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[exercises] update exercise 3/4

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Jan Grewe 2018-10-17 11:23:05 +02:00
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26
programming/exercises/boolean_logical_indexing.tex
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@ -13,8 +13,8 @@
%%%%% text size %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% %%%%% text size %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\usepackage[left=20mm,right=20mm,top=25mm,bottom=25mm]{geometry} \usepackage[left=20mm,right=20mm,top=25mm,bottom=25mm]{geometry}
\pagestyle{headandfoot} \header{{\bfseries\large \"Ubung \pagestyle{headandfoot} \header{{\bfseries\large Exercise 4
3}}{{\bfseries\large Boolean Expressions and logical indexing}}{{\bfseries\large 24. Oktober, 2017}} }}{{\bfseries\large Boolean Expressions and logical indexing}}{{\bfseries\large 23. Oktober, 2018}}
\firstpagefooter{Dr. Jan Grewe}{Phone: 29 74588}{Email: \firstpagefooter{Dr. Jan Grewe}{Phone: 29 74588}{Email:
jan.grewe@uni-tuebingen.de} \runningfooter{}{\thepage}{} jan.grewe@uni-tuebingen.de} \runningfooter{}{\thepage}{}
@ -35,12 +35,12 @@
Abteilung Neuroethologie \hfill --- \hfill Institut f\"ur Neurobiologie \hfill --- \hfill \includegraphics[width=0.28\textwidth]{UT_WBMW_Black_RGB} \\ Abteilung Neuroethologie \hfill --- \hfill Institut f\"ur Neurobiologie \hfill --- \hfill \includegraphics[width=0.28\textwidth]{UT_WBMW_Black_RGB} \\
\end{center} \end{center}
The exercises are meant for self-monitoring, revision of the lecture The exercises are meant for self-monitoring and revision of the
topic. You should try to solve them on your own. Your solution should lecture. You should try to solve them on your own. Your solution
be submitted as a single script (m-file) in the Ilias system. Each should be submitted as a single script (m-file) in the Ilias
task should be solved in its own ``cell''. Each cell must be system. Each task should be solved in its own ``cell''. Each cell must
executable on its own. The file should be named according to the following pattern: be executable on its own. The file should be named according to the
``variables\_datatypes\_\{lastname\}.m'' benannt werden following pattern: ``variables\_datatypes\_\{lastname\}.m''
(e.g. variables\_datentypes\_mueller.m). (e.g. variables\_datentypes\_mueller.m).
\section{Boolean expressions} \section{Boolean expressions}
@ -62,10 +62,10 @@ executable on its own. The file should be named according to the following patte
\part Execute and explain: \verb+bitand(10, 8)+ \part Execute and explain: \verb+bitand(10, 8)+
\part Execute and explain: \verb+bitor(10, 8)+ \part Execute and explain: \verb+bitor(10, 8)+
\end{parts} \end{parts}
\item Implemen the following Boolean expressions. Test using randomly selected integer values for \verb+x+ and \verb+y+. \item Implement the following Boolean expressions. Test using randomly selected integer values for \verb+x+ and \verb+y+.
\begin{parts} \begin{parts}
\part The result should be \verb+true+ if \verb+x+ greater than \verb+y+ and the sum of \verb+x+ and \verb+y+ is not less than 100. \part The result should be \verb+true+ if \verb+x+ greater than \verb+y+ and the sum of \verb+x+ and \verb+y+ is not less than 100.
\part The result shoudl be \verb+true+ if \verb+x+ and \verb+y+ are not equal zero or \verb+x+ and \verb+y+ are equal. \part The result should be \verb+true+ if \verb+x+ and \verb+y+ are not equal zero or \verb+x+ and \verb+y+ are equal.
\end{parts} \end{parts}
\end{questions} \end{questions}
@ -74,12 +74,12 @@ executable on its own. The file should be named according to the following patte
Boolean expressions can be used to select elements of vectors or Boolean expressions can be used to select elements of vectors or
matrices that match in certain criteria. This process is called matrices that match in certain criteria. This process is called
logical indexing. \emph{logical indexing}.
\begin{questions} \begin{questions}
\question Given are the vectors \verb+x = (1:10)+ and \question Given are the vectors \verb+x = (1:10)+ and
\verb+y = [3 1 5 6 8 2 9 4 7 0]+. Try to understand the results of \verb+y = [3 1 5 6 8 2 9 4 7 0]+. Try to understand the results of
the following commands. Explain. the following commands and explain.
\begin{parts} \begin{parts}
\part \verb+x < 5+ \part \verb+x < 5+
\part \verb+x( x < 5) )+ \part \verb+x( x < 5) )+
@ -90,7 +90,7 @@ logical indexing.
\question Test the random number generator: \question Test the random number generator:
\begin{parts} \begin{parts}
\part Create a 100x100 2-D matrix that is filled with random numbers in the range 0 to 100 (\verb+randi+). Replace the elements according to these rules: \verb+x < 33+ to 0, \part Create a $100 \times 100$ 2-D matrix that is filled with random numbers in the range 0 to 100. Replace the elements according to these rules: \verb+x < 33+ to 0,
\verb+x >= 33 and x < 66+ to 1 and all \verb+x >= 66+ to 2. \verb+x >= 33 and x < 66+ to 1 and all \verb+x >= 66+ to 2.
\part Count the number of elements in each class using Boolean expressions (\verb+sum+ can be used to count the matches). \part Count the number of elements in each class using Boolean expressions (\verb+sum+ can be used to count the matches).
\end{parts} \end{parts}

44
programming/exercises/matrices.tex
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@ -36,13 +36,13 @@
Neuroethology \hfill --- \hfill Institute for Neurobiology \hfill --- \hfill \includegraphics[width=0.28\textwidth]{UT_WBMW_Black_RGB} \\ Neuroethology \hfill --- \hfill Institute for Neurobiology \hfill --- \hfill \includegraphics[width=0.28\textwidth]{UT_WBMW_Black_RGB} \\
\end{center} \end{center}
The exercises are meant for self-monitoring, revision of the lecture The exercises are meant for self-monitoring and revision of the
topic. You should try to solve them on your own. Your solution should lecture. You should try to solve them on your own. Your solution
be submitted as a single script (m-file) in the Ilias system. Each should be submitted as a single script (m-file) in the Ilias
task should be solved in its own ``cell''. Each cell must be system. Each task should be solved in its own ``cell''. Each cell must
executable on its own. The file should be named according to the following pattern: be executable on its own. The file should be named according to the
``variables\_datatypes\_\{lastname\}.m'' benannt werden following pattern:
(e.g. variables\_datentypes\_mueller.m). ``matrices\_\{lastname\}.m''(e.g. matrices\_mueller.m).
\begin{questions} \begin{questions}
@ -58,27 +58,28 @@ executable on its own. The file should be named according to the following patte
\begin{solution} \begin{solution}
\code{disp(size(x, 1))}\\\code{disp(size(x, 2))} \code{disp(size(x, 1))}\\\code{disp(size(x, 2))}
\end{solution} \end{solution}
\part Retrieve the element at the position 3rd line, 2nd column. \part Copy the content at the position 3rd line, 2nd column to a new variable.
\begin{solution} \begin{solution}
\code{x(3,2)} \code{c = x(3, 2)}
\end{solution} \end{solution}
\part Print all elements of the 1st, 2nd and 3rd line. \part Display all elements of the 1st, 2nd and 3rd line.
\begin{solution} \begin{solution}
\code{disp(x([1 2 3], :));} \code{disp(x([1 2 3], :));}
\end{solution} \end{solution}
\part Print all elements of the 1st, 2nd, and 3rd column. \part Display all elements of the 1st, 2nd, and 3rd column.
\begin{solution} \begin{solution}
\code{disp(x(:, 1))\\ disp(x(:, 2))\\ disp(x(:, 3))} \code{disp(x(:, 1))\\ disp(x(:, 2))\\ disp(x(:, 3))}
\end{solution} \end{solution}
\part Increment all elements of the 2nd line and the 3rd column about 1. \part Increment all elements of the 2nd line and the 3rd column about 1 (reassign the result to the respective elements).
\begin{solution} \begin{solution}
\code{x(2,3) = x(2,3) + 1;} \code{x(2,:) = x(2,:) + 1;}\\
\code{x(:,3) = x(:,3) + 1;}
\end{solution} \end{solution}
\part Subtract five from all elements of the 1st line. \part Subtract five from all elements of the 1st line.
\begin{solution} \begin{solution}
\code{x(1,:) = x(1,:) - 5;} \code{x(1,:) = x(1,:) - 5;}
\end{solution} \end{solution}
\part Multiply all elements of the 3rd column with 2. \part Multiply all elements of the 3rd column by 2.
\begin{solution} \begin{solution}
\code{x(:,3) = x(:,3) .* 2;} \code{x(:,3) = x(:,3) .* 2;}
\end{solution} \end{solution}
@ -87,7 +88,7 @@ executable on its own. The file should be named according to the following patte
\question Create a $5 \times 5$ matrix \code{M} that contains random numbers (use the function \question Create a $5 \times 5$ matrix \code{M} that contains random numbers (use the function
\verb+randn()+. Use the help to find out what it does). \verb+randn()+. Use the help to find out what it does).
\begin{parts} \begin{parts}
\part Print the element at the position 2nd line and 3rd column. \part Display the content of \code{M} at position 2nd line and 3rd column.
\begin{solution} \begin{solution}
\code{M = randn(5, 5);} \code{M = randn(5, 5);}
\code{disp(M(2,3))} \code{disp(M(2,3))}
@ -124,7 +125,7 @@ executable on its own. The file should be named according to the following patte
\code{sum(M(:))} \code{sum(M(:))}
\end{solution} \end{solution}
\part Exchange all elements of the 2nd with those of the 4th line. \part Replace all elements of the 2nd line with those of the 4th line.
\begin{solution} \begin{solution}
\code{M(2,:) = M(4,:)} \code{M(2,:) = M(4,:)}
\end{solution} \end{solution}
@ -158,7 +159,7 @@ executable on its own. The file should be named according to the following patte
\code{x(randi(100, 50, 1)])} \code{x(randi(100, 50, 1)])}
\end{solution} \end{solution}
\part Is there an advantage to use the linear indexing? \part Can you imaging an advantage of using linear indexing instead of subscript indexing?
\begin{solution} \begin{solution}
Die Matrize ist 2-dimensional. Wenn mit dem subscript index Die Matrize ist 2-dimensional. Wenn mit dem subscript index
zugegriffen werden soll, dann muss auf die Dimensionen zugegriffen werden soll, dann muss auf die Dimensionen
@ -175,8 +176,10 @@ executable on its own. The file should be named according to the following patte
\end{parts} \end{parts}
\question Create the three variables \verb+x = [1 5 9]+ and \question Create three variables \verb+x = [1 5 9]+ and
\verb+y = [7 1 5]+ and \verb+M = [3 1 6; 5 2 7]+. Which of the following commands will pass? Which command will not? If not, why? Test your predictions. \verb+y = [7 1 5]+ and \verb+M = [3 1 6; 5 2 7]+. Which of the
following commands will pass? Which command will fail? If it fails,
why? Test your predictions.
\begin{parts} \begin{parts}
\part \code{x + y} \part \code{x + y}
\begin{solution} \begin{solution}
@ -209,7 +212,8 @@ executable on its own. The file should be named according to the following patte
\end{solution} \end{solution}
\end{parts} \end{parts}
\question Create a 3-D matrix from two 2-D matrices. Use the function cat (check the help to learn its usage). \question Create a 3-D matrix from two 2-D matrices. Use the
function \code{cat} (check the help to learn its usage).
\begin{parts} \begin{parts}
\part Select all elements of the first ``page'' (index 1, 3. dimension). \part Select all elements of the first ``page'' (index 1, 3. dimension).
\begin{solution} \begin{solution}