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diff --git a/accessing_parts_of_arrays/quickref.tex b/accessing_parts_of_arrays/quickref.tex
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+\textbf{Accessing parts of arrays}
+
+\lstinline|C[i-1, j-1]| to access element i, j in C (mxn).
+\lstinline|C[i-1]| to access i^{th} row
+\lstinline|C[:, j-1]| to access j^{th} column
+
+Assigning to accessed elements, changes them. 
+
+\lstinline|A[m:n:o]| accesses the rows from \lstinline|m|
+to \lstinline|n| (excluded) in steps of \lstinline|o|
+
+Similarly, \lstinline|C[m:n:o, p:q:r]|
diff --git a/accessing_parts_of_arrays/script.rst b/accessing_parts_of_arrays/script.rst
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+.. Objectives
+.. ----------
+   
+   .. By the end of this tutorial, you will be able to:
+   
+   ..   1. Access and change individual elements of arrays, both one
+   ..   dimensional and multi-dimensional.
+   ..   2. Access and change rows and columns of arrays. 
+   ..   3. Access and change other chunks from an array, using slicing
+   ..   and striding. 
+   ..   4. Read images into arrays and perform processing on them, using
+   ..   simple array manipulations. 
+
+.. Prerequisites
+.. -------------
+
+..   1. getting started with arrays
+
+.. #[anand: internal reviewer not mentioned]     
+.. Author              : Puneeth
+   Internal Reviewer   : 
+   External Reviewer   :
+   Language Reviewer   : Bhanukiran
+   Checklist OK?       : <06-11-2010, Anand,  OK> [2010-10-05]
+
+Script
+------
+
+{{{ Screen shows welcome slide }}}
+
+Welcome to the tutorial on accessing pieces of arrays
+
+{{{ Show the outline for this tutorial }}} 
+
+In this tutorial we shall learn to access individual elements of
+arrays, get rows and columns and other chunks of arrays using
+slicing and striding. 
+
+{{{ switch back to the terminal }}}
+
+As usual, we start IPython, using 
+::
+
+  ipython -pylab 
+
+
+{{ Show the slide with the arrays, A and C }}
+
+Let us have two arrays, A and C, as the sample arrays that we will
+use to work through this tutorial. 
+
+::
+
+  A = array([12, 23, 34, 45, 56])
+
+  C = array([[11, 12, 13, 14, 15],
+             [21, 22, 23, 24, 25],
+             [31, 32, 33, 34, 35],
+             [41, 42, 43, 44, 45],
+             [51, 52, 53, 54, 55]])
+
+Pause the video here and make sure you have the arrays A and C,
+typed in correctly.
+
+{{{ Pause the recording and type the arrays A,C }}}
+
+Let us begin with the most elementary thing, accessing individual
+elements. Also, let us first do it with the one-dimensional array
+A, and then do the same thing with the two-dimensional array. 
+
+To access, the element 34 in A, we say, 
+
+::
+
+  A[2]
+
+A of 2, note that we are using square brackets.
+
+Like lists, indexing starts from 0 in arrays, too. So, 34, the
+third element has the index 2. 
+
+Now, let us access the element 34 from C. To do this, we say
+::
+
+  C[2, 3]
+
+C of 2,3.
+
+34 is in the third row and the fourth column, and since indexing
+begins from zero, the row index is 2 and column index is 3. 
+
+Now, that we have accessed one element of the array, let us change
+it. We shall change the 34 to -34 in both A and C. To do this, we
+simply assign the new value after accessing the element. 
+::
+
+  A[2] = -34
+  C[2, 3] = -34
+
+Now that we have accessed and changed a single element, let us
+access and change more than one element at a time; first rows and
+then columns.
+
+Let us access one row of C, say the third row. We do it by saying, 
+::
+
+  C[2] 
+
+How do we access the last row of C? We could say,
+::
+
+  C[4] 
+
+for the fifth row, or as with lists, use negative indexing and say
+::
+
+  C[-1]
+
+Now, we could change the last row into all zeros, using either 
+::
+
+  C[-1] = [0, 0, 0, 0, 0]
+
+or 
+
+::
+  
+  C[-1] = 0
+
+Now, how do we access one column of C? As with accessing individual
+elements, the column is the second parameter to be specified (after
+the comma). The first parameter, is replaced with a ``:``. This
+specifies that we want all the elements of that dimension, instead of
+just one particular element. We access the third column by
+
+::
+  
+  C[:, 2]
+
+Following is an exercise that you must do. 
+
+{{ show slide containing Question 1}} 
+
+%%1%% Change the last column of C to zeroes. 
+
+Please, pause the video here. Do the exercises and then continue. 
+
+::
+  
+  C[:, -1] = 0
+
+Since A is one dimensional, rows and columns of A don't make much
+sense. It has just one row and 
+::
+
+  A[:] 
+
+gives the whole of A. 
+
+Following is an exercise that you must do. 
+
+{{ show slide containing Question 2}} 
+
+%%2%% Change ``A`` to ``[11, 12, 13, 14, 15]``. 
+
+Please, pause the video here. Do the exercises and then continue. 
+
+To change A, we say
+::
+
+  A[:] = [11, 12, 13, 14, 15]
+
+Now, that we know how to access, rows and columns of an array, we
+shall learn how to access other pieces of an array. For this
+purpose, we will be using image arrays. 
+
+To read an image into an array, we use the ``imread`` command. We
+shall use the image ``squares.png`` present in ``/home/fossee``. We
+shall first navigate to that path in the OS and see what the image
+contains. 
+
+{{{ switch to the browser and show the image }}}
+
+{{{ switch back to the ipython terminal }}}
+
+Let us now read the data in ``squares.png`` into the array ``I``. 
+::
+
+  I = imread('/home/fossee/squares.png')
+
+We can see the contents of the image, using the command
+``imshow``. We say, 
+::
+
+  imshow(I) 
+
+to see what has been read into ``I``. We do not see white and black
+because, ``pylab`` has mapped white and black to different
+colors. This can be changed by using a different colormap. 
+
+To see that ``I`` is really, just an array, we say, 
+::
+
+  I 
+
+at the prompt, and see that an array is displayed. 
+
+To check the dimensions of any array, we can use ``.shape``. We say
+
+::
+
+  I.shape 
+
+to get the dimensions of the image. As we can see, ``squares.png``
+has the dimensions of 300x300. 
+
+Our goal for this part of the tutorial would be to get the
+top-left quadrant of the image. To do this, we need to access, a
+few of the rows and a few of the columns of the array. 
+
+To access, the third column of C, we said, ``C[:, 2]``. Essentially,
+we are accessing all the rows in column three of C. Now, let us
+modify this to access only the first three rows, of column three
+of C. 
+
+We say, 
+::
+
+  C[0:3, 2]
+
+to get the elements of rows indexed from 0 to 3, 3 not included
+and column indexed 2. Note that, the index before the colon is
+included and the index after it is not included in the slice that
+we have obtained. This is very similar to the ``range`` function,
+where ``range`` returns a list, in which the upper limit or stop
+value is not included.
+
+Now, if we wish to access the elements of row with index 2, and in
+columns indexed 0 to 2 (included), we say, 
+::
+
+  C[2, 0:3]
+
+Following is an exercise that you must do. 
+
+{{ show slide containing Question 3 }} 
+
+%%3%% First, obtain the elements [22, 23] from C. Then, obtain the
+elements [11, 21, 31, 41] from C. Finally, obtain the elements [21,
+31, 41, 0]. 
+
+Please, pause the video here. Do the exercises and then continue. 
+
+{{ show slide containing Solution 3 }}
+
+::
+
+  C[1, 1:3] 
+
+gives the elements [22, 23]
+::
+
+  C[0:4, 0]
+
+gives the elements [11, 21, 31, 41]
+::
+
+  C[1:5, 0]
+
+gives the elements [21, 31, 41, 0]
+
+Note that when specifying ranges, if you are starting from the
+beginning or going up-to the end, the corresponding element may be
+dropped. So, in the previous example to obtain [11, 21, 31, 41], we
+could have simply said, ::
+
+  C[:4, 0]
+
+and 
+::
+
+  C[1:, 0]
+
+gives the elements [21, 31, 41, 0]. If we skip both the indexes,
+we get the slice from end to end, as we already know. 
+
+Following is an exercise that you must do. 
+
+{{ show slide containing Question 4 }} 
+
+%%4%% Obtain the elements [[23, 24], [33, -34]] from C. 
+
+Please, pause the video here. Do the exercises and then continue. 
+
+{{ show slide containing Solution 4 }} 
+
+::
+
+  C[1:3, 2:4] 
+
+gives us the elements, [[23, 24], [33, -34]]. 
+
+Now, we wish to obtain the top left quarter of the image. How do
+we go about doing it? Since, we know the shape of the image to be
+300, we know that we need to get the first 150 rows and first 150
+columns. 
+::
+
+  I[:150, :150]
+
+gives us the top-left corner of the image. 
+
+We use the ``imshow`` command to see the slice we obtained in the
+form of an image and confirm. 
+::
+
+  imshow(I[:150, :150])
+
+Following is an exercise that you must do. 
+
+{{ show slide containing Question 5 }} 
+
+%%5%% Obtain the square in the center of the image.
+
+Please, pause the video here. Do the exercises and then continue. 
+
+{{ show slide containing Solution 5 }} 
+
+::
+
+  imshow(I[75:225, 75:225])
+
+Our next goal is to compress the image, using a very simple
+technique to reduce the space that the image takes on disk while
+not compromising too heavily on the image quality. The idea is to
+drop alternate rows and columns of the image and save it. This way
+we will be reducing the data to a fourth of the original data but
+losing only so much of visual information. 
+
+We shall first learn the idea of striding using the smaller array
+C. Suppose we wish to access only the odd rows and columns (first,
+third, fifth). We do this by, 
+::
+
+  C[0:5:2, 0:5:2]
+
+if we wish to be explicit, or simply, 
+::
+
+  C[::2, ::2]
+
+This is very similar to the step specified to the ``range``
+function. It specifies, the jump or step in which to move, while
+accessing the elements. If no step is specified, a default value
+of 1 is assumed. 
+::
+
+  C[1::2, ::2] 
+
+gives the elements, [[21, 23, 0], [41, 43, 0]]
+
+{{ show slide containing Question 6 }} 
+
+Following is an exercise that you must do. 
+
+%%6%% Obtain the following. 
+[[12, 0], [42, 0]]
+[[12, 13, 14], [0, 0, 0]]
+
+Please, pause the video here. Do the exercises and then continue. 
+
+{{ show slide containing Solution 6 }} 
+
+::
+
+  C[::3, 1::3]
+
+gives the elements [[12, 0], [42, 0]]
+::
+
+  C[::4, 1:4]
+
+gives the elements [[12, 13, 14], [0, 0, 0]]
+
+Now, that we know how to stride over an array, we can drop
+alternate rows and columns out of the image in I. 
+::
+
+  I[::2, ::2]
+
+To see this image, we say, 
+::
+
+  imshow(I[::2, ::2])
+
+This does not have much data to notice any real difference, but
+notice that the scale has reduced to show that we have dropped
+alternate rows and columns. If you notice carefully, you will be
+able to observe some blurring near the edges. To notice this
+effect more clearly, increase the step to 4. 
+::
+
+  imshow(I[::4, ::4])
+
+{{{ show summary slide }}}
+
+That brings us to the end of this tutorial. In this tutorial, we
+have learnt to access parts of arrays, specifically individual
+elements, rows and columns and larger pieces of arrays. We have
+also learnt how to modify arrays, element wise or in larger
+pieces.
+
+{{{ Show the "sponsored by FOSSEE" slide }}}
+
+This tutorial was created as a part of FOSSEE project, NME ICT, MHRD India
+
+Hope you have enjoyed and found it useful.
+Thank you!
+
+.. 
+   Local Variables:
+   mode: rst
+   indent-tabs-mode: nil
+   sentence-end-double-space: nil
+   fill-column: 70
+   End:
diff --git a/accessing_parts_of_arrays/slides.org b/accessing_parts_of_arrays/slides.org
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--- /dev/null
+++ b/accessing_parts_of_arrays/slides.org
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+#+LaTeX_CLASS: beamer
+#+LaTeX_CLASS_OPTIONS: [presentation]
+#+BEAMER_FRAME_LEVEL: 1
+
+#+BEAMER_HEADER_EXTRA: \usetheme{Antibes}\usecolortheme{lily}\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:    Accessing parts of arrays
+#+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
+
+* Outline
+  - Manipulating one and multi dimensional arrays
+  - Access and change individual elements 
+  - Access and change rows and columns 
+  - Slicing and striding on arrays to access chunks 
+  - Read images into arrays and manipulations
+* Sample Arrays
+  #+begin_src python
+    In []: A = array([12, 23, 34, 45, 56])
+    
+    In []: C = array([[11, 12, 13, 14, 15],
+                      [21, 22, 23, 24, 25],
+                      [31, 32, 33, 34, 35],
+                      [41, 42, 43, 44, 45],
+                      [51, 52, 53, 54, 55]])
+    
+  #+end_src
+* Question 1
+  Change the last column of ~C~ to zeroes. 
+* Solution 1
+  #+begin_src python
+    In []:  C[:, -1] = 0
+  #+end_src
+* Question 2
+  Change ~A~ to ~[11, 12, 13, 14, 15]~. 
+* Solution 2
+  #+begin_src python
+    In []:  A[:] = [11, 12, 13, 14, 15]
+  #+end_src
+* squares.png
+  #+begin_latex
+    \begin{center}
+      \includegraphics[scale=0.6]{squares}    
+    \end{center}
+  #+end_latex
+* Question 3
+  - obtain ~[22, 23]~ from ~C~. 
+  - obtain ~[11, 21, 31, 41]~ from ~C~. 
+  - obtain ~[21, 31, 41, 0]~.   
+* Solution 3
+  #+begin_src python
+    In []:  C[1, 1:3]
+    In []:  C[0:4, 0]
+    In []:  C[1:5, 0]
+  #+end_src
+* Question 4
+  Obtain ~[[23, 24], [33, -34]]~ from ~C~
+* Solution 4
+  #+begin_src python
+    In []:  C[1:3, 2:4]
+  #+end_src
+* Question 5
+  Obtain the square in the center of the image
+* Solution 5
+  #+begin_src python
+    In []: imshow(I[75:225, 75:225])
+  #+end_src
+* Question 6
+  Obtain the following
+  #+begin_src python
+    [[12, 0], [42, 0]]
+    [[12, 13, 14], [0, 0, 0]]
+  #+end_src
+
+* Solution 6
+  #+begin_src python
+    In []: C[::3, 1::3]
+    In []: C[::4, 1:4]
+  #+end_src
+* Summary
+  You should now be able to --
+  - Manipulate single \& multi dimensional arrays
+      - Access and change individual elements 
+      - Access and change rows and columns 
+      - Slice and stride on arrays
+  - Read images into arrays and manipulate them.
+* Thank you!
+#+begin_latex
+  \begin{block}{}
+  \begin{center}
+  This spoken tutorial has been produced by the
+  \textcolor{blue}{FOSSEE} team, which is funded by the 
+  \end{center}
+  \begin{center}
+    \textcolor{blue}{National Mission on Education through \\
+      Information \& Communication Technology \\ 
+      MHRD, Govt. of India}.
+  \end{center}  
+  \end{block}
+#+end_latex
+
+
diff --git a/accessing_parts_of_arrays/slides.org.orig b/accessing_parts_of_arrays/slides.org.orig
new file mode 100644
index 0000000..82801ca
--- /dev/null
+++ b/accessing_parts_of_arrays/slides.org.orig
@@ -0,0 +1,123 @@
+#+LaTeX_CLASS: beamer
+#+LaTeX_CLASS_OPTIONS: [presentation]
+#+BEAMER_FRAME_LEVEL: 1
+
+#+BEAMER_HEADER_EXTRA: \usetheme{Antibes}\usecolortheme{lily}\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:    Accessing parts of arrays
+#+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
+
+* Outline
+  - Manipulating one and multi dimensional arrays
+  - Access and change individual elements 
+  - Access and change rows and columns 
+  - Slicing and striding on arrays to access chunks 
+  - Read images into arrays and manipulations
+* Sample Arrays
+  #+begin_src python
+    In []: A = array([12, 23, 34, 45, 56])
+    
+    In []: C = array([[11, 12, 13, 14, 15],
+                      [21, 22, 23, 24, 25],
+                      [31, 32, 33, 34, 35],
+                      [41, 42, 43, 44, 45],
+                      [51, 52, 53, 54, 55]])
+    
+  #+end_src
+* Question 1
+  Change the last column of ~C~ to zeroes. 
+* Solution 1
+  #+begin_src python
+    In []:  C[:, -1] = 0
+  #+end_src
+* Question 2
+  Change ~A~ to ~[11, 12, 13, 14, 15]~. 
+* Solution 2
+  #+begin_src python
+    In []:  A[:] = [11, 12, 13, 14, 15]
+  #+end_src
+* squares.png
+  #+begin_latex
+    \begin{center}
+      \includegraphics[scale=0.6]{squares}    
+    \end{center}
+  #+end_latex
+* Question 3
+  - obtain ~[22, 23]~ from ~C~. 
+  - obtain ~[11, 21, 31, 41]~ from ~C~. 
+  - obtain ~[21, 31, 41, 0]~.   
+* Solution 3
+  #+begin_src python
+    In []:  C[1, 1:3]
+    In []:  C[0:4, 0]
+    In []:  C[1:5, 0]
+  #+end_src
+* Question 4
+  Obtain ~[[23, 24], [33, -34]]~ from ~C~
+* Solution 4
+  #+begin_src python
+    In []:  C[1:3, 2:4]
+  #+end_src
+* Question 5
+  Obtain the square in the center of the image
+* Solution 5
+  #+begin_src python
+    In []: imshow(I[75:225, 75:225])
+  #+end_src
+* Question 6
+  Obtain the following
+  #+begin_src python
+    [[12, 0], [42, 0]]
+    [[12, 13, 14], [0, 0, 0]]
+  #+end_src
+
+* Solution 6
+  #+begin_src python
+    In []: C[::3, 1::3]
+    In []: C[::4, 1:4]
+  #+end_src
+* Summary
+  You should now be able to --
+  - Manipulate single \& multi dimensional arrays
+      - Access and change individual elements 
+      - Access and change rows and columns 
+      - Slice and stride on arrays
+  - Read images into arrays and manipulate them.
+* Thank you!
+#+begin_latex
+  \begin{block}{}
+  \begin{center}
+  This spoken tutorial has been produced by the
+  \textcolor{blue}{FOSSEE} team, which is funded by the 
+  \end{center}
+  \begin{center}
+    \textcolor{blue}{National Mission on Education through \\
+      Information \& Communication Technology \\ 
+      MHRD, Govt. of India}.
+  \end{center}  
+  \end{block}
+#+end_latex
+
+
diff --git a/accessing_parts_of_arrays/slides.tex b/accessing_parts_of_arrays/slides.tex
new file mode 100644
index 0000000..a3e4c6d
--- /dev/null
+++ b/accessing_parts_of_arrays/slides.tex
@@ -0,0 +1,214 @@
+% Created 2010-11-02 Tue 17:47
+\documentclass[presentation]{beamer}
+\usepackage[latin1]{inputenc}
+\usepackage[T1]{fontenc}
+\usepackage{fixltx2e}
+\usepackage{graphicx}
+\usepackage{longtable}
+\usepackage{float}
+\usepackage{wrapfig}
+\usepackage{soul}
+\usepackage{textcomp}
+\usepackage{marvosym}
+\usepackage{wasysym}
+\usepackage{latexsym}
+\usepackage{amssymb}
+\usepackage{hyperref}
+\tolerance=1000
+\usepackage[english]{babel} \usepackage{ae,aecompl}
+\usepackage{mathpazo,courier,euler} \usepackage[scaled=.95]{helvet}
+\usepackage{listings}
+\lstset{language=Python, basicstyle=\ttfamily\bfseries,
+commentstyle=\color{red}\itshape, stringstyle=\color{darkgreen},
+showstringspaces=false, keywordstyle=\color{blue}\bfseries}
+\providecommand{\alert}[1]{\textbf{#1}}
+
+\title{Accessing parts of arrays}
+\author{FOSSEE}
+\date{}
+
+\usetheme{Antibes}\usecolortheme{lily}\useoutertheme{infolines}\setbeamercovered{transparent}
+\begin{document}
+
+\maketitle
+
+
+
+
+
+
+
+
+
+\begin{frame}
+\frametitle{Outline}
+\label{sec-1}
+
+\begin{itemize}
+\item Manipulating one and multi dimensional arrays
+\item Access and change individual elements
+\item Access and change rows and columns
+\item Slicing and striding on arrays to access chunks
+\item Read images into arrays and manipulations
+\end{itemize}
+\end{frame}
+\begin{frame}[fragile]
+\frametitle{Sample Arrays}
+\label{sec-2}
+
+\lstset{language=Python}
+\begin{lstlisting}
+In []: A = array([12, 23, 34, 45, 56])
+
+In []: C = array([[11, 12, 13, 14, 15],
+                  [21, 22, 23, 24, 25],
+                  [31, 32, 33, 34, 35],
+                  [41, 42, 43, 44, 45],
+                  [51, 52, 53, 54, 55]])
+\end{lstlisting}
+\end{frame}
+\begin{frame}
+\frametitle{Question 1}
+\label{sec-3}
+
+  Change the last column of \texttt{C} to zeroes. 
+\end{frame}
+\begin{frame}[fragile]
+\frametitle{Solution 1}
+\label{sec-4}
+
+\lstset{language=Python}
+\begin{lstlisting}
+In []:  C[:, -1] = 0
+\end{lstlisting}
+\end{frame}
+\begin{frame}
+\frametitle{Question 2}
+\label{sec-5}
+
+  Change \texttt{A} to \texttt{[11, 12, 13, 14, 15]}. 
+\end{frame}
+\begin{frame}[fragile]
+\frametitle{Solution 2}
+\label{sec-6}
+
+\lstset{language=Python}
+\begin{lstlisting}
+In []:  A[:] = [11, 12, 13, 14, 15]
+\end{lstlisting}
+\end{frame}
+\begin{frame}
+\frametitle{squares.png}
+\label{sec-7}
+
+    \begin{center}
+      \includegraphics[scale=0.6]{squares}    
+    \end{center}
+\end{frame}
+\begin{frame}
+\frametitle{Question 3}
+\label{sec-8}
+
+\begin{itemize}
+\item obtain \texttt{[22, 23]} from \texttt{C}.
+\item obtain \texttt{[11, 21, 31, 41]} from \texttt{C}.
+\item obtain \texttt{[21, 31, 41, 0]}.
+\end{itemize}
+\end{frame}
+\begin{frame}[fragile]
+\frametitle{Solution 3}
+\label{sec-9}
+
+\lstset{language=Python}
+\begin{lstlisting}
+In []:  C[1, 1:3]
+In []:  C[0:4, 0]
+In []:  C[1:5, 0]
+\end{lstlisting}
+\end{frame}
+\begin{frame}
+\frametitle{Question 4}
+\label{sec-10}
+
+  Obtain \texttt{[[23, 24], [33, -34]]} from \texttt{C}
+\end{frame}
+\begin{frame}[fragile]
+\frametitle{Solution 4}
+\label{sec-11}
+
+\lstset{language=Python}
+\begin{lstlisting}
+In []:  C[1:3, 2:4]
+\end{lstlisting}
+\end{frame}
+\begin{frame}
+\frametitle{Question 5}
+\label{sec-12}
+
+  Obtain the square in the center of the image
+\end{frame}
+\begin{frame}[fragile]
+\frametitle{Solution 5}
+\label{sec-13}
+
+\lstset{language=Python}
+\begin{lstlisting}
+In []: imshow(I[75:225, 75:225])
+\end{lstlisting}
+\end{frame}
+\begin{frame}[fragile]
+\frametitle{Question 6}
+\label{sec-14}
+
+  Obtain the following
+\lstset{language=Python}
+\begin{lstlisting}
+[[12, 0], [42, 0]]
+[[12, 13, 14], [0, 0, 0]]
+\end{lstlisting}
+\end{frame}
+\begin{frame}[fragile]
+\frametitle{Solution 6}
+\label{sec-15}
+
+\lstset{language=Python}
+\begin{lstlisting}
+In []: C[::3, 1::3]
+In []: C[::4, 1:4]
+\end{lstlisting}
+\end{frame}
+\begin{frame}
+\frametitle{Summary}
+\label{sec-16}
+
+  You should now be able to --
+\begin{itemize}
+\item Manipulate single \& multi dimensional arrays
+
+\begin{itemize}
+\item Access and change individual elements
+\item Access and change rows and columns
+\item Slice and stride on arrays
+\end{itemize}
+
+\item Read images into arrays and manipulate them.
+\end{itemize}
+\end{frame}
+\begin{frame}
+\frametitle{Thank you!}
+\label{sec-17}
+
+  \begin{block}{}
+  \begin{center}
+  This spoken tutorial has been produced by the
+  \textcolor{blue}{FOSSEE} team, which is funded by the 
+  \end{center}
+  \begin{center}
+    \textcolor{blue}{National Mission on Education through \\
+      Information \& Communication Technology \\ 
+      MHRD, Govt. of India}.
+  \end{center}  
+  \end{block}
+\end{frame}
+
+\end{document}
diff --git a/accessing_parts_of_arrays/slides.tex.orig b/accessing_parts_of_arrays/slides.tex.orig
new file mode 100644
index 0000000..91e8959
--- /dev/null
+++ b/accessing_parts_of_arrays/slides.tex.orig
@@ -0,0 +1,199 @@
+% Created 2010-11-03 Wed 15:37
+\documentclass[presentation]{beamer}
+\usetheme{Antibes}\usecolortheme{lily}\useoutertheme{infolines}\setbeamercovered{transparent}
+\usepackage[latin1]{inputenc}
+\usepackage[T1]{fontenc}
+\usepackage{graphicx}
+\usepackage{longtable}
+\usepackage{float}
+\usepackage{wrapfig}
+\usepackage{soul}
+\usepackage{amssymb}
+\usepackage{hyperref}
+\usepackage[english]{babel} \usepackage{ae,aecompl}
+\usepackage{mathpazo,courier,euler} \usepackage[scaled=.95]{helvet}
+\usepackage{listings}
+\lstset{language=Python, basicstyle=\ttfamily\bfseries,
+commentstyle=\color{red}\itshape, stringstyle=\color{darkgreen},
+showstringspaces=false, keywordstyle=\color{blue}\bfseries}
+
+\title{Accessing parts of arrays}
+\author{FOSSEE}
+\date{}
+
+\begin{document}
+
+\maketitle
+
+
+
+
+
+
+
+
+
+\begin{frame}
+\frametitle{Outline}
+\label{sec-1}
+
+\begin{itemize}
+\item Manipulating one and multi dimensional arrays
+\item Access and change individual elements
+\item Access and change rows and columns
+\item Slicing and striding on arrays to access chunks
+\item Read images into arrays and manipulations
+\end{itemize}
+\end{frame}
+\begin{frame}[fragile]
+\frametitle{Sample Arrays}
+\label{sec-2}
+
+\begin{verbatim}
+In []: A = array([12, 23, 34, 45, 56])
+
+In []: C = array([[11, 12, 13, 14, 15],
+                  [21, 22, 23, 24, 25],
+                  [31, 32, 33, 34, 35],
+                  [41, 42, 43, 44, 45],
+                  [51, 52, 53, 54, 55]])
+\end{verbatim}
+\end{frame}
+\begin{frame}
+\frametitle{Question 1}
+\label{sec-3}
+
+  Change the last column of \texttt{C} to zeroes. 
+\end{frame}
+\begin{frame}[fragile]
+\frametitle{Solution 1}
+\label{sec-4}
+
+\begin{verbatim}
+In []:  C[:, -1] = 0
+\end{verbatim}
+\end{frame}
+\begin{frame}
+\frametitle{Question 2}
+\label{sec-5}
+
+  Change \texttt{A} to \texttt{[11, 12, 13, 14, 15]}. 
+\end{frame}
+\begin{frame}[fragile]
+\frametitle{Solution 2}
+\label{sec-6}
+
+\begin{verbatim}
+In []:  A[:] = [11, 12, 13, 14, 15]
+\end{verbatim}
+\end{frame}
+\begin{frame}
+\frametitle{squares.png}
+\label{sec-7}
+
+    \begin{center}
+      \includegraphics[scale=0.6]{squares}    
+    \end{center}
+\end{frame}
+\begin{frame}
+\frametitle{Question 3}
+\label{sec-8}
+
+\begin{itemize}
+\item obtain \texttt{[22, 23]} from \texttt{C}.
+\item obtain \texttt{[11, 21, 31, 41]} from \texttt{C}.
+\item obtain \texttt{[21, 31, 41, 0]}.
+\end{itemize}
+\end{frame}
+\begin{frame}[fragile]
+\frametitle{Solution 3}
+\label{sec-9}
+
+\begin{verbatim}
+In []:  C[1, 1:3]
+In []:  C[0:4, 0]
+In []:  C[1:5, 0]
+\end{verbatim}
+\end{frame}
+\begin{frame}
+\frametitle{Question 4}
+\label{sec-10}
+
+  Obtain \texttt{[[23, 24], [33, -34]]} from \texttt{C}
+\end{frame}
+\begin{frame}[fragile]
+\frametitle{Solution 4}
+\label{sec-11}
+
+\begin{verbatim}
+In []:  C[1:3, 2:4]
+\end{verbatim}
+\end{frame}
+\begin{frame}
+\frametitle{Question 5}
+\label{sec-12}
+
+  Obtain the square in the center of the image
+\end{frame}
+\begin{frame}[fragile]
+\frametitle{Solution 5}
+\label{sec-13}
+
+\begin{verbatim}
+In []: imshow(I[75:225, 75:225])
+\end{verbatim}
+\end{frame}
+\begin{frame}[fragile]
+\frametitle{Question 6}
+\label{sec-14}
+
+  Obtain the following
+\begin{verbatim}
+[[12, 0], [42, 0]]
+[[12, 13, 14], [0, 0, 0]]
+\end{verbatim}
+\end{frame}
+\begin{frame}[fragile]
+\frametitle{Solution 6}
+\label{sec-15}
+
+\begin{verbatim}
+In []: C[::3, 1::3]
+In []: C[::4, 1:4]
+\end{verbatim}
+\end{frame}
+\begin{frame}
+\frametitle{Summary}
+\label{sec-16}
+
+  You should now be able to --
+\begin{itemize}
+\item Manipulate single \& multi dimensional arrays
+
+\begin{itemize}
+\item Access and change individual elements
+\item Access and change rows and columns
+\item Slice and stride on arrays
+\end{itemize}
+
+\item Read images into arrays and manipulate them.
+\end{itemize}
+\end{frame}
+\begin{frame}
+\frametitle{Thank you!}
+\label{sec-17}
+
+  \begin{block}{}
+  \begin{center}
+  This spoken tutorial has been produced by the
+  \textcolor{blue}{FOSSEE} team, which is funded by the 
+  \end{center}
+  \begin{center}
+    \textcolor{blue}{National Mission on Education through \\
+      Information \& Communication Technology \\ 
+      MHRD, Govt. of India}.
+  \end{center}  
+  \end{block}
+\end{frame}
+
+\end{document}
diff --git a/accessing_parts_of_arrays/squares.png b/accessing_parts_of_arrays/squares.png
new file mode 100644
index 0000000..ee102e6
--- /dev/null
+++ b/accessing_parts_of_arrays/squares.png
diff --git a/accessing_parts_of_arrays/tagore-einstein.png b/accessing_parts_of_arrays/tagore-einstein.png
new file mode 100644
index 0000000..0841dd0
--- /dev/null
+++ b/accessing_parts_of_arrays/tagore-einstein.png