--- a/day1/session4.tex	Thu Jan 21 17:16:33 2010 +0530
+++ b/day1/session4.tex	Thu Jan 21 17:49:05 2010 +0530
@@ -134,15 +134,15 @@
 \begin{frame}[fragile]
 \frametitle{Matrices: Initializing}
 \begin{lstlisting}
-In []: c = array([[1,1,2],
-                  [2,4,1],
-                  [-1,3,7]])
+In [23]: c = array([[11,12,13],
+                  [21,22,23],
+                  [31,32,33]])
 
 In []: c
 Out[]: 
-array([[1,1,2],
-       [2,4,1],
-       [-1,3,7]])
+array([[11, 12, 13],
+       [21, 22, 23],
+       [31, 32, 33]])
 \end{lstlisting}
 \end{frame}
 
@@ -174,16 +174,16 @@
   \begin{lstlisting}
 In []: c
 Out[]: 
-array([[1,1,2],
-       [2,4,1],
-       [-1,3,7]])
+array([[11, 12, 13],
+       [21, 22, 23],
+       [31, 32, 33]])
 
 In []: c[1][2]
-Out[]: 1
+Out[]: 23
 In []: c[1,2]
-Out[]: 1
+Out[]: 23
 In []: c[1]
-Out[]: array([2, 4, 1])
+Out[]: array([21, 22, 23])
   \end{lstlisting}
 \end{frame}
 
@@ -191,19 +191,19 @@
   \frametitle{Changing elements}
   \begin{small}
   \begin{lstlisting}
-In []: c[1,1] = -2
+In []: c[1,1] = -22
 In []: c
 Out[]: 
-array([[ 1,  1,  2],
-       [ 2, -2,  1],
-       [-1,  3,  7]])
+array([[ 11,  12,  13],
+       [ 21, -22,  23],
+       [ 31,  32,  33]])
 
-In []: c[1] = [0,0,0]
+In []: c[1] = 0
 In []: c
 Out[]: 
-array([[ 1,  1,  2],
+array([[11, 12, 13],
        [ 0,  0,  0],
-       [-1,  3,  7]])
+       [31, 32, 33]])
   \end{lstlisting}
   \end{small}
 How to change one \alert{column}?
@@ -214,20 +214,20 @@
 \begin{small}
   \begin{lstlisting}
 In []: c[:,1]
-Out[]: array([1, 0, 3])
+Out[]: array([12,  0, 32])
 
 In []: c[1,:]
 Out[]: array([0, 0, 0])
 
 In []: c[0:2,:]
 Out[]: 
-array([[1, 1, 2],
-       [0, 0, 0]])
+array([[11, 12, 13],
+       [ 0,  0,  0]])
 
 In []: c[1:3,:]
 Out[]: 
 array([[ 0,  0,  0],
-       [-1,  3,  7]])
+       [31, 32, 33]])
   \end{lstlisting}
 \end{small}
 \end{frame}
@@ -238,18 +238,18 @@
   \begin{lstlisting}
 In []: c[:2,:]
 Out[]: 
-array([[1, 1, 2],
-       [0, 0, 0]])
+array([[11, 12, 13],
+       [ 0,  0,  0]])
 
 In []: c[1:,:]
 Out[]: 
 array([[ 0,  0,  0],
-       [-1,  3,  7]])
+       [31, 32, 33]])
 
 In []: c[1:,:2]
 Out[]: 
 array([[ 0,  0],
-       [-1,  3]])
+       [31, 32]])
   \end{lstlisting}
 
 \end{small}
@@ -261,19 +261,19 @@
   \begin{lstlisting}
 In []: c[::2,:]
 Out[]: 
-array([[ 1,  1,  2],
-       [-1,  3,  7]])
+array([[11, 12, 13],
+       [31, 32, 33]])
 
 In []: c[:,::2]
 Out[]: 
-xarray([[ 1,  2],
+array([[11, 13],
        [ 0,  0],
-       [-1,  7]])
+       [31, 33]])
 
 In []: c[::2,::2]
 Out[]: 
-array([[ 1,  2],
-       [-1,  7]])
+array([[11, 13],
+       [31, 33]])
   \end{lstlisting}
   \end{small}
 \end{frame}
@@ -477,11 +477,16 @@
 
 \begin{frame}
 \frametitle{Least Square Fit Curve}
+\begin{center}
 \begin{itemize}
-\item $T^2$ and $L$ have a linear relationship
-\item Hence, Least Square Fit Curve is a line
-\item we shall use the \typ{lstsq} function
+\item $L \alpha T^2$
+\item Best Fit Curve $\rightarrow$ Linear
+  \begin{itemize}
+  \item Least Square Fit
+  \end{itemize}
+\item \typ{lstsq()} 
 \end{itemize}
+\end{center}
 \end{frame}
 
 \begin{frame}[fragile]