diff --git a/plotting/lecture/plotting.tex b/plotting/lecture/plotting.tex
index 56af0eb..803fa8f 100644
--- a/plotting/lecture/plotting.tex
+++ b/plotting/lecture/plotting.tex
@@ -191,19 +191,20 @@ the data was changed or the same kind of plot has to be created for a
 number of datasets.
 
 \begin{important}[Why manual editing should be avoided.]
-  On first glance the manual editing of a figure using common tools
-  like Corel draw, Illustrator, etc.\,appears some much more
-  convenient and less complex. This, however, is not entirely
-  true. What if the figure has to be re-drawn or updated? Then the
-  editing work starts all over again. Rather, there is a great risk
-  associated with this approach. Axes are shifted, fonts have not been
-  embedded into the final document, annotations have been copy pasted
-  between figures and are not valid. All of these mistakes can be
-  found in publications and then require an erratum, which is not
+  On first glance the manual editing of a figure using tools such as
+  Corel draw, Illustrator, etc.\,appears much more convenient and less
+  complex than coding everything into the analysis scripts. This,
+  however, is not entirely true. What if the figure has to be re-drawn
+  or updated? Then the editing work starts all over again. Rather,
+  there is a great risk associated with the manual editing
+  approach. Axes may be shifted, fonts have not been embedded into the
+  final document, annotations have been copy pasted between figures
+  and are not valid. All of these mistakes can be found in
+  publications and then require an erratum, which is not
   desirable. Even if it appears more cumbersome in the beginning one
   should always try to create publication-ready figures directly from
-  the data analysis tool using scripts or functions to properly
-  layout the plot.
+  the data analysis tool using scripts or functions to properly layout
+  the plot.
 \end{important}
 
 \subsection{Simple plotting}
@@ -259,6 +260,12 @@ additional options consult the help.
   \end{tabular}
 \end{table}
 
+The following listing shows a simple line plot with axis labeling and a title
+
+\lstinputlisting[caption={A simple plot showing a sinewave.},
+  label=niceplotlisting]{simple_plot.m}
+
+
 \subsection{Changing properties of a line plot}
 
 The properties of line plots can be changed by passing more arguments
diff --git a/programming/exercises/boolean_logical_indexing.tex b/programming/exercises/boolean_logical_indexing.tex
index d91b3d8..315efe7 100644
--- a/programming/exercises/boolean_logical_indexing.tex
+++ b/programming/exercises/boolean_logical_indexing.tex
@@ -62,9 +62,11 @@ following pattern: ``variables\_datatypes\_\{lastname\}.m''
     \part Execute and explain: \verb+bitand(10, 8)+
     \part Execute and explain: \verb+bitor(10, 8)+
   \end{parts}
-\item Implement the following Boolean expressions. Test using randomly selected integer values for \verb+x+ and \verb+y+.
+\item Implement the following Boolean expressions. Test your
+  implementations using random integer
+  numbers for \verb+x+ and \verb+y+ (\verb+randi+).
   \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+ is 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+ and \verb+y+ are not equal zero or \verb+x+ and \verb+y+ are equal.
   \end{parts}
 \end{questions}
@@ -82,7 +84,7 @@ matrices that match in certain criteria. This process is called
   the following commands and explain.
   \begin{parts}
     \part \verb+x < 5+
-    \part \verb+x( x < 5) )+
+    \part \verb+x( (x < 5) )+
     \part \verb+x( (y <= 2) )+
     \part \verb+x( (x > 2) | (y < 8) )+
     \part \verb+x( (x == 0) & (y == 0) )+
@@ -94,6 +96,19 @@ matrices that match in certain criteria. This process is called
     \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).
   \end{parts}
+
+
+  \question Plotting a periodic signal. 
+  \begin{parts}
+    \part Load the file ``signal.mat'' into the workspace (use
+    \verb+load('signal.mat')+ or use the UI for it). It contains two
+    variables \verb+signal+ and \verb+time+. The signal has a period of
+    0.2\,s
+    \part What is the size of the data?
+    \part What is the temporal resolution of the time axis?
+    \part Plot the full data. Make sure that the axes are properly labeled (script chapter 3, or the matlab documentation).
+    \part Use logical indexing to select the periods individually and plot them into the same plot (first period starts at time 0.0\,s, the next at 0.2\,s and so on).
+  \end{parts}
 \end{questions}
 
 \end{document}