Merged with mainline.

5 files changed, 684 insertions, 230 deletions

diff --git a/day2/DebugginDiagram.png b/day2/DebugginDiagram.png
new file mode 100644
index 0000000..41af377
--- /dev/null
+++ b/day2/DebugginDiagram.png
diff --git a/day2/session1.tex b/day2/session1.tex
index 18feb02..5fb42e0 100644
--- a/day2/session1.tex
+++ b/day2/session1.tex
@@ -140,13 +140,13 @@
   \begin{itemize}
     \item \kwrd{int}\\ Any whole number is an \kwrd{int}, no matter what the size!
   \begin{lstlisting}
-In []: a = 13
+In [1]: a = 13
 
-In []: a = 99999999999999999999
+In [2]: b = 99999999999999999999
   \end{lstlisting}
     \item \kwrd{float}
   \begin{lstlisting}
-In []: fl = 3.141592
+In [3]: fl = 3.141592
   \end{lstlisting}
   \end{itemize}
 \end{frame}
@@ -154,101 +154,254 @@ In []: fl = 3.141592
 \begin{frame}[fragile]
 \frametitle{Complex numbers}
   \begin{lstlisting}
-In []: cplx = 3+4j
+In [1]: cplx = 3+4j
 
-In []: abs(cplx)
-Out[]: 5.0
+In [2]: abs(cplx)
+Out[2]: 5.0
 
-In []: cplx.imag
-Out[]: 4.0
+In [3]: cplx.imag
+Out[3]: 4.0
 
-In []: cplx.real
-Out[]: 3.0
+In [4]: cplx.real
+Out[4]: 3.0
   \end{lstlisting}
 \end{frame}
 
 \subsection{Boolean}
-\begin{frame}{Boolean}
-  \begin{itemize}
-    \item \kwrd{True}
-    \item \kwrd{False}
-    \item \kwrd{not}
-    \item \kwrd{and}
-    \item \kwrd{or}
-  \end{itemize}
+\begin{frame}[fragile]
+  \frametitle{Boolean}
+  \begin{lstlisting}
+In [1]: t = True
+
+In [2]: f = not t
+Out[2]: False
+
+In [3]: f or t
+Out[3]: True
+
+In [4]: f and t
+Out[4]: False
+  \end{lstlisting}
 \end{frame}
 
 \subsection{Strings}
+
 \begin{frame}[fragile]
-  \frametitle{String methods}
+  \frametitle{Strings}
 Strings were introduced previously, let us now look at them in a little more detail.
   \begin{lstlisting}
-In []: a = 'hello world'
+In [1]: w = "hello"
+
+In [2]: print w[0] + w[2] + w[-1]
+Out[2]: hlo
+
+In [3]: len(w) # guess what
+Out[3]: 5
+  \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+  \frametitle{Strings \ldots}
+  \begin{lstlisting}
+In [1]: w[0] = 'H' # Can't do that!
+--------------------------------------------
+TypeError  Traceback (most recent call last)
 
-In []: a.startswith('hell')
-Out[]: True
+/<ipython console> in <module>()
 
-In []: a.endswith('ld')
-Out[]: True
+TypeError: 'str' object does not
+         support item assignment
+  \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+  \frametitle{String methods}
+  \begin{lstlisting}
+In [1]: a = 'Hello World'
+In [2]: a.startswith('Hell')
+Out[2]: True
+
+In [3]: a.endswith('ld')
+Out[3]: True
+
+In [4]: a.upper()
+Out[4]: 'HELLO WORLD'
+
+In [5]: a.lower()
+Out[5]: 'hello world'
   \end{lstlisting}
 \end{frame}
 
 \begin{frame}[fragile]
 \frametitle{Still with strings}
-We saw split() previously. join() is the opposite of split()
+  \begin{itemize}
+    \item We saw split() yesterday
+    \item join() is the opposite of split()
+  \end{itemize}
   \begin{lstlisting}
-In []: ''.join(['a', 'b', 'c'])
-Out[]: 'abc'
+In [1]: ''.join(['a', 'b', 'c'])
+Out[1]: 'abc'
   \end{lstlisting}
-  \begin{block}{Note:}
-Strings are immutable.\\ That is string variables cannot be changed.
-  \end{block}
 \end{frame}
 
 \begin{frame}[fragile]
 \frametitle{String formatting}
   \begin{lstlisting}
-In []: x, y = 1, 1.234
-In []: 'x is %s, y is %s' %(x, y)
-Out[]: 'x is 1, y is 1.234'
+In [1]: x, y = 1, 1.234
+
+In [2]: 'x is %s, y is %s' %(x, y)
+Out[2]: 'x is 1, y is 1.234'
   \end{lstlisting}
-  \small
-\url{docs.python.org/lib/typesseq-strings.html}\\
+\emphbar{
+\url{http://docs.python.org/library/stdtypes.html}\\
+}
 \inctime{10}
 \end{frame}
 
-\section{Relational and logical operators}
+\section{Operators}
+\begin{frame}[fragile]
+  \frametitle{Arithematic operators}
+  \begin{lstlisting}
+In [1]: 1786 % 12
+Out[1]: 10
+
+In [2]: 3124 * 126789
+Out[2]: 396088836
+
+In [3]: a = 3124 * 126789
+
+In [4]: big = 1234567891234567890 ** 3
+
+In [5]: verybig = big * big * big * big
+  \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+  \frametitle{Arithematic operators \ldots}
+  \begin{lstlisting}
+In [1]: 17/2
+Out[1]: 8
+
+In [2]: 17/2.0
+Out[2]: 8.5
+
+In [3]: 17.0/2
+Out[3]: 8.5
+
+In [4]: 17.0/8.5
+Out[4]: 2.0
+  \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+  \frametitle{String operations}
+  \begin{lstlisting}
+In [1]: s = 'Hello '
+
+In [2]: p = 'World'
+
+In [3]: s + p 
+Out[3]: 'Hello World'
+
+In [4]: s * 12 
+Out[4]: 'Hello Hello Hello Hello ...'
+  \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+  \frametitle{String operations \ldots}
+  \begin{lstlisting}
+In [1]: s * s
+--------------------------------------------
+TypeError  Traceback (most recent call last)
+
+/<ipython console> in <module>()
+
+TypeError: can't multiply sequence by
+                non-int of type 'str'
+  \end{lstlisting}
+\end{frame}
+
 \begin{frame}[fragile]
   \frametitle{Relational and logical operators}
   \begin{lstlisting}
-In []: pos, zer, neg = 1, 0, -1
-In []: pos == neg
-Out[]: False
+In [1]: pos, zer, neg = 1, 0, -1
+In [2]: pos == neg
+Out[2]: False
 
-In []: pos >= neg
-Out[]: True
+In [3]: pos >= neg
+Out[3]: True
 
-In []: neg < zer < pos
-Out[]: True
+In [4]: neg < zer < pos
+Out[4]: True
 
-In []: pos + neg != zer
-Out[]: False
+In [5]: pos + neg != zer
+Out[5]: False
   \end{lstlisting}
 \inctime{5}
 \end{frame}
 
-\begin{frame}
-  {A classic problem}
+\begin{frame}[fragile]
+  \frametitle{Built-ins}
+  \begin{lstlisting}
+In [1]: int(17/2.0)
+Out[1]: 8
+
+In [2]: float(17/2)  # Recall
+Out[2]: 8.0
+
+In [3]: str(17/2.0)
+Out[3]: '8.5'
+
+In [4]: round( 7.5 )
+Out[4]: 8.0
+  \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+  \frametitle{Odds and ends}
+  \begin{itemize}
+    \item Case sensitive
+    \item Dynamically typed $\Rightarrow$ need not specify a type
+      \begin{lstlisting}
+In [1]: a = 1
+In [2]: a = 1.1
+In [3]: a = "Now I am a string!"
+      \end{lstlisting}
+    \item Comments:
+      \begin{lstlisting}
+In [4]: a = 1  # In-line comments
+In [5]: # Comment in a line to itself.
+In [6]: a = "# This is not a comment!"
+      \end{lstlisting}
+  \end{itemize}
+  \inctime{15}
+\end{frame}
+
+\begin{frame}[fragile] \frametitle{A question of good style}
+  \begin{lstlisting}
+    amount = 12.68
+    denom = 0.05
+    nCoins = round(amount/denom)
+    rAmount = nCoins * denom
+  \end{lstlisting}
+  \pause
+  \begin{block}{Style Rule \#1}
+    Naming is 80\% of programming
+  \end{block}
+\end{frame}
+
+\section{Simple IO}
+\begin{frame}{Simple IO}
   \begin{block}
-    {Interchange values}
-    How to interchange values of two variables? 
+    {Console Input}
+    \texttt{raw\_input()} waits for user input.\\Prompt string is optional.\\
+    All keystrokes are Strings!\\\texttt{int()} converts string to int.
   \end{block}
-  \pause
-  \begin{block}{Note:}
-    This Python idiom works for all types of variables.\\
-They need not be of the same type!
+  \begin{block}
+    {Console output}
+    \texttt{print} is straight forward. Note the distinction between \texttt{print x} and \texttt{print x,}
   \end{block}
-  \inctime{10}
 \end{frame}
 
 \section{Control flow}
@@ -279,21 +432,9 @@ else:
 \end{lstlisting}
 \end{frame}
 
-\begin{frame}{Simple IO}
-  \begin{block}
-    {Console Input}
-    \texttt{raw\_input()} waits for user input.\\Prompt string is optional.\\
-    All keystrokes are Strings!\\\texttt{int()} converts string to int.
-  \end{block}
-  \begin{block}
-    {Console output}
-    \texttt{print} is straight forward. Note the distinction between \texttt{print x} and \texttt{print x,}
-  \end{block}
-\end{frame}
-
 \subsection{Basic Looping}
 \begin{frame}[fragile]
-  \frametitle{\kwrd{while}}
+  \frametitle{\typ{while}}
 Example: Fibonacci series
   \begin{lstlisting}
 # the sum of two elements
@@ -307,7 +448,7 @@ while b < 10:
 \end{frame}
 
 \begin{frame}[fragile]
-\frametitle{\kwrd{range()}}
+\frametitle{\typ{range()}}
 \kwrd{range([start,] stop[, step])}\\
 \begin{itemize}
   \item \alert {range() returns a list of integers}
@@ -316,7 +457,7 @@ while b < 10:
 \end{frame}
 
 \begin{frame}[fragile]
-  \frametitle{\kwrd{for}}
+  \frametitle{\typ{for} \ldots \typ{range()}}
 Example: print squares of first \typ{n} numbers
   \begin{lstlisting}
 In []: for i in range(5):
@@ -332,85 +473,44 @@ In []: for i in range(5):
 \inctime{15}
 \end{frame}
 
-\section{Lists}
-\begin{frame}[fragile]
-\frametitle{More List methods}
-\begin{lstlisting}
-In []: lst = [1,2,3,4,5,6,7,8]
-In []: lst.reverse()
-In []: lst
-Out[]: [8, 7, 6, 5, 4, 3, 2, 1]
-
-In []: lst.extend([0, -1, -2])
-In []: lst
-Out[]: [8, 7, 6, 5, 4, 3, 2, 1, 0, -1]
-
-In []: lst.remove(0)
-In []: lst
-Out[]: [8, 7, 6, 5, 4, 3, 2, 1, -1]
-\end{lstlisting}
-\end{frame}
-
-\begin{frame}[fragile]
-\frametitle{List containership}
-\begin{lstlisting}
-In []: a = 8
-
-In []: a in lst
-Out[]: True
-
-In []: b = 10
-In []: b in lst
-Out[]: False
-
-In []: b not in lst
-Out[]: True
-\end{lstlisting}
-\inctime{10}
+\subsection{Exercises}
+\begin{frame}
+  \frametitle{Problem set 1}
+  \begin{itemize}
+    \item All the problems can be\\
+      solved using \kwrd{if} and \kwrd{while} 
+  \end{itemize}
 \end{frame}
 
-\section{Tuples}
-\begin{frame}[fragile]
-\frametitle{Tuples: Immutable lists}
-\begin{lstlisting}
-In []: tup = (1,2,3,4,5,6,7,8)
-In []: tup[0]+tup[3]+tup[-1]
-Out[]: 13
-\end{lstlisting}
-\begin{block}{Note:}
-\begin{itemize}
-\item Tuples are immutable - cannot be changed
-\item Multiple return values in a function are actually tuples
-\item Tuples are working behind the scenes in exchanging values - Tuple Unpacking
-\end{itemize}
-\end{block}
-\inctime{5}
+\begin{frame}{Problem 1.1}
+  Write a program that displays all three digit numbers that are equal to the sum of the cubes of their digits. That is, print numbers $abc$ that have the property $abc = a^3 + b^3 + c^3$\\
+\vspace*{0.2in}
+\emphbar{These are called $Armstrong$ numbers.}
 \end{frame}
+  
+\begin{frame}{Problem 1.2 - Collatz sequence}
+\begin{enumerate}
+  \item Start with an arbitrary (positive) integer. 
+  \item If the number is even, divide by 2; if the number is odd, multiply by 3 and add 1.
+  \item Repeat the procedure with the new number.
+  \item It appears that for all starting values there is a cycle of 4, 2, 1 at which the procedure loops.
+\end{enumerate}
+    Write a program that accepts the starting value and prints out the Collatz sequence.
 
-\section{Dictionaries}
-\begin{frame}[fragile]
-\frametitle{Dictionaries}
-  \alert {lists and tuples: integer indexes :: dictionaries: string indexes}
-\begin{lstlisting}
-In []: player = {'Mat': 134,'Inn': 233, 
-           'Runs': 10823, 'Avg': 52.53}
-
-In []: player['Avg']
-Out[]: 52.530000000000001
-In []: player.keys()
-Out[]: ['Runs', 'Inn', 'Avg', 'Mat']
-In []: player.values()
-Out[]: [10823, 233, 
-       52.530000000000001, 134]
-\end{lstlisting}
 \end{frame}
 
-\begin{frame}{Dictionaries}
-\begin{itemize}
-\item Duplicate keys are not allowed!
-\item Dictionaries are iterable through keys.
-\end{itemize}
-\inctime{5}
+\begin{frame}[fragile]{Problem 1.4}
+  Write a program that prints the following pyramid on the screen. 
+  \begin{lstlisting}
+1
+2  2
+3  3  3
+4  4  4  4
+  \end{lstlisting}
+The number of lines must be obtained from the user as input.\\
+\pause
+\emphbar{When can your code fail?}
+\only<2->{\inctime{20}}
 \end{frame}
 
 \end{document}
diff --git a/day2/3Dplotting.tex b/day2/session3.tex
index 16c0bd2..f623b32 100644
--- a/day2/3Dplotting.tex
+++ b/day2/session3.tex
@@ -97,7 +97,7 @@
 % Title page
 \title[]{3D data Visualization}
 
-\author[FOSSEE Team] {FOSSEE}
+\author[FOSSEE] {FOSSEE}
 
 \institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay}
 \date[] {1, November 2009\\Day 2, Session 3}
@@ -157,22 +157,22 @@
 \end{frame}
 
 
-\begin{frame}
-    \frametitle{Is this new?}    
-    \begin{center}
-    We have moved from:
-    \end{center}
-    \begin{columns}
-    \column{}
-    \hspace*{-1in}    
-    \includegraphics[width=1.75in,height=1.75in, interpolate=true]{data/3832}      
-    \column{}\hspace*{-0.25in}
-    To
-    \column{}
-    \hspace*{-1in}
-    \includegraphics[width=1.75in, height=1.75in, interpolate=true]{data/torus}  
-    \end{columns}
-\end{frame}
+%% \begin{frame}
+%%     \frametitle{Is this new?}    
+%%     \begin{center}
+%%     We have moved from:
+%%     \end{center}
+%%     \begin{columns}
+%%     \column{}
+%%     \hspace*{-1in}    
+%%     \includegraphics[width=1.75in,height=1.75in, interpolate=true]{data/3832}      
+%%     \column{}\hspace*{-0.25in}
+%%     To
+%%     \column{}
+%%     \hspace*{-1in}
+%%     \includegraphics[width=1.75in, height=1.75in, interpolate=true]{data/torus}  
+%%     \end{columns}
+%% \end{frame}
 
 \begin{frame}
     \frametitle{3D visualization}
@@ -238,7 +238,7 @@
     \frametitle{Using mlab}
 
     \begin{lstlisting}
->>> from enthought.mayavi import mlab
+In []:from enthought.mayavi import mlab
     \end{lstlisting}
 
     \vspace*{0.5in}
@@ -248,9 +248,9 @@
     \vspace*{0.25in}
 
     \begin{lstlisting}
->>> mlab.test_<TAB>
->>> mlab.test_contour3d()
->>> mlab.test_contour3d??
+In []: mlab.test_<TAB>
+In []: mlab.test_contour3d()
+In []: mlab.test_contour3d??
     \end{lstlisting}
 \end{frame}
 
@@ -270,72 +270,31 @@
 \end{frame}
 
 \begin{frame}[fragile]
-    \frametitle{plotting 3-D Surface: $x^2+y^2-z^2=1$}
-    \begin{lstlisting}
-u,v = mgrid[-2:2:100j, -pi:pi:100j]
-x=sqrt(u*u+1)*cos(v)
-y=sqrt(u*u+1)*sin(v)
-z=u
-mlab.mesh(x,y,z)
-    \end{lstlisting}
-\begin{figure}
-\includegraphics[width=1in, height=1in, interpolate=true]{data/hyperboloid}
-\end{figure}
-\end{frame}
-
-\begin{frame}[fragile]
-    \frametitle{mgrid}    
-    \begin{itemize}
-      \item Creates a multidimensional ``meshgrid''
-      
-      \item In this particular case, creates 2 2D arrays: u,v.
-    \end{itemize}      
-    \begin{lstlisting}
-In []: mgrid[0:3,0:3]
-Out[]: 
-array([[[0, 0, 0],
-        [1, 1, 1],
-        [2, 2, 2]],
-
-       [[0, 1, 2],
-        [0, 1, 2],
-        [0, 1, 2]]])
-    \end{lstlisting}    
-\end{frame}
-
-\begin{frame}[fragile]
-    \frametitle{mesh}
-      \begin{itemize}
-        \item Plots a surface from data supplied as 2D arrays.
-      \end{itemize}      
-\end{frame}
-
-\begin{frame}[fragile]
     \frametitle{\mlab\ plotting functions}
     \begin{columns}
         \column{0.25\textwidth}
-        \myemph{Points in 3D space}
+        \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)
+In []: from numpy import *
+In []: t = linspace(0, 2*pi, 50)
+In []: u = cos(t) * pi
+in []: x, y, z = sin(u), cos(u), sin(t)
     \end{lstlisting}
-    \emphbar{\PythonCode{>>> mlab.points3d(x, y, z)}}
+    \emphbar{\PythonCode{In []: mlab.points3d(x, y, z)}}
 \end{frame}
 
 \begin{frame}
   \begin{columns}
         \column{0.25\textwidth}
-        \myemph{Connected points in 3D space}
+        \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)}}
+  \emphbar{\PythonCode{In []: mlab.plot3d(x, y, z, t)}}
 
     Plots lines between the points
     
@@ -349,11 +308,11 @@ array([[[0, 0, 0],
         \pgfimage[width=2in]{MEDIA/m2/mlab/surf_ex}
     \end{columns}            
     \begin{lstlisting}
->>> x, y = mgrid[-3:3:100j,-3:3:100j]
->>> z = sin(x*x + y*y)
+In []: x, y = mgrid[-3:3:100j,-3:3:100j]
+In []: z = sin(x*x + y*y)
     \end{lstlisting}
 
-    \emphbar{\PythonCode{>>> mlab.surf(x, y, z)}}
+    \emphbar{\PythonCode{In []: mlab.surf(x, y, z)}}
 
     \alert{Assumes the points are rectilinear}
 
@@ -363,18 +322,18 @@ array([[[0, 0, 0],
     \myemph{\Large 2D data: \texttt{mlab.mesh}}
     \vspace*{0.25in}
 
-    \emphbar{\PythonCode{>>> mlab.mesh(x, y, z)}}
+    \emphbar{\PythonCode{In []: mlab.mesh(x, y, z)}}
 
     \alert{Points needn't be regular}
 
     \vspace*{0.25in}
 \begin{lstlisting}
->>> phi, theta = numpy.mgrid[0:pi:20j, 
+In []: 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, 
+In []: x = sin(phi)*cos(theta)
+In []: y = sin(phi)*sin(theta)
+In []: z = cos(phi)
+In []: mlab.mesh(x, y, z, 
 ...           representation=
 ...           'wireframe')
 \end{lstlisting}
@@ -390,10 +349,10 @@ array([[[0, 0, 0],
         \pgfimage[width=1.5in]{MEDIA/m2/mlab/contour3d}\\        
     \end{columns}
 \begin{lstlisting}
->>> x, y, z = ogrid[-5:5:64j, 
+In []: x, y, z = ogrid[-5:5:64j, 
 ...                -5:5:64j, 
 ...                -5:5:64j]
->>> mlab.contour3d(x*x*0.5 + y*y + 
+In []: mlab.contour3d(x*x*0.5 + y*y + 
                    z*z*2)
 \end{lstlisting}
 \end{frame}
@@ -406,7 +365,7 @@ array([[[0, 0, 0],
     \pgfimage[width=2in]{MEDIA/m2/mlab/quiver3d_ex}\\
     
 \begin{lstlisting}
->>> mlab.test_quiver3d()
+In []: mlab.test_quiver3d()
 \end{lstlisting}
 
 \emphbar{\PythonCode{obj = mlab.quiver3d(x, y, z, u, v, w)}}
@@ -552,6 +511,15 @@ mlab.show()
 
   \end{lstlisting}
 \end{frame}
-  
+
+\begin{frame}
+  \frametitle{We have covered:}
+  \begin{itemize}
+  \item Need of visualization.
+  \item Using mlab to create 3 D plots.
+  \item Mayavi Toolkit.
+  \end{itemize}
+\end{frame}
+
 \end{document}
 
diff --git a/day2/session4.tex b/day2/session4.tex
new file mode 100644
index 0000000..d7aae3f
--- /dev/null
+++ b/day2/session4.tex
@@ -0,0 +1,386 @@
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+% 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[]{Debugging and \\Test Driven Approach}
+
+\author[FOSSEE] {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{Debugging}
+\subsection{Errors and Exceptions}
+\begin{frame}[fragile]
+ \frametitle{Errors}
+ \begin{lstlisting}
+>>> while True print 'Hello world'
+ \end{lstlisting}
+\pause
+  \begin{lstlisting}
+  File "<stdin>", line 1, in ?
+    while True print 'Hello world'
+                   ^
+SyntaxError: invalid syntax
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Exceptions}
+ \begin{lstlisting}
+>>> print spam
+\end{lstlisting}
+\pause
+\begin{lstlisting}
+Traceback (most recent call last):
+  File "<stdin>", line 1, in <module>
+NameError: name 'spam' is not defined
+\end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]
+ \frametitle{Exceptions}
+ \begin{lstlisting}
+>>> 1 / 0
+\end{lstlisting}
+\pause
+\begin{lstlisting}
+Traceback (most recent call last):
+  File "<stdin>", line 1, in <module>
+ZeroDivisionError: integer division 
+or modulo by zero
+\end{lstlisting}
+\end{frame}
+
+\subsection{Strategy}
+\begin{frame}[fragile]
+    \frametitle{Debugging effectively}
+    \begin{itemize}
+        \item \kwrd{print} based strategy
+        \item Process:
+    \end{itemize}
+\begin{center}
+\pgfimage[interpolate=true,width=5cm,height=5cm]{DebugginDiagram.png}
+\end{center}
+\end{frame}
+
+\begin{frame}[fragile]
+    \frametitle{Debugging effectively}
+    \begin{itemize}
+      \item Using \typ{\%debug} in IPython
+    \end{itemize}
+\end{frame}
+
+\begin{frame}[fragile]
+\frametitle{Debugging in IPython}
+\small
+\begin{lstlisting}
+In [1]: import mymodule
+In [2]: mymodule.test()
+---------------------------------------------
+NameError   Traceback (most recent call last)
+<ipython console> in <module>()
+mymodule.py in test()
+      1 def test():
+----> 2     print spam
+NameError: global name 'spam' is not defined
+
+In [3]: %debug
+> mymodule.py(2)test()
+      0     print spam
+ipdb> 
+\end{lstlisting}
+\inctime{15} 
+\end{frame}
+
+\subsection{Exercise}
+\begin{frame}[fragile]
+\frametitle{Debugging: Exercise}
+\small
+\begin{lstlisting}
+import keyword
+f = open('/path/to/file')
+
+freq = {}
+for line in f:
+    words = line.split()
+    for word in words:
+        key = word.strip(',.!;?()[]: ')
+        if keyword.iskeyword(key):
+            value = freq[key]
+            freq[key] = value + 1
+
+print freq
+\end{lstlisting}
+\inctime{10}
+\end{frame}
+
+%% \begin{frame}
+%%     \frametitle{Testing}
+   
+%%     \begin{itemize}
+%%         \item Writing tests is really simple!
+
+%%         \item Using nose.
+
+%%         \item Example!
+%%     \end{itemize}
+%% \end{frame}
+
+\section{Test Driven Approach}
+\begin{frame}
+    \frametitle{Need of Testing!}
+   
+    \begin{itemize}
+        \item Quality
+        \item Regression
+        \item Documentation
+    \end{itemize}
+    %% \vspace*{0.25in}
+    %% \emphbar{It is to assure that section of code is working as it is supposed to work}
+\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:
+    \begin{center}
+    $gcd(a,b)=gcd(b,b\%a)$
+    \end{center}
+    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}
+  \frametitle{We have learned}
+  \begin{itemize}
+  \item Following and Resolving Error Messages.
+  \item Exceptions.
+  \item Approach for Debugging.
+  \item Writting and running tests.
+  \end{itemize}
+\end{frame}
+
+\end{document}
diff --git a/day2/session5.tex b/day2/session5.tex
index f3b517e..5a5949d 100644
--- a/day2/session5.tex
+++ b/day2/session5.tex
@@ -147,14 +147,14 @@
 
 \begin{frame}[fragile]
   \frametitle{Problem set 4}
-  Finite difference
+  Central difference
   \begin{equation*}
-  \frac{sin(x+h)-sin(x)}{h}
+  \frac{sin(x+h)-sin(x-h)}{2h}
   \end{equation*}
   \begin{lstlisting}
-  >>> x = linspace(0,2*pi,100)
-  >>> y = sin(x)
-  >>> deltax = x[1] - x[0]
+  In []: x = linspace(0, 2*pi, 100)
+  In []: y = sin(x)
+  In []: deltax = x[1] - x[0]
   \end{lstlisting}
   \pause
     \begin{enumerate}