196 

   197 \subsection{mlab}

   198 

   199 \begin{frame}

   200     {Overview}

   201     \Large

   202     \begin{itemize}

   203         \item Simple

   204         \item Convenient

   205         \item Full-featured

   206     \end{itemize}

   207 \end{frame}

   208 

   209 \begin{frame}[fragile]

   210 

   211     \frametitle{Getting started}

   212     \myemph{\Large Vanilla:}

   213     \begin{lstlisting}[language=bash]

   214         $ ipython -wthread

   215     \end{lstlisting}

   216     \myemph{\Large with Pylab:}

   217     \begin{lstlisting}[language=bash]

   218         $ ipython -pylab -wthread

   219     \end{lstlisting}

   220 \end{frame}

   221 

   222 \begin{frame}[fragile]

   223     \frametitle{Using mlab:}

   224 

   225     \begin{lstlisting}

   226 >>> from enthought.mayavi import mlab

   227     \end{lstlisting}

   228 

   229     \vspace*{0.5in}

   230 

   231     \myemph{\Large Try these:}

   232 

   233     \vspace*{0.25in}

   234 

   235     \begin{lstlisting}

   236 >>> mlab.test_<TAB>

   237 >>> mlab.test_contour3d()

   238 >>> mlab.test_contour3d??

   239     \end{lstlisting}

   240 \end{frame}

   241 

   242 \begin{frame}

   243     {Exploring the view}

   244     \begin{columns}

   245         \column{0.6\textwidth}

   246     \pgfimage[width=3in]{MEDIA/m2/contour3d}

   247         \column{0.4\textwidth}

   248         \begin{itemize}

   249             \item Mouse

   250             \item Keyboard

   251             \item Toolbar

   252             \item Mayavi icon(wait for it...) \pgfimage[width=0.2in]{MEDIA/m2/m2_icon}

   253         \end{itemize}

   254     \end{columns}

   255 \end{frame}

   256 

   257 \begin{frame}[fragile]

   258     \frametitle{\mlab\ plotting functions}

   259     \begin{columns}

   260         \column{0.25\textwidth}

   261         \myemph{\Large 0D data}

   262         \column{0.5\textwidth}

   263     \pgfimage[width=2in]{MEDIA/m2/mlab/points3d_ex}

   264     \end{columns}

   265 

   266     \begin{lstlisting}

   267 >>> from numpy import *

   268 >>> t = linspace(0, 2*pi, 50)

   269 >>> u = cos(t)*pi

   270 >>> x, y, z = sin(u), cos(u), sin(t)

   271     \end{lstlisting}

   272     \emphbar{\PythonCode{>>> mlab.points3d(x, y, z)}}

   273 \end{frame}

   274 

   275 \begin{frame}

   276   \begin{columns}

   277         \column{0.25\textwidth}

   278         \myemph{\Large 1D data}

   279         \column{0.5\textwidth}

   280         \pgfimage[width=2.5in]{MEDIA/m2/mlab/plot3d_ex}

   281   \end{columns}

   282   \emphbar{\PythonCode{>>> mlab.plot3d(x, y, z, t)}}

   283 

   284     Plots lines between the points

   285     

   286 \end{frame}

   287 

   288 \begin{frame}[fragile]

   289     \begin{columns}

   290         \column{0.25\textwidth}

   291         \myemph{\Large 2D data}

   292         \column{0.5\textwidth}

   293         \pgfimage[width=2in]{MEDIA/m2/mlab/surf_ex}

   294     \end{columns}            

   295     \begin{lstlisting}

   296 >>> x = mgrid[-3:3:100j,-3:3:100j]

   297 >>> z = sin(x*x + y*y)

   298     \end{lstlisting}

   299 

   300     \emphbar{\PythonCode{>>> mlab.surf(x, y, z)}}

   301 

   302     \alert{Assumes the points are rectilinear}

   303 

   304 \end{frame}

   305 

   306 \begin{frame}[fragile]

   307     \myemph{\Large 2D data: \texttt{mlab.mesh}}

   308     \vspace*{0.25in}

   309 

   310     \emphbar{\PythonCode{>>> mlab.mesh(x, y, z)}}

   311 

   312     \alert{Points needn't be regular}

   313 

   314     \vspace*{0.25in}

   315 \begin{lstlisting}

   316 >>> phi, theta = numpy.mgrid[0:pi:20j, 

   317 ...                         0:2*pi:20j]

   318 >>> x = sin(phi)*cos(theta)

   319 >>> y = sin(phi)*sin(theta)

   320 >>> z = cos(phi)

   321 >>> mlab.mesh(x, y, z, 

   322 ...           representation='wireframe')

   323 \end{lstlisting}

   324 

   325 \end{frame}

   326 

   327 \begin{frame}[fragile]

   328 

   329   \begin{columns}

   330         \column{0.25\textwidth}

   331         \myemph{\Large 3D data}

   332         \column{0.5\textwidth}

   333         \pgfimage[width=1.5in]{MEDIA/m2/mlab/contour3d}\\        

   334     \end{columns}

   335 \begin{lstlisting}

   336 >>> x, y, z = ogrid[-5:5:64j, 

   337 ...                -5:5:64j, 

   338 ...                -5:5:64j]

   339 >>> mlab.contour3d(x*x*0.5 + y*y + 

   340                    z*z*2)

   341 \end{lstlisting}

   342 \end{frame}

   343 

   344 \begin{frame}[fragile]

   345 

   346     \myemph{\Large 3D vector data: \PythonCode{mlab.quiver3d}}

   347     \vspace*{0.25in}

   348 

   349     \pgfimage[width=2in]{MEDIA/m2/mlab/quiver3d_ex}\\

   350     

   351 \begin{lstlisting}

   352 >>> mlab.test_quiver3d()

   353 \end{lstlisting}

   354 

   355 \emphbar{\PythonCode{obj = mlab.quiver3d(x, y, z, u, v, w)}}

   356 \inctime{20}

   357 \end{frame}

   471 

   472 \section{Test Driven Approach}

   473 

   474 \begin{frame}

   475     \frametitle{Testing code with \typ{nosetests}}

   476    

   477     \begin{itemize}

   478         \item Writing tests is really simple!

   479 

   480         \item Using nose.

   481 

   482         \item Example!

   483     \end{itemize}

   484 \end{frame}

   485 

   486 \begin{frame}

   487     \frametitle{Need of Testing!}

   488    

   489     \begin{itemize}

   490         \item Quality

   491 

   492         \item Regression

   493 

   494         \item Documentation

   495     \end{itemize}

   496 \end{frame}

   497 

   498 \begin{frame}[fragile]

   499     \frametitle{Nosetest}

   500   \begin{lstlisting}

   501 def gcd(a, b):

   502     """Returns gcd of a and b, 

   503      handles only positive numbers."""

   504     if a%b == 0: return b

   505     return gcd(b, a%b)

   506 def lcm(a, b):

   507     return a*b/gcd(a, b)

   508 

   509 if __name__ == '__main__':

   510     import nose

   511     nose.main()

   512   \end{lstlisting}

   513 \inctime{10}

   514 \end{frame}

   515 

   516 \begin{frame}[fragile]

   517     \frametitle{Example}

   518     \begin{block}{Problem Statement:}

   519       Write a function to check whether a given input

   520       string is a palindrome.

   521     \end{block}

   522 \end{frame}

   523 

   524 \begin{frame}[fragile]

   525     \frametitle{Function: code.py}

   526 \begin{lstlisting}    

   527 def is_palindrome(input_str):

   528   return input_str == input_str[::-1]

   529 \end{lstlisting}    

   530 \end{frame}

   531 

   532 \begin{frame}[fragile]

   533     \frametitle{Test for the palindrome: code.py}

   534 \begin{lstlisting}    

   535 from code import is_palindrome

   536 def test_function_normal_words():

   537   input = "noon"

   538   assert is_palindrome(input) == True

   539 \end{lstlisting}    

   540 \end{frame}

   541 

   542 \begin{frame}[fragile]

   543     \frametitle{Running the tests.}

   544 \begin{lstlisting}    

   545 $ nosetests test.py 

   546 .

   547 ----------------------------------------------

   548 Ran 1 test in 0.001s

   549 

   550 OK

   551 \end{lstlisting}    

   552 \end{frame}

   553 

   554 \begin{frame}[fragile]

   555     \frametitle{Exercise: Including new tests.}

   556 \begin{lstlisting}    

   557 def test_function_ignore_cases_words():

   558   input = "Noon"

   559   assert is_palindrome(input) == True

   560 \end{lstlisting}

   561 Check

   562 

   563 \PythonCode{$ nosetests test.py} 

   564 

   565 Tweak the code to pass this test.

   566 \end{frame}

   567 

   568 \begin{frame}[fragile]

   569     \frametitle{Lets write some test!}

   570 \begin{lstlisting}    

   571 #for form of equation y=mx+c

   572 #given m and c for two equation,

   573 #finding the intersection point.

   574 def intersect(m1,c1,m2,c2):

   575     x = (c2-c1)/(m1-m2)

   576     y = m1*x+c1

   577     return (x,y)

   578 \end{lstlisting}

   579 

   580 Create a simple test for this

   581 

   582 function which will make it fail.

   583 

   584 \inctime{15} 

   585 \end{frame}

   586 

   587 \section{Summary}

   588 \begin{frame}{So we have covered:}

   589   \begin{itemize}

   590     \item Need for vizualization.

   591     \item Tools available.

   592     \item How to follow Test Driven Approach.

   593   \end{itemize}

   594 \end{frame}

   595 \begin{frame}

   596     \begin{center}

   597         \Huge    

   598         Thank you!

   599     \end{center}

   600 \end{frame}