%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %Tutorial slides on Python. % % Author: FOSSEE % Copyright (c) 2009, FOSSEE, IIT Bombay %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% \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 { \usetheme{Warsaw} \useoutertheme{infolines} \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[Interactive Plotting]{Python for Science and Engg: Interactive Plotting} \author[FOSSEE] {FOSSEE} \institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay} \date[] {Day 1, Session 1} %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %\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} \frametitle{Outline} \tableofcontents[currentsection,currentsubsection] \end{frame} } \AtBeginSection[] { \begin{frame} \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} %% \begin{frame} %% \frametitle{Outline} %% \tableofcontents %% % You might wish to add the option [pausesections] %% \end{frame} \begin{frame} \frametitle{Tutorial Schedule: Day 1} \begin{description} \item[Session 1] 08:00--9:00 \item[Session 2] 9:00--10:00 \item[Coffee] 10:00--10:20 \item[Session 3] 10:20--11:20 \item[Session 4] 11:20--12:20 \item[Lunch] 12:20--13:40 \item[Quiz 1] 13:40--13:55 \item[Exercises] 14:00--14:40 \item[Session 5] 14:40--15:40 \item[Coffee] 15:40--16:00 \item[Quiz 2] 16:00--16:15 \item[Session 6] 16:15--17:00 \item[Session 7] 17:00-18:00 \end{description} \end{frame} \begin{frame} \frametitle{Tutorial Schedule: Day 2} \begin{description} \item[Session 1] 08:00--9:00 \item[Session 2] 9:00--10:00 \item[Coffee] 10:00--10:20 \item[Quiz 3] 10:20--10:35 \item[Exercises] 10:35--11:30 \item[Session 3] 11:30--12:20 \end{description} \end{frame} \section{Checklist} \begin{frame} \frametitle{Checklist} \begin{enumerate} \item IPython \item Editor - we recommend \alert{scite} \item Data files: \begin{itemize} \item \typ{sslc1.txt} \item \typ{pendulum.txt} \item \typ{pos.txt} \item \typ{holmes.txt} \item \typ{anag.txt} \end{itemize} \item Python scripts: \begin{itemize} \item \typ{sslc_allreg.py} \item \typ{sslc_science.py} \end{itemize} \item Images \begin{itemize} \item \typ{lena.png} \item \typ{smoothing.gif} \end{itemize} \end{enumerate} \end{frame} \begin{frame} \frametitle{About the Workshop} \begin{block}{Intended Audience} \begin{itemize} \item Engg., Mathematics and Science teachers. \item Interested students from similar streams. \end{itemize} \end{block} \begin{block}{Goal: Successful participants will be able to} \begin{itemize} \item Use Python as plotting, computational tool. \item Understand how to use Python as a scripting and problem solving language. \item Train students for the same. \end{itemize} \end{block} \end{frame} %% \begin{frame}[fragile] %% \frametitle{The Python interpreter \ldots} %% \begin{block}{} %% \begin{lstlisting} %% $ python %% \end{lstlisting} %$ %% \end{block} %% \begin{lstlisting} %% >>> print "Hello, World!" %% Hello, World! %% \end{lstlisting} %% Exiting %% \begin{lstlisting} %% >>> ^D(Ctrl-D) %% $ %% \end{lstlisting} %$ %% \end{frame} \section{Starting up Ipython} \begin{frame}[fragile] \frametitle{Starting up \ldots} \begin{block}{} \begin{lstlisting} $ ipython -pylab \end{lstlisting} %$ \end{block} \begin{lstlisting} In []: print "Hello, World!" Hello, World! \end{lstlisting} Exiting \begin{lstlisting} In []: ^D(Ctrl-D) Do you really want to exit([y]/n)? y \end{lstlisting} An alternative to IPython is bpython \end{frame} %% \section{Ipython with magic} %% \begin{frame}[fragile] %% \frametitle{Let the magic begin \ldots} %% \begin{itemize} %% \item \alert{IPython is an improved interpreter}\\ %% \item \alert{Recommended for Scientific and Computing work}\\ %% \end{itemize} %% \begin{block}{} %% \begin{lstlisting} %% $ ipython -pylab %% \end{lstlisting} %$ %% \end{block} %% \end{frame} \section{Loops} \begin{frame}[fragile] \frametitle{Loops} Breaking out of loops \begin{lstlisting} In []: while True: ...: print "Hello, World!" ...: Hello, World! Hello, World!^C(Ctrl-C) ------------------------------------ KeyboardInterrupt \end{lstlisting} \end{frame} \section{Plotting} \subsection{Drawing plots} \begin{frame}[fragile] \frametitle{First Plot} \begin{columns} \column{0.25\textwidth} \hspace*{-0.5in} \includegraphics[height=2in, interpolate=true]{data/firstplot} \column{0.8\textwidth} \begin{block}{} \begin{small} \begin{lstlisting} In []: x = linspace(0, 2*pi, 50) In []: plot(x, sin(x)) \end{lstlisting} \end{small} \end{block} \end{columns} \end{frame} \begin{frame}[fragile] \frametitle{Walkthrough} \begin{block}{\typ{x = linspace(start, stop, num)} } returns \typ{num} evenly spaced points, in the interval [\typ{start}, \typ{stop}]. \end{block} \begin{lstlisting} x[0] = start x[num - 1] = end \end{lstlisting} \vspace*{.35in} \begin{block}{\typ{plot(x, y)}} plots \typ{x} and \typ{y} using default line style and color \end{block} %\inctime{10} \end{frame} \subsection{Decoration} \begin{frame}[fragile] \frametitle{Adding Labels} \begin{columns} \column{0.25\textwidth} \hspace*{-0.45in} \includegraphics[height=2in, interpolate=true]{data/label} \hspace*{0.5in} \column{0.55\textwidth} \begin{block}{} \small \begin{lstlisting} In []: xlabel('x') In []: ylabel('sin(x)') \end{lstlisting} \small % \end{lstlisting} %\typ{xlabel(s)} sets the label of the \typ{x}-axis to \typ{s} % \begin{lstlisting} \end{block} %\typ{ylabel(s)} sets the label of the \typ{y}-axis to \typ{s} \end{columns} \end{frame} \begin{frame}[fragile] \frametitle{Another example} \begin{lstlisting} In []: clf() \end{lstlisting} \emphbar{Clears the plot area.} \begin{lstlisting} In []: y = linspace(0, 2*pi, 50) In []: plot(y, sin(2*y)) In []: xlabel('y') In []: ylabel('sin(2y)') \end{lstlisting} \end{frame} \subsection{More decoration} \begin{frame}[fragile] \frametitle{Title and Legends} \vspace*{-0.15in} % \begin{block}{} % \small \begin{lstlisting} In []: title('Sinusoids') In []: legend(['sin(2y)']) \end{lstlisting} % \small % \end{block} \vspace*{-0.1in} \begin{center} \includegraphics[height=2in, interpolate=true]{data/legend} \end{center} \end{frame} \begin{frame}[fragile] \frametitle{Legend Placement} \begin{block}{} \small \begin{lstlisting} In []: legend(['sin(2y)'], loc = 'center') \end{lstlisting} \end{block} \begin{columns} \column{0.6\textwidth} \includegraphics[height=2in, interpolate=true]{data/position} \column{0.45\textwidth} \vspace{-0.2in} \begin{lstlisting} 'best' 'right' 'center' \end{lstlisting} \end{columns} \end{frame} %% \begin{frame}[fragile] %% \frametitle{For arbitrary location} %% \vspace*{-0.1in} %% \begin{lstlisting} %% In []: legend(['sin(2y)'], loc=(.8,.1)) %% \end{lstlisting} %% \emphbar{Specify south-east corner position} %% %\vspace*{-0.2in} %% \begin{center} %% \includegraphics[height=2in, interpolate=true]{data/loc} %% \end{center} %% %\inctime{10} %% \end{frame} \begin{frame}[fragile] \frametitle{Saving \& Closing} \begin{lstlisting} In []: savefig('sin.png') In []: close() \end{lstlisting} Supported formats to store images: \begin{itemize} \item png \item eps - Easy to embed in LaTeX files \item emf \item pdf \item ps \item raw \item rgba \item svg \end{itemize} \end{frame} \section{Multiple plots} \begin{frame}[fragile] \frametitle{Overlaid Plots} \begin{lstlisting} In []: clf() In []: plot(y, sin(y)) In []: plot(y, cos(y)) In []: xlabel('y') In []: ylabel('f(y)') In []: legend(['sin(y)', 'cos(y)']) \end{lstlisting} \emphbar{By default plots would be overlaid!} \end{frame} \begin{frame}[fragile] \frametitle{Plotting separate figures} \begin{lstlisting} In []: clf() In []: figure(1) In []: plot(y, sin(y)) In []: figure(2) In []: plot(y, cos(y)) In []: savefig('cosine.png') In []: figure(1) In []: title('sin(y)') In []: savefig('sine.png') In []: close() In []: close() \end{lstlisting} \end{frame} \begin{frame}[fragile] \frametitle{Showing it better} \vspace{-0.15in} \begin{lstlisting} In []: plot(y, cos(y), 'r') In []: clf() In []: plot(y, sin(y), 'g', linewidth=2) \end{lstlisting} \vspace*{-0.2in} \begin{center} \includegraphics[height=2.2in, interpolate=true]{data/green} \end{center} %\inctime{10} \end{frame} \begin{frame}[fragile] \frametitle{Annotating} \vspace*{-0.15in} \begin{lstlisting} In []: annotate('local max', xy=(1.5, 1)) \end{lstlisting} \vspace*{-0.2in} \begin{center} \includegraphics[height=2in, interpolate=true]{data/annotate} \end{center} \end{frame} \begin{frame}[fragile] \frametitle{Axes lengths} \emphbar{Getting axes lengths} \begin{lstlisting} In []: xmin, xmax = xlim() In []: ymin, ymax = ylim() \end{lstlisting} \emphbar{Set the axes limits} \begin{lstlisting} In []: xlim(xmin, 2*pi ) In []: ylim(ymin-0.2, ymax+0.2) \end{lstlisting} \end{frame} \begin{frame}[fragile] \frametitle{Axes lengths} \begin{center} \includegraphics[height=3in, interpolate=true]{data/limits} \end{center} \end{frame} \begin{frame}[fragile] \frametitle{Review Problem} \begin{enumerate} \item Plot x, -x, sin(x), xsin(x) in range $-5\pi$ to $5\pi$ \item Add a legend \item Annotate the origin \item Set axes limits to the range of x \end{enumerate} \vspace*{-0.1in} \begin{center} \includegraphics[height=2.1in, interpolate=true]{data/four_plot} \end{center} \end{frame} \begin{frame}[fragile] \frametitle{Review Problem \ldots} \alert{Plotting \ldots} \begin{lstlisting} In []: x=linspace(-5*pi, 5*pi, 500) In []: plot(x, x, 'b') In []: plot(x, -x, 'b') In []: plot(x, sin(x), 'g', linewidth=2) In []: plot(x, x*sin(x), 'r', linewidth=3) \end{lstlisting} $\vdots$ \end{frame} \begin{frame}[fragile] \frametitle{Review Problem \ldots} \alert{Legend \& Annotation\ldots} \begin{lstlisting} In []: legend(['x', '-x', 'sin(x)', 'xsin(x)']) In []: annotate('origin', xy = (0, 0)) \end{lstlisting} \alert{Setting Axes limits\ldots} \begin{lstlisting} In []: xlim(-5*pi, 5*pi) In []: ylim(-5*pi, 5*pi) \end{lstlisting} \end{frame} \begin{frame}[fragile] \frametitle{Command History} Use the \typ{\%hist} \alert{magic} command of IPython \typ{In []: \%hist}\\ This displays all the commands typed in so far aka Command History. \begin{block}{Careful about errors!} \kwrd{\%hist} will contain the errors as well.\\ \end{block} \begin{block}{Magic Commands?} Magic commands are commands provided by IPython to make our life easier. \end{block} \end{frame} \begin{frame}[fragile] \frametitle{Saving commands into script} Use the \typ{\%save} \alert{magic} command of IPython \begin{block}{} \typ{\%save script_name line_numbers} \end{block} Line numbers can be specified individually separated by commas or as a range separated by a dash.\\ \begin{block}{} \typ{\%save four_plot.py} \alert{\typ{ 16 18-27}} \\ \end{block} This saves from the history the commands entered on line numbers \alert{16, 18, 19, 20, \ldots 27} \end{frame} \begin{frame} \frametitle{Python Scripts\ldots} Now, four\_plot.py is called a Python Script. \begin{itemize} \item run the script in IPython using \typ{\%run four_plot.py}\\ \end{itemize} \pause \alert{\typ{NameError: name 'linspace' is not defined}} \begin{block}{} To avoid this, run using \alert{\typ{\%run -i four_plot.py}}\\ \end{block} \end{frame} \begin{frame}[fragile] \frametitle{Result graph} \begin{center} \includegraphics[height=3in, interpolate=true]{data/four_plot} \end{center} \end{frame} \begin{frame}[fragile] \frametitle{What did we learn?} \begin{itemize} \item Starting up IPython \item Creating simple plots. \item Adding labels and legends. \item Annotating plots. \item Changing the looks: size, linewidth \item \kwrd{\%hist} - History of commands \item \kwrd{\%save} - Saving commands \item Running a script using \kwrd{\%run -i} \end{itemize} \end{frame} \end{document} %% Questions for Quiz %% %% ------------------ %% \begin{frame}[fragile] \frametitle{\incqno } Draw (roughly) the plot obtained by the following: \begin{lstlisting} In []: x = linspace(0, pi, 3) In []: plot(x, sin(x)) \end{lstlisting} \end{frame} \begin{frame}[fragile] \frametitle{\incqno } Describe the plot produced by the following: \begin{lstlisting} In []: x = linspace(0, 2*pi, 50) In []: plot(x, cos(x), 'go') \end{lstlisting} \end{frame} \begin{frame} \frametitle{\incqno } How will you plot the previous graph with line width set to 3? How will you set the $x$ and $y$ labels of the plot? \end{frame} \begin{frame} \frametitle{\incqno } How will you set the x and y axis limits so that the region of interest is in the rectangle $(0, -1.5)$ (left bottom coordinate) and $(2\pi, 1.5)$ (right top coordinate)? \end{frame} \begin{frame} \frametitle{\incqno } What ipython magic command do you use to obtain the lines of code you have already typed in the interpreter? What command do you use to save them? \end{frame} \begin{frame}[fragile] \frametitle{\incqno } The following code snippet has an error/bug: \begin{lstlisting} In []: y = linspace(0, 2*pi, 50) In []: plot(y, sin(y)) In []: clf() In []: plot(y, cos(y)) In []: legend(['sin(y)', 'cos(y)']) \end{lstlisting} What is the error? How do you fix it? \end{frame}