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#+LaTeX_CLASS: beamer
#+LaTeX_CLASS_OPTIONS: [presentation]
#+BEAMER_FRAME_LEVEL: 1
#+BEAMER_HEADER_EXTRA: \usetheme{Warsaw}\usecolortheme{default}\useoutertheme{infolines}\setbeamercovered{transparent}
#+COLUMNS: %45ITEM %10BEAMER_env(Env) %10BEAMER_envargs(Env Args) %4BEAMER_col(Col) %8BEAMER_extra(Extra)
#+PROPERTY: BEAMER_col_ALL 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0 :ETC
#+LaTeX_CLASS: beamer
#+LaTeX_CLASS_OPTIONS: [presentation]
#+LaTeX_HEADER: \usepackage[english]{babel} \usepackage{ae,aecompl}
#+LaTeX_HEADER: \usepackage{mathpazo,courier,euler} \usepackage[scaled=.95]{helvet}
#+LaTeX_HEADER: \usepackage{listings}
#+LaTeX_HEADER:\lstset{language=Python, basicstyle=\ttfamily\bfseries,
#+LaTeX_HEADER: commentstyle=\color{red}\itshape, stringstyle=\color{darkgreen},
#+LaTeX_HEADER: showstringspaces=false, keywordstyle=\color{blue}\bfseries}
#+TITLE:
#+AUTHOR: FOSSEE
#+EMAIL:
#+DATE:
#+DESCRIPTION:
#+KEYWORDS:
#+LANGUAGE: en
#+OPTIONS: H:3 num:nil toc:nil \n:nil @:t ::t |:t ^:t -:t f:t *:t <:t
#+OPTIONS: TeX:t LaTeX:nil skip:nil d:nil todo:nil pri:nil tags:not-in-toc
*
#+begin_latex
\begin{center}
\vspace{12pt}
\textcolor{blue}{\huge Advanced features of Functions}
\end{center}
\vspace{18pt}
\begin{center}
\vspace{10pt}
\includegraphics[scale=0.95]{../images/fossee-logo.png}\\
\vspace{5pt}
\scriptsize Developed by FOSSEE Team, IIT-Bombay. \\
\scriptsize Funded by National Mission on Education through ICT\\
\scriptsize MHRD,Govt. of India\\
\includegraphics[scale=0.30]{../images/iitb-logo.png}\\
\end{center}
#+end_latex
* Objectives
At the end of this tutorial, you will be able to,
- Assign default values to arguments, when defining functions.
- Define and call functions with keyword arguments.
- Learn some of the built-in functions available in Python standard
library and the scientific computing libraries.
* Pre-requisite
Spoken tutorial on -
- Getting started with functions
* Functions
#+begin_src Python
s.strip() # strips on spaces.
s.strip('@') # strips the string of '@' symbols.
plot(x, y) # plots with x vs. y using default line style.
plot(x, y, 'o') # plots x vs. y with circle markers.
linspace(0, 2*pi, 100) # returns 100 points between 0 and 2pi
linspace(0, 2*pi) # returns 50 points between 0 and 2pi
#+end_src
* Exercise 1
- Redefine the function ~welcome~, by interchanging it's
arguments.
Place the ~name~ argument with it's default value of
"World" before the ~greet~ argument.
* Solution 1
#+begin_src python
def welcome(name="World", greet):
print greet, name
#+end_src
We get an error that reads ~SyntaxError: non-default argument follows
default argument~. When defining a function all the
argument with default values should come at the end.
* Exercise 2
- See the definition of linspace using ~?~ and make a note of all the
arguments with default values are towards the end.
* Exercise 3
- Redefine the function ~welcome~ with a default value of
"Hello" to the ~greet~ argument.
Then, call the function without any arguments.
* Keyword arguments examples
#+begin_src Python
legend(['sin(2y)'], loc = 'center')
plot(y, sin(y), 'g', linewidth = 2)
annotate('local max', xy = (1.5, 1))
pie(science.values(), labels = science.keys())
#+end_src
* Built-in functions
#+begin_src Python
Math functions - abs, sin, ....
Plot functions - plot, bar, pie ...
Boolean functions - and, or, not ...
#+end_src
* Classes of functions
#+begin_src Python
- pylab
- plot, bar, contour, boxplot, errorbar, log, polar, quiver, semilog
- scipy (modules)
- fftpack, stats, linalg, ndimage, signal, optimize, integrate
#+end_src
* Summary
In this tutorial, we have learnt to,
- Define functions with default arguments.
- Call functions using keyword arguments.
- Use the range of functions available in the Python standard library
and the Scientific Computing related packages.
* Evaluation
1. All arguments of a function cannot have default values.
- True or False?
2. The following is a valid function definition. True or False?
#+begin_src Python
def seperator(count=40, char, show=False):
if show:
print char * count
return char * count
#+end_src
3. When calling a function,
- the arguments should always be in the order in which they are defined.
- only keyword arguments can be in any order, but should be called
at the beginning.
- only keyword arguments can be in any order, but should be called
at the end.
* Solutions
1. False
2. False
3. only keyword arguments can be in any order,
but should be called at the end
*
#+begin_latex
\begin{block}{}
\begin{center}
\textcolor{blue}{\Large THANK YOU!}
\end{center}
\end{block}
\begin{block}{}
\begin{center}
For more Information, visit our website\\
\url{http://fossee.in/}
\end{center}
\end{block}
#+end_latex
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