day1/exercises.tex
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    76 \title[Exercises]{Exercises}
    76 \title[Exercises]{Exercises}
    77 
    77 
    78 \author[FOSSEE] {FOSSEE}
    78 \author[FOSSEE] {FOSSEE}
    79 
    79 
    80 \institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay}
    80 \institute[IIT Bombay] {Department of Aerospace Engineering\\IIT Bombay}
    81 \date[] {14 December, 2009\\Day 1, Session 5}
    81 \date[] {11 January, 2010\\Day 1, Session 5}
    82 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    82 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
    83 
    83 
    84 %\pgfdeclareimage[height=0.75cm]{iitmlogo}{iitmlogo}
    84 %\pgfdeclareimage[height=0.75cm]{iitmlogo}{iitmlogo}
    85 %\logo{\pgfuseimage{iitmlogo}}
    85 %\logo{\pgfuseimage{iitmlogo}}
    86 
    86 
   109 \begin{frame}
   109 \begin{frame}
   110   \titlepage
   110   \titlepage
   111 \end{frame}
   111 \end{frame}
   112 
   112 
   113 
   113 
       
   114 \begin{frame}[fragile]
       
   115   \frametitle{Problem 1}
       
   116   \begin{columns}
       
   117     \column{0.5\textwidth}
       
   118     \hspace*{-0.5in}
       
   119     \includegraphics[height=2in, interpolate=true]{data/L-Tsq.png}
       
   120     \column{0.45\textwidth}
       
   121     \begin{block}{Example code}
       
   122     \tiny
       
   123     \begin{lstlisting}
       
   124 l = []
       
   125 t = []
       
   126 for line in open('pendulum.txt'):
       
   127     point = line.split()
       
   128     l.append(float(point[0]))
       
   129     t.append(float(point[1]))
       
   130 tsq = []
       
   131 for time in t:
       
   132     tsq.append(time*time)
       
   133 plot(l, tsq, '.')
       
   134     \end{lstlisting}
       
   135     \end{block}
       
   136   \end{columns}
       
   137   \begin{block}{Problem Statement}
       
   138     Tweak above code to plot data in file 'location.txt'.
       
   139   \end{block}
       
   140 \end{frame}
       
   141 
   114 \begin{frame}
   142 \begin{frame}
   115   \frametitle{Problem 1}
   143   \frametitle{Problem 1 cont...}
   116   \begin{itemize}
   144   \begin{itemize}
   117   \item Open file 'pos.txt', it has X and Y Coordinate of a particle under motion
       
   118   \item Plot X vs Y Graph.
       
   119   \item Label both the axes.
   145   \item Label both the axes.
   120   \item What kind of motion is this?
   146   \item What kind of motion is this?
   121   \item Title the graph accordingly.
   147   \item Title the graph accordingly.
   122   \item Annotate the position where vertical velocity is zero.
   148   \item Annotate the position where vertical velocity is zero.
   123   \end{itemize}
   149   \end{itemize}
   124 \end{frame}
   150 \end{frame}
   125 
   151 
   126 \begin{frame}
   152 \begin{frame}[fragile]
   127   \frametitle{Problem 2}
   153   \frametitle{Problem 2}
   128 Write a Program that plots a regular n-gon(Let n = 5).
   154   \begin{columns}
   129 \end{frame}
   155     \column{0.5\textwidth}
       
   156     \hspace*{-0.5in}
       
   157     \includegraphics[height=2in, interpolate=true]{data/points}
       
   158     \column{0.45\textwidth}
       
   159     \begin{block}{Line between two points}
       
   160     \tiny
       
   161     \begin{lstlisting}
       
   162 In []: x = [1, 5]
       
   163 In []: y = [1, 4]
       
   164 In []: plot(x, y)
       
   165     \end{lstlisting}
       
   166     \end{block}
       
   167   \end{columns}
       
   168   Line can be plotted using arrays of coordinates.
       
   169   \pause
       
   170   \begin{block}{Problem statement}
       
   171     Write a Program that plots a regular n-gon(Let n = 5).
       
   172   \end{block}  
       
   173 \end{frame}
       
   174 
   130 
   175 
   131 \begin{frame}[fragile]
   176 \begin{frame}[fragile]
   132   \frametitle{Problem 3}
   177   \frametitle{Problem 3}
       
   178   \begin{columns}
       
   179     \column{0.5\textwidth}
       
   180     \hspace*{-0.5in}
       
   181     \includegraphics[height=2in, interpolate=true]{data/damp}
       
   182     \column{0.45\textwidth}
       
   183     \begin{block}{Damped Oscillation}
       
   184     \tiny
       
   185     \begin{lstlisting}
       
   186 In []: x = linspace(0, 4*pi)
       
   187 In []: plot(x, exp(x/10)*sin(x))
       
   188     \end{lstlisting}
       
   189     \end{block}
       
   190   \end{columns}
       
   191 \end{frame}
       
   192 
       
   193 \begin{frame}[fragile]
       
   194   \frametitle{Problem 3 cont...}
   133 Create a sequence of images in which the damped oscillator($e^{x/10}sin(x)$) slowly evolves over time.
   195 Create a sequence of images in which the damped oscillator($e^{x/10}sin(x)$) slowly evolves over time.
   134 \begin{columns}
   196 \begin{columns}
   135 \column{0.35\textwidth}
   197 \column{0.35\textwidth}
   136 \includegraphics[width=1.5in,height=1.5in, interpolate=true]{data/plot2}
   198 \includegraphics[width=1.5in,height=1.5in, interpolate=true]{data/plot2}
   137 \column{0.35\textwidth}
   199 \column{0.35\textwidth}
   145 savefig('plot'+str(i)+'.png') #i is int variable  
   207 savefig('plot'+str(i)+'.png') #i is int variable  
   146   \end{lstlisting}  
   208   \end{lstlisting}  
   147 \end{block}
   209 \end{block}
   148 \end{frame}
   210 \end{frame}
   149 
   211 
       
   212 \begin{frame}[fragile]
       
   213   \frametitle{Problem 4}
       
   214   \begin{lstlisting}
       
   215 In []: x = imread('smoothing.png')
       
   216 In []: x.shape
       
   217 Out[]: (256, 256)
       
   218 In []: imshow(x,cmap=cm.gray)
       
   219   \end{lstlisting}
       
   220 \emphbar{Replace each pixel with mean of neighboring pixels}
       
   221   \begin{center}
       
   222   \includegraphics[height=1in, interpolate=true]{data/neighbour}
       
   223   \end{center}
       
   224 \end{frame}
       
   225 
   150 \begin{frame}
   226 \begin{frame}
   151   \frametitle{Problem 4}
   227   \begin{center}
   152   Legendre polynomials $P_n(x)$ are defined by the following recurrence relation
   228     \includegraphics[height=3in, interpolate=true]{data/smoothing}    
   153 
   229   \end{center}
   154 \center{$(n+1)P_{n+1}(x) - (2n+1)xP_n(x) + nP_{n-1}(x) = 0$}\\
   230 \end{frame}
   155 
   231 
   156 with $P_0(x) = 1$, $P_1(x) = x$ and $P_2(x) = (3x^2 - 1)/2$. Compute the next three 
   232 \begin{frame}[fragile]
   157    Legendre polynomials and plot all 6 over the interval [-1,1].
   233   \frametitle{Problem 4: Approach}
   158 \end{frame}
   234   For \typ{y} being resultant image:
       
   235   \begin{lstlisting}
       
   236 y[1, 1] = x[0, 1]/4 + x[1, 0]/4 
       
   237           + x[2, 1]/4 + x[1, 2]/4    
       
   238   \end{lstlisting}
       
   239    \begin{columns}
       
   240     \column{0.45\textwidth}
       
   241     \hspace*{-0.5in}
       
   242     \includegraphics[height=1.5in, interpolate=true]{data/smoothing}
       
   243     \column{0.45\textwidth}
       
   244     \hspace*{-0.5in}
       
   245     \includegraphics[height=1.5in, interpolate=true]{data/after-filter}
       
   246   \end{columns}
       
   247    \begin{block}{Hint:}
       
   248      Use array Slicing.
       
   249    \end{block}
       
   250 \end{frame}
       
   251 
       
   252 \begin{frame}[fragile]
       
   253   \frametitle{Solution}
       
   254   \begin{lstlisting}
       
   255 In []: y = zeros_like(x)
       
   256 In []: y[1:-1,1:-1] = x[:-2,1:-1]/4+
       
   257                       x[2:,1:-1]/4+
       
   258                       x[1:-1,2:]/4+
       
   259                       x[1:-1,:-2]/4
       
   260 In []: imshow(y,cmap=cm.gray)
       
   261   \end{lstlisting}
       
   262 \end{frame}
       
   263 
       
   264 
   159 \end{document}
   265 \end{document}
       
   266 
       
   267 %% \begin{frame}
       
   268 %%   \frametitle{Problem 4}
       
   269 %%   Legendre polynomials $P_n(x)$ are defined by the following recurrence relation
       
   270 
       
   271 %% \center{$(n+1)P_{n+1}(x) - (2n+1)xP_n(x) + nP_{n-1}(x) = 0$}\\
       
   272 
       
   273 %% with $P_0(x) = 1$, $P_1(x) = x$ and $P_2(x) = (3x^2 - 1)/2$. Compute the next three 
       
   274 %%    Legendre polynomials and plot all 6 over the interval [-1,1].
       
   275 %% \end{frame}
   160 
   276 
   161 %% \begin{frame}[fragile] 
   277 %% \begin{frame}[fragile] 
   162 %% \frametitle{Problem Set 5}
   278 %% \frametitle{Problem Set 5}
   163 %%   \begin{columns}
   279 %%   \begin{columns}
   164 %%     \column{0.6\textwidth}
   280 %%     \column{0.6\textwidth}