\begin{frame}[fragile] \frametitle{Errorbar} - \begin{columns} - \column{0.5\textwidth} - \hspace*{-0.5in} - \includegraphics[height=2in, interpolate=true]{data/errorbar} - \column{0.45\textwidth} - \begin{block}{Example code} - \tiny -\begin{lstlisting} -t = arange(0.1, 4, 0.1) -s = exp(-t) -e = 0.1*abs(randn(len(s))) -f = 0.1*abs(randn(len(s))) -g = 2*e -h = 2*f -errorbar(t, s, [e,g], f, fmt='o') -xlabel('Distance (m)') -ylabel('Height (m)') -title('Mean and standard error '\ - 'as a function of distance') -\end{lstlisting} - \end{block} -\end{columns} -\end{frame} - -\begin{frame}[fragile] \frametitle{Histogram} - \begin{columns} - \column{0.5\textwidth} - \hspace*{-0.5in} - \includegraphics[height=2in, interpolate=true]{data/histogram} - \column{0.45\textwidth} - \begin{block}{Example code} - \tiny -\begin{lstlisting} -mu, sigma = 100, 15 -x = mu + sigma*randn(10000) -# the histogram of the data -n, bins, patches = hist(x, 100, normed=1) -# add a 'best fit' line -y = normpdf( bins, mu, sigma) -l = plot(bins, y, 'r--', linewidth=2) -xlim(40, 160) -xlabel('Smarts') -ylabel('P') -title(r'$\rm{IQ:}\/ \mu=100,\/ \sigma=15$') -\end{lstlisting} - \end{block} -\end{columns} -\end{frame} - -\begin{frame}[fragile] \frametitle{Bar charts} - \begin{columns} - \column{0.5\textwidth} - \hspace*{-0.5in} - \includegraphics[height=2in, interpolate=true]{data/barchart} - \column{0.45\textwidth} - \begin{block}{Example code} - \tiny -\begin{lstlisting} -N = 5 -menMeans = (20, 35, 30, 35, 27) -menStd = ( 2, 3, 4, 1, 2) -# the x locations for the groups -ind = arange(N) -# the width of the bars -width = 0.35 -p1 = bar(ind, menMeans, width, - color='r', yerr=menStd) -womenMeans = (25, 32, 34, 20, 25) -womenStd = ( 3, 5, 2, 3, 3) -p2 = bar(ind+width, womenMeans, width, - color='y', yerr=womenStd) -ylabel('Scores') -title('Scores by group and gender') -xticks(ind+width, - ('G1', 'G2', 'G3', 'G4', 'G5')) -xlim(-width,len(ind)) -yticks(arange(0,41,10)) -legend((p1[0], p2[0]), - ('Men', 'Women'), shadow=True) -\end{lstlisting} - \end{block} -\end{columns} -\end{frame} - -\begin{frame}[fragile] \frametitle{Pie charts} - \begin{columns} - \column{0.5\textwidth} - \hspace*{-0.4in} - \includegraphics[height=2.0in, interpolate=true]{data/piechart} - \column{0.45\textwidth} - \begin{block}{Example code} - \tiny -\begin{lstlisting} -# make a square figure and axes -figure(1, figsize=(8,8)) -ax = axes([0.1, 0.1, 0.8, 0.8]) -labels = 'Frogs', 'Hogs', 'Dogs', 'Logs' -fracs = [15,30,45, 10] -explode=(0, 0.05, 0, 0) -pie(fracs, explode=explode, labels=labels, - autopct='%1.1f%%', shadow=True) -title('Raining Hogs and Dogs', - bbox={'facecolor':'0.8', 'pad':5}) -\end{lstlisting} - \end{block} -\end{columns} -\end{frame} - -\begin{frame}[fragile] \frametitle{Scatter plots} - \begin{columns} - \column{0.5\textwidth} - \hspace*{-0.4in} - \includegraphics[height=2in, interpolate=true]{data/scatter} - \column{0.45\textwidth} - \begin{block}{Example code} - \tiny -\begin{lstlisting} -N = 30 -x = 0.9*rand(N) -y = 0.9*rand(N) -# 0 to 10 point radiuses -area = pi*(10 * rand(N))**2 -volume = 400 + rand(N)*450 -scatter(x,y,s=area, marker='o', c=volume, - alpha=0.75) -xlabel(r'$\Delta_i$', size='x-large') -ylabel(r'$\Delta_{i+1}$', size='x-large') -title(r'Volume and percent change') -grid(True) -colorbar() -savefig('scatter') -\end{lstlisting} - \end{block} -\end{columns} -\end{frame} - -\begin{frame}[fragile] \frametitle{Polar} - \begin{columns} - \column{0.5\textwidth} - \hspace*{-0.5in} - \includegraphics[height=2in, interpolate=true]{data/polar} - \column{0.45\textwidth} - \begin{block}{Example code} - \tiny -\begin{lstlisting} -figure(figsize=(8,8)) -ax = axes([0.1, 0.1, 0.8, 0.8], - polar=True, - axisbg='#d5de9c') -r = arange(0,1,0.001) -theta = 2*2*pi*r -polar(theta, r, color='#ee8d18', lw=3) -# the radius of the grid labels -setp(ax.thetagridlabels, y=1.075) -title(r'$\theta=4\pi r$', fontsize=20) -\end{lstlisting} - - \end{block} -\end{columns} -\end{frame} - -\begin{frame}[fragile] \frametitle{Contours} - \begin{columns} - \column{0.45\textwidth} - \hspace*{-0.5in} - \includegraphics[height=2in, interpolate=true]{data/contour} - \column{0.525\textwidth} - \begin{block}{Example code} - \tiny -\begin{lstlisting} -x = arange(-3.0, 3.0, 0.025) -y = arange(-2.0, 2.0, 0.025) -X, Y = meshgrid(x, y) -Z1 = bivariate_normal(X, Y, 1.0, 1.0, 0.0, 0.0) -Z2 = bivariate_normal(X, Y, 1.5, 0.5, 1, 1) -# difference of Gaussians -Z = 10.0 * (Z2 - Z1) -im = imshow(Z, interpolation='bilinear', - origin='lower', - cmap=cm.gray, extent=(-3,3,-2,2)) -levels = arange(-1.2, 1.6, 0.2) -# label every second level -clabel(CS, levels[1::2], inline=1, - fmt='%1.1f', fontsize=14) -CS = contour(Z, levels, - origin='lower', - linewidths=2, - extent=(-3,3,-2,2)) -# make a colorbar for the contour lines -CB = colorbar(CS, shrink=0.8, extend='both') -title('Lines with colorbar') -hot(); flag() -\end{lstlisting} - \end{block} -\end{columns} -\end{frame} - -\begin{frame}[fragile] \frametitle{Velocity vectors} - \begin{columns} - \column{0.5\textwidth} - \hspace*{-0.5in} - \includegraphics[height=2in, interpolate=true]{data/quiver} - \column{0.45\textwidth} - \begin{block}{Example code} - \tiny -\begin{lstlisting} -X,Y = meshgrid(arange(0,2*pi,.2), - arange(0,2*pi,.2) ) -U = cos(X) -V = sin(Y) -Q = quiver(X[::3, ::3], Y[::3, ::3], - U[::3, ::3], V[::3, ::3], - color='r', units='x', - linewidths=(2,), - edgecolors=('k'), - headaxislength=5 ) -qk = quiverkey(Q, 0.5, 0.03, 1, '1 m/s', - fontproperties= - {'weight': 'bold'}) -axis([-1, 7, -1, 7]) -title('triangular head; scale '\ - 'with x view; black edges') -\end{lstlisting} - \end{block} -\end{columns} -\end{frame} - -\begin{frame}[fragile] \frametitle{Maps} - \includegraphics[height=2.3in, interpolate=true]{data/plotmap} - \begin{center} - \tiny - For details see \url{http://matplotlib.sourceforge.net/screenshots/plotmap.py} - \end{center} -\end{frame} - - -\begin{frame} - \frametitle{More information} - \begin{itemize} - \item More information here: \url{http://matplotlib.sf.net} - \item \url{http://matplotlib.sf.net/tutorial.html} - \item \url{http://matplotlib.sf.net/screenshots.html} - \end{itemize} -\inctime{5} -\end{frame} - -\begin{frame} - \frametitle{Problem Set} - \begin{itemize} - \item[1] Write a function that plots any regular n-gon given \typ{n}. - \item[2] Consider the logistic map, $f(x) = kx(1-x)$, plot it for - $k=2.5, 3.5$ and $4$ in the same plot. -\end{itemize} -\end{frame} - -\begin{frame}[fragile] -\frametitle{Problem Set} - \begin{columns} - \column{0.6\textwidth} - \small{ - \begin{itemize} - \item[3] Consider the iteration $x_{n+1} = f(x_n)$ where $f(x) = kx(1-x)$. Plot the successive iterates of this process as explained below. - \end{itemize}} - \column{0.35\textwidth} - \hspace*{-0.5in} - \includegraphics[height=1.6in, interpolate=true]{data/cobweb} -\end{columns} -\end{frame} - -\begin{frame} - - Plot the cobweb plot as follows: - \begin{enumerate} - \item Start at $(x_0, 0)$ ($\implies$ i=0) - \item Draw a line to $(x_i, f(x_i))$ - \item Set $x_{i+1} = f(x_i)$ - \item Draw a line to $(x_{i+1}, x_{i+1})$ - \item $(i\implies i+1)$ - \item Repeat from 2 for as long as you want - \end{enumerate} -\inctime{20} -\end{frame} - -\begin{frame}{Summary} - \begin{itemize} - \item Basics of Numpy. - \item Array operations. - \item Plotting in 2D. - \end{itemize} -\end{frame} -\end{document} diff --git a/day2/session2.tex b/day2/session2.tex deleted file mode 100644 index 2519057..0000000 --- a/day2/session2.tex +++ /dev/null @@ -1,431 +0,0 @@ -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% Tutorial slides on Python. -% -% Author: Prabhu Ramachandran <prabhu at aero.iitb.ac.in> -% Copyright (c) 2005-2009, Prabhu Ramachandran -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -\documentclass[14pt,compress]{beamer} -%\documentclass[draft]{beamer} -%\documentclass[compress,handout]{beamer} -%\usepackage{pgfpages} -%\pgfpagesuselayout{2 on 1}[a4paper,border shrink=5mm] - -% Modified from: generic-ornate-15min-45min.de.tex -\mode<presentation> -{ - \usetheme{Warsaw} - \useoutertheme{split} - \setbeamercovered{transparent} -} - -\usepackage[english]{babel} -\usepackage[latin1]{inputenc} -%\usepackage{times} -\usepackage[T1]{fontenc} - -% Taken from Fernando's slides. -\usepackage{ae,aecompl} -\usepackage{mathpazo,courier,euler} -\usepackage[scaled=.95]{helvet} - -\definecolor{darkgreen}{rgb}{0,0.5,0} - -\usepackage{listings} -\lstset{language=Python, - basicstyle=\ttfamily\bfseries, - commentstyle=\color{red}\itshape, - stringstyle=\color{darkgreen}, - showstringspaces=false, - keywordstyle=\color{blue}\bfseries} - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% Macros -\setbeamercolor{emphbar}{bg=blue!20, fg=black} -\newcommand{\emphbar}[1] -{\begin{beamercolorbox}[rounded=true]{emphbar} - {#1} - \end{beamercolorbox} -} -\newcounter{time} -\setcounter{time}{0} -\newcommand{\inctime}[1]{\addtocounter{time}{#1}{\tiny \thetime\ m}} - -\newcommand{\typ}[1]{\lstinline{#1}} - -\newcommand{\kwrd}[1]{ \texttt{\textbf{\color{blue}{#1}}} } - -%%% This is from Fernando's setup. -% \usepackage{color} -% \definecolor{orange}{cmyk}{0,0.4,0.8,0.2} -% % Use and configure listings package for nicely formatted code -% \usepackage{listings} -% \lstset{ -% language=Python, -% basicstyle=\small\ttfamily, -% commentstyle=\ttfamily\color{blue}, -% stringstyle=\ttfamily\color{orange}, -% showstringspaces=false, -% breaklines=true, -% postbreak = \space\dots -% } - - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% Title page -\title[]{Numerical Computing with Numpy \& Scipy} - -\author[FOSSEE Team] {FOSSEE} - -\institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay} -\date[] {11, October 2009} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%\pgfdeclareimage[height=0.75cm]{iitmlogo}{iitmlogo} -%\logo{\pgfuseimage{iitmlogo}} - - -%% Delete this, if you do not want the table of contents to pop up at -%% the beginning of each subsection: -\AtBeginSubsection[] -{ - \begin{frame}<beamer> - \frametitle{Outline} - \tableofcontents[currentsection,currentsubsection] - \end{frame} -} - -\AtBeginSection[] -{ - \begin{frame}<beamer> - \frametitle{Outline} - \tableofcontents[currentsection,currentsubsection] - \end{frame} -} - -% If you wish to uncover everything in a step-wise fashion, uncomment -% the following command: -%\beamerdefaultoverlayspecification{<+->} - -%\includeonlyframes{current,current1,current2,current3,current4,current5,current6} - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% DOCUMENT STARTS -\begin{document} - -\begin{frame} - \maketitle -\end{frame} - -\section{Advanced Numpy} -\begin{frame}[fragile] - \frametitle{Broadcasting} - \begin{lstlisting} - >>> a = arange(4) - >>> b = arange(5) - >>> a+b #Does this work? - >>> a+3 - >>> c = array([3]) - >>> a+c #Works! - >>> b+c #But how? - >>> a.shape, b.shape, c.shape - \end{lstlisting} - \begin{itemize} - \item Enter Broadcasting! - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Broadcasting} - \begin{columns} - \column{0.65\textwidth} - \hspace*{-1.5in} - \begin{lstlisting} - >>> a = arange(4) - >>> a+3 - array([3, 4, 5, 6]) - \end{lstlisting} - \column{0.35\textwidth} - \includegraphics[height=0.7in, interpolate=true]{data/broadcast_scalar} - \end{columns} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Broadcasting in 3D} - \begin{lstlisting} - >>> x = ones((3, 5, 1)) - >>> y = ones(8) - >>> (x + y).shape - (3, 5, 8) - \end{lstlisting} - \begin{figure} - \begin{center} - \includegraphics[height=1.5in, interpolate=true]{data/array_3x5x8} - \end{center} - \end{figure} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Copies \& Views} - \vspace{-0.1in} - \begin{lstlisting} - >>> a = arange(1,9); a.shape=3,3 - >>> b = a - >>> b is a - >>> b[0,0]=0; print a - >>> c = a.view() - >>> c is a - >>> c.base is a - >>> c.flags.owndata - >>> d = a.copy() - >>> d.base is a - >>> d.flags.owndata - \end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Copies \& Views} - \vspace{-0.1in} - \begin{lstlisting} - >>> b = a[0,1:3] - >>> c = a[0::2,0::2] - >>> a.flags.owndata - >>> b.flags.owndata - >>> b.base - >>> c.base is a - \end{lstlisting} - \begin{itemize} - \item Slicing and Striding just reference the same memory - \item They produce views of the data, not copies - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Copies contd \ldots} - \begin{lstlisting} - >>> a = arange(1, 10, 2) - >>> b = a[array([0,2,3])] - >>> b.flags.owndata - >>> abool=a>5 - >>> c = a[abool] - >>> c.flags.owndata - \end{lstlisting} - \begin{itemize} - \item Indexing arrays or Boolean arrays produce copies - \end{itemize} -\inctime{15} -\end{frame} - -\section{SciPy} -\subsection{Introduction} -\begin{frame} - {Intro to SciPy} - \begin{itemize} - \item \url{http://www.scipy.org} - \item Open source scientific libraries for Python - \item Based on NumPy - \end{itemize} -\end{frame} - -\begin{frame} - \frametitle{SciPy} - \begin{itemize} - \item Provides: - \begin{itemize} - \item Linear algebra - \item Numerical integration - \item Fourier transforms - \item Signal processing - \item Special functions - \item Statistics - \item Optimization - \item Image processing - \item ODE solvers - \end{itemize} - \item Uses LAPACK, QUADPACK, ODEPACK, FFTPACK etc. from netlib - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{SciPy - Functions \& Submodules} - \begin{itemize} - \item All \typ{numpy} functions are in \typ{scipy} namespace - \item Domain specific functions organized into subpackages - \item Subpackages need to be imported separately - \end{itemize} - \begin{lstlisting} - >>> from scipy import linalg - \end{lstlisting} -\end{frame} - -\subsection{Linear Algebra} -\begin{frame}[fragile] - \frametitle{Linear Algebra} - \begin{lstlisting} - >>> import scipy as sp - >>> from scipy import linalg - >>> A = sp.array(sp.arange(1,10)) - >>> A.shape = 3,3 - >>> linalg.inv(A) - >>> linalg.det(A) - >>> linalg.norm(A) - >>> linalg.expm(A) #logm - >>> linalg.sinm(A) #cosm, tanm, ... - \end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Linear Algebra ...} - \begin{lstlisting} - >>> A = sp.array(sp.arange(1,10)) - >>> A.shape = 3,3 - >>> linalg.lu(A) - >>> linalg.eig(A) - >>> linalg.eigvals(A) - \end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Solving Linear Equations} - \vspace{-0.2in} - \begin{align*} - 3x + 2y - z & = 1 \\ - 2x - 2y + 4z & = -2 \\ - -x + \frac{1}{2}y -z & = 0 - \end{align*} - To Solve this, - \begin{lstlisting} - >>> A = sp.array([[3,2,-1],[2,-2,4] - ,[-1,1/2,-1]]) - >>> b = sp.array([1,-2,0]) - >>> x = linalg.solve(A,b) - >>> Ax = sp.dot(A,x) - >>> sp.allclose(Ax, b) - \end{lstlisting} -\inctime{15} -\end{frame} - -\subsection{Integration} -\begin{frame}[fragile] - \frametitle{Integrate} - \begin{itemize} - \item Integrating Functions given function object - \item Integrating Functions given fixed samples - \item Numerical integrators of ODE systems - \end{itemize} - Calculate the area under $(sin(x) + x^2)$ in the range $(0,1)$ - \begin{lstlisting} - >>> def f(x): - return sin(x)+x**2 - >>> integrate.quad(f, 0, 1) - \end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Integrate \ldots} - Numerically solve ODEs\\ - \begin{align*} - \frac{dx}{dt}&=-e^{-t}x^2\\ - x&=2 \quad at \ t=0 - \end{align*} - \begin{lstlisting} ->>> def dx_dt(x,t): - return -exp(-t)*x**2 ->>> t = linspace(0,2,100) ->>> x = integrate.odeint(dx_dt, 2, t) ->>> plt.plot(x,t) - \end{lstlisting} -\inctime{10} -\end{frame} - -\subsection{Interpolation} -\begin{frame}[fragile] - \frametitle{Interpolation} - \begin{lstlisting} ->>> from scipy import interpolate ->>> interpolate.interp1d? ->>> x = arange(0,2*pi,pi/4) ->>> y = sin(x) ->>> fl = interpolate.interp1d( - x,y,kind='linear') ->>> fc = interpolate.interp1d( - x,y,kind='cubic') ->>> fl(pi/3) ->>> fc(pi/3) - \end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Interpolation - Splines} - Plot the Cubic Spline of $sin(x)$ - \begin{lstlisting} ->>> tck = interpolate.splrep(x,y) ->>> xs = arange(0,2*pi,pi/50) ->>> ys = interpolate.splev(X,tck,der=0) ->>> plt.plot(x,y,'o',x,y,xs,ys) ->>> plt.show() - \end{lstlisting} -\inctime{10} -\end{frame} - -\subsection{Signal Processing} -\begin{frame}[fragile] - \frametitle{Signal \& Image Processing} - \begin{itemize} - \item Convolution - \item Filtering - \item Filter design - \item IIR filter design - \item Linear Systems - \item LTI Representations - \item Window functions - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Signal \& Image Processing} - Applying a simple median filter - \begin{lstlisting} ->>> from scipy import signal, ndimage ->>> from scipy import lena ->>> A = lena().astype('float32') ->>> B = signal.medfilt2d(A) ->>> imshow(B) - \end{lstlisting} - Zooming an array - uses spline interpolation - \begin{lstlisting} ->>> b = ndimage.zoom(A,0.5) ->>> imshow(b) ->>> b = ndimage.zoom(A,2) - \end{lstlisting} - \inctime{5} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Problems} - The Van der Pol oscillator is a type of nonconservative oscillator with nonlinear damping. It evolves in time according to the second order differential equation: - \begin{equation*} - \frac{d^2x}{dt^2}+\mu(x^2-1)\frac{dx}{dt}+x= 0 - \end{equation*} - Make a plot of $\frac{dx}{dt}$ vs. $x$. -\inctime{30} -\end{frame} -\begin{frame}{Summary} - \begin{itemize} - \item Advanced NumPy - \item SciPy - \begin{itemize} - \item Linear Algebra - \item Integration - \item Interpolation - \item Signal and Image processing - \end{itemize} - \end{itemize} -\end{frame} -\end{document} - -- Numpy arrays (30 mins) - - Matrices - - random number generation. - - Image manipulation: jigsaw puzzle. - - Monte-carlo integration. diff --git a/day2/session3.tex b/day2/session3.tex deleted file mode 100644 index d262ab5..0000000 --- a/day2/session3.tex +++ /dev/null @@ -1,498 +0,0 @@ -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% Tutorial slides on Python. -% -% Author: Prabhu Ramachandran <prabhu at aero.iitb.ac.in> -% Copyright (c) 2005-2009, Prabhu Ramachandran -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -\documentclass[compress,14pt]{beamer} -% \documentclass[handout]{beamer} -% \usepackage{pgfpages} -% \pgfpagesuselayout{4 on 1}[a4paper,border, shrink=5mm,landscape] -\usepackage{tikz} -\newcommand{\hyperlinkmovie}{} -%\usepackage{movie15} - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% Note that in presentation mode -% \paperwidth 364.19536pt -% \paperheight 273.14662pt -% h/w = 0.888 - - -\mode<presentation> -{ - \usetheme{Warsaw} - %\usetheme{Boadilla} - %\usetheme{default} - \useoutertheme{split} - \setbeamercovered{transparent} -} - -% To remove navigation symbols -\setbeamertemplate{navigation symbols}{} - -\usepackage{amsmath} -\usepackage[english]{babel} -\usepackage[latin1]{inputenc} -\usepackage{times} -\usepackage[T1]{fontenc} - -% Taken from Fernando's slides. -\usepackage{ae,aecompl} -\usepackage{mathpazo,courier,euler} -\usepackage[scaled=.95]{helvet} -\usepackage{pgf} - -\definecolor{darkgreen}{rgb}{0,0.5,0} - -\usepackage{listings} -\lstset{language=Python, - basicstyle=\ttfamily\bfseries, - commentstyle=\color{red}\itshape, - stringstyle=\color{darkgreen}, - showstringspaces=false, - keywordstyle=\color{blue}\bfseries} - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% My Macros -\setbeamercolor{postit}{bg=yellow,fg=black} -\setbeamercolor{emphbar}{bg=blue!20, fg=black} -\newcommand{\emphbar}[1] -{\begin{beamercolorbox}[rounded=true]{emphbar} - {#1} - \end{beamercolorbox} -} -%{\centerline{\fcolorbox{gray!50} {blue!10}{ -%\begin{minipage}{0.9\linewidth} -% {#1} -%\end{minipage} -% }}} - -\newcommand{\myemph}[1]{\structure{\emph{#1}}} -\newcommand{\PythonCode}[1]{\lstinline{#1}} - -\newcommand{\tvtk}{\texttt{tvtk}} -\newcommand{\mlab}{\texttt{mlab}} - -\newcounter{time} -\setcounter{time}{0} -\newcommand{\inctime}[1]{\addtocounter{time}{#1}{\vspace*{0.1in}\tiny \thetime\ m}} - -\newcommand\BackgroundPicture[1]{% - \setbeamertemplate{background}{% - \parbox[c][\paperheight]{\paperwidth}{% - \vfill \hfill - \hfill \vfill -}}} - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% Configuring the theme -%\setbeamercolor{normal text}{fg=white} -%\setbeamercolor{background canvas}{bg=black} - - - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% Title page -\title[]{3D data Visualization} - -\author[FOSSEE Team] {FOSSEE} - -\institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay} -\date[]{11, October 2009} -%\date[] % (optional) - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%\pgfdeclareimage[height=0.75cm]{iitblogo}{iitblogo} -%\logo{\pgfuseimage{iitblogo}} - -\AtBeginSection[] -{ - \begin{frame}<beamer> - \frametitle{Outline} - \tableofcontents[currentsection,currentsubsection] - \end{frame} -} - -%% Delete this, if you do not want the table of contents to pop up at -%% the beginning of each subsection: -\AtBeginSubsection[] -{ - \begin{frame}<beamer> - \frametitle{Outline} - \tableofcontents[currentsection,currentsubsection] - \end{frame} -} - -\AtBeginSection[] -{ - \begin{frame}<beamer> - \frametitle{Outline} - \tableofcontents[currentsection,currentsubsection] - \end{frame} -} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% DOCUMENT STARTS -\begin{document} - -\begin{frame} - \maketitle -\end{frame} - -\begin{frame} - \frametitle{Outline} - \tableofcontents - % You might wish to add the option [pausesections] -\end{frame} - -\section{3D Data Visualization} - -\begin{frame} - \frametitle{What is visualization?} - \Large - \begin{center} - Visual representation of data - \end{center} -\end{frame} - -\begin{frame} - \frametitle{3D visualization} - \Large - \begin{center} - Harder but important - \end{center} -\end{frame} - -\begin{frame} - \frametitle{Is this Graphics?} - \Large - \begin{center} - Visualization is about data! - \end{center} -\end{frame} - -\begin{frame} - \frametitle{Examples: trajectory in space} - \Large - \begin{center} - \pgfimage[width=2.5in]{MEDIA/m2/mlab/plot3d_ex} - \end{center} -\end{frame} - -\begin{frame} - \frametitle{Examples: Fire in a room} - \Large - \begin{center} - Demo of data - \end{center} -\inctime{10} -\end{frame} - -\section{Tools at your disposal} - -\subsection{Mayavi2} - -\begin{frame} - \frametitle{Introduction to Mayavi} - \begin{itemize} - \item Most scientists not interested in details of visualization - \item Visualization of data files with a nice UI - \item Interactive visualization of data (think Matlab) - \item Embedding visualizations in applications - \item Customization - \end{itemize} - \pause - \begin{block}{The Goal} - Provide a \alert{flexible} library/app for every one of these needs! - \end{block} -\end{frame} - -\begin{frame} - {Overview of features} - \vspace*{-0.3in} - \begin{center} - \hspace*{-0.2in}\pgfimage[width=5in]{MEDIA/m2/m2_app3_3} - \end{center} -\end{frame} - - -\begin{frame} - \frametitle{Mayavi in applications} - \vspace*{-0.3in} - \begin{center} - \hspace*{-0.2in}\pgfimage[width=4.5in]{MEDIA/m2/m2_envisage} - \end{center} -\end{frame} - -\begin{frame} - \frametitle{Live in your dialogs} - \vspace*{0.1in} - \begin{center} - \hspace*{-0.2in}\pgfimage[width=2.5in]{MEDIA/m2/mlab_tui} - \end{center} -\end{frame} - -\begin{frame} - {Exploring the documentation} - \begin{center} - \pgfimage[width=4in]{MEDIA/m2/m2_ug_doc} - \end{center} -\end{frame} - - -\begin{frame} - \frametitle{Summary} - \begin{itemize} - \item \url{http://code.enthought.com/projects/mayavi} - \item Uses VTK (\url{www.vtk.org}) - \item BSD license - \item Linux, win32 and Mac OS X - \item Highly scriptable - \item Embed in Traits UIs (wxPython and PyQt4) - \item Envisage Plugins - \item Debian/Ubuntu/Fedora - \item \alert{Pythonic} - \end{itemize} - - \inctime{10} - -\end{frame} - -\subsection{mlab} - -\begin{frame} - {Overview} - \Large - \begin{itemize} - \item Simple - \item Convenient - \item Full-featured - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - - \frametitle{Getting started} - \myemph{\Large Vanilla:} - \begin{lstlisting}[language=bash] - $ ipython -wthread - \end{lstlisting} - \myemph{\Large with Pylab:} - \begin{lstlisting}[language=bash] - $ ipython -pylab -wthread - \end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Using mlab} - - \begin{lstlisting} ->>> from enthought.mayavi import mlab - \end{lstlisting} - - \vspace*{0.5in} - - \myemph{\Large Try these} - - \vspace*{0.25in} - - \begin{lstlisting} ->>> mlab.test_<TAB> ->>> mlab.test_contour3d() ->>> mlab.test_contour3d?? - \end{lstlisting} -\end{frame} - -\begin{frame} - {Exploring the view} - \begin{columns} - \column{0.6\textwidth} - \pgfimage[width=3in]{MEDIA/m2/contour3d} - \column{0.4\textwidth} - \begin{itemize} - \item Mouse - \item Keyboard - \item Toolbar - \item Mayavi icon\pgfimage[width=0.2in]{MEDIA/m2/m2_icon} - \end{itemize} - \end{columns} -\end{frame} - -\begin{frame}[fragile] - \frametitle{\mlab\ plotting functions} - \begin{columns} - \column{0.25\textwidth} - \myemph{\Large 0D data} - \column{0.5\textwidth} - \pgfimage[width=2in]{MEDIA/m2/mlab/points3d_ex} - \end{columns} - - \begin{lstlisting} ->>> from numpy import * ->>> t = linspace(0, 2*pi, 50) ->>> u = cos(t)*pi ->>> x, y, z = sin(u), cos(u), sin(t) - \end{lstlisting} - \emphbar{\PythonCode{>>> mlab.points3d(x, y, z)}} -\end{frame} - -\begin{frame} - \begin{columns} - \column{0.25\textwidth} - \myemph{\Large 1D data} - \column{0.5\textwidth} - \pgfimage[width=2.5in]{MEDIA/m2/mlab/plot3d_ex} - \end{columns} - \emphbar{\PythonCode{>>> mlab.plot3d(x, y, z, t)}} - - Plots lines between the points - -\end{frame} - -\begin{frame}[fragile] - \begin{columns} - \column{0.25\textwidth} - \myemph{\Large 2D data} - \column{0.5\textwidth} - \pgfimage[width=2in]{MEDIA/m2/mlab/surf_ex} - \end{columns} - \begin{lstlisting} ->>> x = mgrid[-3:3:100j,-3:3:100j] ->>> z = sin(x*x + y*y) - \end{lstlisting} - - \emphbar{\PythonCode{>>> mlab.surf(x, y, z)}} - - \alert{Assumes the points are rectilinear} - -\end{frame} - -\begin{frame}[fragile] - \myemph{\Large 2D data: \texttt{mlab.mesh}} - \vspace*{0.25in} - - \emphbar{\PythonCode{>>> mlab.mesh(x, y, z)}} - - \alert{Points needn't be regular} - - \vspace*{0.25in} -\begin{lstlisting} ->>> phi, theta = numpy.mgrid[0:pi:20j, -... 0:2*pi:20j] ->>> x = sin(phi)*cos(theta) ->>> y = sin(phi)*sin(theta) ->>> z = cos(phi) ->>> mlab.mesh(x, y, z, -... representation= -... 'wireframe') -\end{lstlisting} - -\end{frame} - -\begin{frame}[fragile] - - \begin{columns} - \column{0.25\textwidth} - \myemph{\Large 3D data} - \column{0.5\textwidth} - \pgfimage[width=1.5in]{MEDIA/m2/mlab/contour3d}\\ - \end{columns} -\begin{lstlisting} ->>> x, y, z = ogrid[-5:5:64j, -... -5:5:64j, -... -5:5:64j] ->>> mlab.contour3d(x*x*0.5 + y*y + - z*z*2) -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - - \myemph{\Large 3D vector data: \PythonCode{mlab.quiver3d}} - \vspace*{0.25in} - - \pgfimage[width=2in]{MEDIA/m2/mlab/quiver3d_ex}\\ - -\begin{lstlisting} ->>> mlab.test_quiver3d() -\end{lstlisting} - -\emphbar{\PythonCode{obj = mlab.quiver3d(x, y, z, u, v, w)}} -\inctime{20} -\end{frame} - -\begin{frame} - {Getting hands dirty!} - - \begin{block}{Motivational problem} - Atmospheric data of temperature over the surface of the earth. - Let temperature ($T$) vary linearly with height ($z$): - \begin{center} - $T = 288.15 - 6.5z$ - \end{center} - \end{block} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Simple solution} - - \begin{lstlisting} -lat = linspace(-89, 89, 37) -lon = linspace(0, 360, 37) -z = linspace(0, 100, 11) - \end{lstlisting} -\pause - \begin{lstlisting} -x, y, z = mgrid[0:360:37j,-89:89:37j, - 0:100:11j] -t = 288.15 - 6.5*z -mlab.contour3d(x, y, z, t) -mlab.outline() -mlab.colorbar() - \end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Exercise: Lorenz equation} - \begin{columns} - \column{0.25\textwidth} - \begin{eqnarray*} - \frac{d x}{dt} &=& s (y-x)\\ - \frac{d y}{d t} &=& rx -y -xz\\ - \frac{d z}{d t} &=& xy - bz\\ - \end{eqnarray*} - \column{0.25\textwidth} - Let $s=10,$ - $r=28,$ - $b=8./3.$ - \end{columns} - \structure{\Large Region of interest} - \begin{lstlisting} -x, y, z = mgrid[-50:50:20j,-50:50:20j, - -10:60:20j] - \end{lstlisting} -\inctime{20} - -\end{frame} -\begin{frame}[fragile] - \frametitle{Solution} - \begin{lstlisting} -def lorenz(x,y,z,s=10.,r=28.,b=8./3.): - u = s*(y-x) - v = r*x-y-x*z - w = x*y-b*z - return u,v,w -x,y,z = mgrid [-50:50:20j,-50:50:20j, - -10:60:20j ] -u,v,w = lorenz( x , y , z ) -# Your plot here -# -mlab.show() - - \end{lstlisting} -\end{frame} - -\end{document} - diff --git a/day2/tda.tex b/day2/tda.tex deleted file mode 100644 index 7e32ef9..0000000 --- a/day2/tda.tex +++ /dev/null @@ -1,300 +0,0 @@ -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% Tutorial slides on Python. -% -% Author: Prabhu Ramachandran <prabhu at aero.iitb.ac.in> -% Copyright (c) 2005-2009, Prabhu Ramachandran -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -\documentclass[compress,14pt]{beamer} -% \documentclass[handout]{beamer} -% \usepackage{pgfpages} -% \pgfpagesuselayout{4 on 1}[a4paper,border, shrink=5mm,landscape] -\usepackage{tikz} -\newcommand{\hyperlinkmovie}{} -%\usepackage{movie15} - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% Note that in presentation mode -% \paperwidth 364.19536pt -% \paperheight 273.14662pt -% h/w = 0.888 - - -\mode<presentation> -{ - \usetheme{Warsaw} - %\usetheme{Boadilla} - %\usetheme{default} - \useoutertheme{split} - \setbeamercovered{transparent} -} - -% To remove navigation symbols -\setbeamertemplate{navigation symbols}{} - -\usepackage{amsmath} -\usepackage[english]{babel} -\usepackage[latin1]{inputenc} -\usepackage{times} -\usepackage[T1]{fontenc} - -% Taken from Fernando's slides. -\usepackage{ae,aecompl} -\usepackage{mathpazo,courier,euler} -\usepackage[scaled=.95]{helvet} -\usepackage{pgf} - -\definecolor{darkgreen}{rgb}{0,0.5,0} - -\usepackage{listings} -\lstset{language=Python, - basicstyle=\ttfamily\bfseries, - commentstyle=\color{red}\itshape, - stringstyle=\color{darkgreen}, - showstringspaces=false, - keywordstyle=\color{blue}\bfseries} - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% My Macros -\setbeamercolor{postit}{bg=yellow,fg=black} -\setbeamercolor{emphbar}{bg=blue!20, fg=black} -\newcommand{\emphbar}[1] -{\begin{beamercolorbox}[rounded=true]{emphbar} - {#1} - \end{beamercolorbox} -} -%{\centerline{\fcolorbox{gray!50} {blue!10}{ -%\begin{minipage}{0.9\linewidth} -% {#1} -%\end{minipage} -% }}} - -\newcommand{\myemph}[1]{\structure{\emph{#1}}} -\newcommand{\PythonCode}[1]{\lstinline{#1}} - -\newcommand{\tvtk}{\texttt{tvtk}} -\newcommand{\mlab}{\texttt{mlab}} - -\newcounter{time} -\setcounter{time}{0} -\newcommand{\inctime}[1]{\addtocounter{time}{#1}{\vspace*{0.1in}\tiny \thetime\ m}} - -\newcommand\BackgroundPicture[1]{% - \setbeamertemplate{background}{% - \parbox[c][\paperheight]{\paperwidth}{% - \vfill \hfill - \hfill \vfill -}}} - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% Configuring the theme -%\setbeamercolor{normal text}{fg=white} -%\setbeamercolor{background canvas}{bg=black} - - - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% Title page -\title[]{Test Driven Approach} - -\author[FOSSEE Team] {FOSSEE} - -\institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay} -\date[] {11, October 2009} -\date[] % (optional) - -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% - -%\pgfdeclareimage[height=0.75cm]{iitblogo}{iitblogo} -%\logo{\pgfuseimage{iitblogo}} - -\AtBeginSection[] -{ - \begin{frame}<beamer> - \frametitle{Outline} - \Large - \tableofcontents[currentsection,currentsubsection] - \end{frame} -} - -%% Delete this, if you do not want the table of contents to pop up at -%% the beginning of each subsection: -\AtBeginSubsection[] -{ - \begin{frame}<beamer> - \frametitle{Outline} - \tableofcontents[currentsection,currentsubsection] - \end{frame} -} - -\AtBeginSection[] -{ - \begin{frame}<beamer> - \frametitle{Outline} - \tableofcontents[currentsection,currentsubsection] - \end{frame} -} -%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% -% DOCUMENT STARTS -\begin{document} - -\begin{frame} - \maketitle -\end{frame} - -\section{Test Driven Approach} - -\begin{frame} - \frametitle{Testing code with nosetests} - - \begin{itemize} - \item Writing tests is really simple! - - \item Using nose. - - \item Example! - \end{itemize} -\end{frame} - -\begin{frame} - \frametitle{Need of Testing!} - - \begin{itemize} - \item Quality - - \item Regression - - \item Documentation - \end{itemize} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Nosetest} - \begin{lstlisting} -def gcd(a, b): - """Returns gcd of a and b, - handles only positive numbers.""" - if a%b == 0: return b - return gcd(b, a%b) -def lcm(a, b): - return a*b/gcd(a, b) - -if __name__ == '__main__': - import nose - nose.main() - \end{lstlisting} -\inctime{10} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Example} - \begin{block}{Problem Statement:} - Write a function to check whether a given input - string is a palindrome. - \end{block} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Function: palindrome.py} -\begin{lstlisting} -def is_palindrome(input_str): - return input_str == input_str[::-1] -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Test for the palindrome: palindrome.py} -\begin{lstlisting} -from plaindrome import is_palindrome -def test_function_normal_words(): - input = "noon" - assert is_palindrome(input) == True -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Running the tests.} -\begin{lstlisting} -$ nosetests test.py -. ----------------------------------------------- -Ran 1 test in 0.001s - -OK -\end{lstlisting} -\end{frame} - -\begin{frame}[fragile] - \frametitle{Exercise: Including new tests.} -\begin{lstlisting} -def test_function_ignore_cases_words(): - input = "Noon" - assert is_palindrome(input) == True -\end{lstlisting} - \vspace*{0.25in} - Check\\ - \PythonCode{$ nosetests test.py} \\ - \begin{block}{Task} - Tweak the code to pass this test. - \end{block} -\end{frame} - -%\begin{frame}[fragile] -% \frametitle{Lets write some test!} -%\begin{lstlisting} -%#for form of equation y=mx+c -%#given m and c for two equation, -%#finding the intersection point. -%def intersect(m1,c1,m2,c2): -% x = (c2-c1)/(m1-m2) -% y = m1*x+c1 -% return (x,y) -%\end{lstlisting} -% -%Create a simple test for this -% -%function which will make it fail. -% -%\inctime{15} -%\end{frame} -% - -\begin{frame}[fragile] - \frametitle{Exercise} - Based on Euclid's algorithm: - $gcd(a,b)=gcd(b,b\%a)$\\ - gcd function can be written as: - \begin{lstlisting} - def gcd(a, b): - if a%b == 0: return b - return gcd(b, a%b) - \end{lstlisting} - \vspace*{-0.15in} - \begin{block}{Task} - \begin{itemize} - \item Write at least - two tests for above mentioned function. - \item Write a non recursive implementation - of gcd(), and test it using already - written tests. - \end{itemize} - \end{block} - -\inctime{15} -\end{frame} - -\begin{frame}{In this session we have covered:} - \begin{itemize} - \item Need for visualization. - \item Tools available. - \item How to follow Test Driven Approach. - \end{itemize} -\end{frame} -\begin{frame} - \begin{center} - \Huge - Thank you! - \end{center} -\end{frame} - -\end{document} |