day1/session6.tex
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   186 \end{frame}
   186 \end{frame}
   187 
   187 
   188 \subsection{Exercises}
   188 \subsection{Exercises}
   189 
   189 
   190 \begin{frame}[fragile]
   190 \begin{frame}[fragile]
   191 \frametitle{Problem 1}
   191 \frametitle{Problem}
   192 Given the matrix:\\
       
   193 \begin{center}
       
   194 $\begin{bmatrix}
       
   195 -2 & 2 & 3\\
       
   196  2 & 1 & 6\\
       
   197 -1 &-2 & 0\\
       
   198 \end{bmatrix}$
       
   199 \end{center}
       
   200 Find:
       
   201 \begin{itemize}
       
   202   \item[i] Transpose
       
   203   \item[ii]Inverse
       
   204   \item[iii]Determinant
       
   205   \item[iv] Eigenvalues and Eigen vectors
       
   206   \item[v] Singular Value decomposition
       
   207 \end{itemize}
       
   208 \end{frame}
       
   209 
       
   210 \begin{frame}[fragile]
       
   211 \frametitle{Problem 2}
       
   212 Given 
       
   213 \begin{center}
       
   214 A = 
       
   215 $\begin{bmatrix}
       
   216 -3 & 1 & 5 \\
       
   217 1 & 0 & -2 \\
       
   218 5 & -2 & 4 \\
       
   219 \end{bmatrix}$
       
   220 , B = 
       
   221 $\begin{bmatrix}
       
   222 0 & 9 & -12 \\
       
   223 -9 & 0 & 20 \\
       
   224 12 & -20 & 0 \\
       
   225 \end{bmatrix}$
       
   226 \end{center}
       
   227 Find:
       
   228 \begin{itemize}
       
   229   \item[i] Sum of A and B
       
   230   \item[ii]Elementwise Product of A and B
       
   231   \item[iii] Matrix product of A and B
       
   232 \end{itemize}
       
   233 \end{frame}
       
   234 
       
   235 \begin{frame}[fragile]
       
   236 \frametitle{Solution}
       
   237 Sum: 
       
   238 $\begin{bmatrix}
       
   239 -3 & 10 & 7 \\
       
   240 -8 & 0 & 18 \\
       
   241 17 & -22 & 4 \\
       
   242 \end{bmatrix}$
       
   243 ,\\ Elementwise Product:
       
   244 $\begin{bmatrix}
       
   245 0 & 9 & -60 \\
       
   246 -9 & 0 & -40 \\
       
   247 60 & 40 & 0 \\
       
   248 \end{bmatrix}$
       
   249 ,\\ Matrix product:
       
   250 $\begin{bmatrix}
       
   251 51 & -127 & 56 \\
       
   252 -24 & 49 & -12 \\
       
   253 66 & -35 & -100 \\
       
   254 \end{bmatrix}$
       
   255 \end{frame}
       
   256 
       
   257 \begin{frame}[fragile]
       
   258 \frametitle{Problem 3}
       
   259 Solve the set of equations:
   192 Solve the set of equations:
   260 \begin{align*}
   193 \begin{align*}
   261   x + y + 2z -w & = 3\\
   194   x + y + 2z -w & = 3\\
   262   2x + 5y - z - 9w & = -3\\
   195   2x + 5y - z - 9w & = -3\\
   263   2x + y -z + 3w & = -11 \\
   196   2x + y -z + 3w & = -11 \\
   372 %% \end{lstlisting}
   305 %% \end{lstlisting}
   373 %% \end{small}
   306 %% \end{small}
   374 %% \end{frame}
   307 %% \end{frame}
   375 
   308 
   376 \section{ODEs}
   309 \section{ODEs}
   377 \begin{frame}[fragile]
   310 
   378 \frametitle{ODE Integration}
   311 \begin{frame}[fragile]
       
   312 \frametitle{Solving ODEs using SciPy}
       
   313 \begin{itemize}
       
   314 \item Let's consider the spread of an epidemic in a population
       
   315 \item $\frac{dy}{dt} = ky(L-y)$ gives the spread of the disease
       
   316 \item L is the total population.
       
   317 \item Use L = 25000, k = 0.00003, y(0) = 250
       
   318 \item Define a function as below
       
   319 \end{itemize}
       
   320 \begin{lstlisting}
       
   321 In []: def epid(y, t):
       
   322   ....     k, L = 0.00003, 25000
       
   323   ....     return k*y*(L-y)
       
   324   ....
       
   325 \end{lstlisting}
       
   326 \end{frame}
       
   327 
       
   328 \begin{frame}[fragile]
       
   329 \frametitle{Solving ODEs using SciPy \ldots}
       
   330 \begin{lstlisting}
       
   331 In []: t = arange(0, 12, 0.2)
       
   332 
       
   333 In []: y = odeint(epid, 250, t)
       
   334 
       
   335 In []: plot(t, y)
       
   336 \end{lstlisting}
       
   337 %Insert Plot
       
   338 \end{frame}
       
   339 
       
   340 \begin{frame}[fragile]
       
   341 \frametitle{ODEs - Simple Pendulum}
   379 We shall use the simple ODE of a simple pendulum. 
   342 We shall use the simple ODE of a simple pendulum. 
   380 \begin{equation*}
   343 \begin{equation*}
   381 \ddot{\theta} = -\frac{g}{L}sin(\theta)
   344 \ddot{\theta} = -\frac{g}{L}sin(\theta)
   382 \end{equation*}
   345 \end{equation*}
   383 \begin{itemize}
   346 \begin{itemize}
   390  \theta = \theta_0(10^o)\quad & \&\quad  \omega = 0\ (Initial\ values)\nonumber 
   353  \theta = \theta_0(10^o)\quad & \&\quad  \omega = 0\ (Initial\ values)\nonumber 
   391 \end{align}
   354 \end{align}
   392 \end{frame}
   355 \end{frame}
   393 
   356 
   394 \begin{frame}[fragile]
   357 \begin{frame}[fragile]
   395 \frametitle{Solving ODEs using SciPy}
   358 \frametitle{ODEs - Simple Pendulum \ldots}
   396 \begin{itemize}
   359 \begin{itemize}
   397 \item We use the \typ{odeint} function from scipy to do the integration
   360 \item Use \typ{odeint} to do the integration
   398 \item Define a function as below
       
   399 \end{itemize}
   361 \end{itemize}
   400 \begin{lstlisting}
   362 \begin{lstlisting}
   401 In []: def pend_int(initial, t):
   363 In []: def pend_int(initial, t):
   402   ....     theta, omega = initial
   364   ....     theta, omega = initial
   403   ....     g, L = 9.81, 0.2
   365   ....     g, L = 9.81, 0.2
   406   ....
   368   ....
   407 \end{lstlisting}
   369 \end{lstlisting}
   408 \end{frame}
   370 \end{frame}
   409 
   371 
   410 \begin{frame}[fragile]
   372 \begin{frame}[fragile]
   411 \frametitle{Solving ODEs using SciPy \ldots}
   373 \frametitle{ODEs - Simple Pendulum \ldots}
   412 \begin{itemize}
   374 \begin{itemize}
   413 \item \typ{t} is the time variable \\ 
   375 \item \typ{t} is the time variable \\ 
   414 \item \typ{initial} has the initial values
   376 \item \typ{initial} has the initial values
   415 \end{itemize}
   377 \end{itemize}
   416 \begin{lstlisting}
   378 \begin{lstlisting}
   418 In []: initial = [10*2*pi/360, 0]
   380 In []: initial = [10*2*pi/360, 0]
   419 \end{lstlisting} 
   381 \end{lstlisting} 
   420 \end{frame}
   382 \end{frame}
   421 
   383 
   422 \begin{frame}[fragile]
   384 \begin{frame}[fragile]
   423 \frametitle{Solving ODEs using SciPy \ldots}
   385 \frametitle{ODEs - Simple Pendulum \ldots}
   424 %%\begin{small}
   386 %%\begin{small}
   425 \typ{In []: from scipy.integrate import odeint}
   387 \typ{In []: from scipy.integrate import odeint}
   426 %%\end{small}
   388 %%\end{small}
   427 \begin{lstlisting}
   389 \begin{lstlisting}
   428 In []: pend_sol = odeint(pend_int, 
   390 In []: pend_sol = odeint(pend_int,