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removed \codeterm (replaced by \entermde)

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Jan Benda 2019-12-10 09:14:10 +01:00
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66
codestyle/lecture/codestyle.tex
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@ -33,7 +33,7 @@ by calling functions that work on the data and managing the
results. Applying this structure makes it easy to understand the flow results. Applying this structure makes it easy to understand the flow
of the program but two questions remain: (i) How to organize the files of the program but two questions remain: (i) How to organize the files
on the file system and (ii) how to name them that the controlling on the file system and (ii) how to name them that the controlling
script is easily identified among the other \codeterm[m-file]{m-files}. script is easily identified among the other \entermde[m-file]{m-File}{m-files}.
Upon installation \matlab{} creates a folder called \file{MATLAB} in Upon installation \matlab{} creates a folder called \file{MATLAB} in
the user space (Windows: My files, Linux: Documents, MacOS: the user space (Windows: My files, Linux: Documents, MacOS:
@ -43,7 +43,7 @@ moment. Of course, any other location can specified as well. Generally
it is of great advantage to store related scripts and functions within it is of great advantage to store related scripts and functions within
the same folder on the hard drive. An easy approach is to create a the same folder on the hard drive. An easy approach is to create a
project-specific folder structure that contains sub-folders for each project-specific folder structure that contains sub-folders for each
task (analysis) and to store all related \codeterm[m-file]{m-files} task (analysis) and to store all related \entermde[m-file]{m-File}{m-files}
(screenshot \ref{fileorganizationfig}). In these task-related folders (screenshot \ref{fileorganizationfig}). In these task-related folders
one may consider to create a further sub-folder to store results one may consider to create a further sub-folder to store results
(created figures, result data). On the project level a single script (created figures, result data). On the project level a single script
@ -73,18 +73,18 @@ Box~\ref{matlabpathbox}).
\begin{ibox}[tp]{\label{matlabpathbox}\matlab{} search path} \begin{ibox}[tp]{\label{matlabpathbox}\matlab{} search path}
The \codeterm{search path} defines where \matlab{} looks for scripts The \entermde{Suchpfad}{search path} defines where \matlab{} looks
and functions. When calling a function from the command line for scripts and functions. When calling a function from the command
\matlab{} needs to figure out which function is addressed and starts line \matlab{} needs to figure out which function is addressed and
looking for it in the current path. If this fails it will crawl all starts looking for it in the current path. If this fails it will
locations listed in the search path (see figure). The crawl all locations listed in the search path (see figure). The
\codeterm{search path} is basically a list of folders. \matlab{} \entermde{Suchpfad}{search path} is basically a list of
will go through this list from front to end and the search will stop folders. \matlab{} will go through this list from front to end and
on the first match. This implies that the order in the search path the search will stop on the first match. This implies that the order
may affect which version of functions that share the same name is in the search path may affect which version of functions that share
used. Note: \matlab{} does not perform a recursive search. That is, the same name is used. Note: \matlab{} does not perform a recursive
a function that resides in a sub-folder that is not explicitly search. That is, a function that resides in a sub-folder that is not
listed in the \codeterm{search path} will not be found. explicitly listed in the \entermde{Suchpfad}{search path} will not be found.
\vspace{2ex} \vspace{2ex}
\includegraphics[width=0.9\textwidth]{search_path} \includegraphics[width=0.9\textwidth]{search_path}
@ -307,7 +307,7 @@ and to briefly explain what they do. Whenever one feels tempted to do
this, one could also consider to delegate the respective task to a this, one could also consider to delegate the respective task to a
function. In most cases this is preferable. function. In most cases this is preferable.
Not delegating the tasks leads to very long \codeterm[m-file]{m-files} Not delegating the tasks leads to very long \entermde[m-file]{m-File}{m-files}
which can be confusing. Sometimes such a code is called ``spaghetti which can be confusing. Sometimes such a code is called ``spaghetti
code''. It is high time to think about delegation of tasks to code''. It is high time to think about delegation of tasks to
functions. functions.
@ -323,9 +323,9 @@ functions.
\end{important} \end{important}
\subsection{Local and nested functions} \subsection{Local and nested functions}
Generally, functions live in their own \codeterm[m-file]{m-files} that Generally, functions live in their own \entermde[m-file]{m-File}{m-files} that
have the same name as the function itself. Delegating tasks to have the same name as the function itself. Delegating tasks to
functions thus leads to a large set of \codeterm[m-file]{m-files} functions thus leads to a large set of \entermde[m-file]{m-File}{m-files}
which increases complexity and may lead to confusion. If the delegated which increases complexity and may lead to confusion. If the delegated
functionality is used in multiple instances, it is still advisable to functionality is used in multiple instances, it is still advisable to
do so. On the other hand, when the delegated functionality is only do so. On the other hand, when the delegated functionality is only
@ -335,15 +335,17 @@ used within the context of another function \matlab{} allows to define
within the same file. Listing \ref{localfunctions} shows an example of within the same file. Listing \ref{localfunctions} shows an example of
a local function definition. a local function definition.
\pagebreak[3] \lstinputlisting[label=localfunctions, caption={Example \pagebreak[3]
for local functions.}]{calculateSines.m} \lstinputlisting[label=localfunctions, caption={Example for local
functions.}]{calculateSines.m}
\emph{Local function} live in the same \codeterm{m-file} as the main \emph{Local function} live in the same \entermde{m-File}{m-file} as
function and are only available in this context. Each local function the main function and are only available in this context. Each local
has its own \codeterm{scope}, that is, the local function can not function has its own \enterm{scope}, that is, the local function can
access (read or write) variables of the calling function. Interaction not access (read or write) variables of the calling
with the local function requires to pass all required arguments and to function. Interaction with the local function requires to pass all
take care of the return values of the function. required arguments and to take care of the return values of the
function.
\emph{Nested functions} are different in this respect. They are \emph{Nested functions} are different in this respect. They are
defined within the body of the parent function (between the keywords defined within the body of the parent function (between the keywords
@ -356,13 +358,13 @@ should take care when defining nested functions.
\section{Specifics when using scripts} \section{Specifics when using scripts}
A similar problem as with nested function arises when using scripts A similar problem as with nested function arises when using scripts
(instead of functions). All variables that are defined within a script (instead of functions). All variables that are defined within a script
become available in the global \codeterm{workspace}. There is the risk become available in the global \enterm{workspace}
of name conflicts, that is, a called sub-script redefines or uses the (\determ{Arbeitsbereich}). There is the risk of name conflicts, that
same variable name and may \emph{silently} change its content. The is, a called sub-script redefines or uses the same variable name and
user will not be notified about this change and the calling script may may \emph{silently} change its content. The user will not be notified
expect a completely different content. Bugs that are based on such about this change and the calling script may expect a completely
mistakes are hard to find since the program itself looks perfectly different content. Bugs that are based on such mistakes are hard to
fine. find since the program itself looks perfectly fine.
To avoid such issues one should design scripts in a way that they To avoid such issues one should design scripts in a way that they
perform their tasks independent from other scripts and functions. perform their tasks independent from other scripts and functions.

5
header.tex
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@ -228,11 +228,6 @@
% the german index. % the german index.
\newcommand{\determ}[2][]{``#2''\ifthenelse{\equal{#1}{}}{\protect\sindex[determ]{#2}}{\protect\sindex[determ]{#1}}} \newcommand{\determ}[2][]{``#2''\ifthenelse{\equal{#1}{}}{\protect\sindex[determ]{#2}}{\protect\sindex[determ]{#1}}}
% \codeterm[index entry]{<code>}
% typeset the term in italics and add it (or the optional argument) to
% the english and the german index.
\newcommand{\codeterm}[2][]{\textit{#2}\ifthenelse{\equal{#1}{}}{\protect\sindex[enterm]{#2}\protect\sindex[determ]{#2}}{\protect\sindex[enterm]{#1}\protect\sindex[determ]{#1}}}
\newcommand{\file}[1]{\texttt{#1}} \newcommand{\file}[1]{\texttt{#1}}
% for escaping special characters into the index: % for escaping special characters into the index:

20
plotting/lecture/plotting.tex
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@ -93,15 +93,15 @@ number of datasets.
\subsection{Simple plotting} \subsection{Simple plotting}
Creating a simple line-plot is rather easy. Assuming there exists a Creating a simple line-plot is rather easy. Assuming there exists a
variable \varcode{y} in the \codeterm{workspace} that contains the variable \varcode{y} in the \entermde{Arbeitsbereich}{workspace} that
measurement data it is enough to call \code[plot()]{plot(y)}. At the contains the measurement data it is enough to call
first call of this function a new \codeterm{figure} will be opened and \code[plot()]{plot(y)}. At the first call of this function a new
the data will be plotted with as a line plot. If you repeatedly call \enterm{figure} will be opened and the data will be plotted with as a
this function the current plot will be replaced unless the line plot. If you repeatedly call this function the current plot will
\code[hold]{hold on} command was issued before. If it was, the current be replaced unless the \code[hold]{hold on} command was issued
plot is held and a second line will be added to it. Calling before. If it was, the current plot is held and a second line will be
\code[hold]{hold off} will release the plot and any subsequent added to it. Calling \code[hold]{hold off} will release the plot and
plotting will replace the previous plot. any subsequent plotting will replace the previous plot.
In our previous call to \varcode{plot} we provided just a single In our previous call to \varcode{plot} we provided just a single
variable containing the y-values of the plot. The x-axis will be variable containing the y-values of the plot. The x-axis will be
@ -375,7 +375,7 @@ purpose. For example, we have a number of measurements of a system's
response to a certain stimulus intensity. There is no dependency response to a certain stimulus intensity. There is no dependency
between the data points, drawing them with a line-plot would be between the data points, drawing them with a line-plot would be
nonsensical (figure\,\ref{scatterplotfig}\,A). In contrast to nonsensical (figure\,\ref{scatterplotfig}\,A). In contrast to
\codeterm{}{plot} we need to provide x- and y-coordinates in order to \code{plot()} we need to provide x- and y-coordinates in order to
draw the data. In the example we also provide further arguments to set draw the data. In the example we also provide further arguments to set
the size, color of the dots and specify that they are filled the size, color of the dots and specify that they are filled
(listing\,\ref{scatterlisting1}). (listing\,\ref{scatterlisting1}).

108
programming/lecture/programming.tex
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@ -76,13 +76,15 @@ z =
Line 1 can be read like: ``Create a variable with the name \varcode{x} Line 1 can be read like: ``Create a variable with the name \varcode{x}
and assign the value 38''. The equality sign is the so called and assign the value 38''. The equality sign is the so called
\codeterm[Operator!assignment]{assignment operator}. Line 5 defines a variable \varcode{y} \entermde[Operator!assignment]{Operator!Zuweisungs@Zuweisungs\texttildelow}{assignment
and assigns an empty value. If not explicitly specified \matlab{} operator}. Line 5 defines a variable \varcode{y} and assigns an
variables will have the \codeterm{double} (a numeric data type, see empty value. If not explicitly specified \matlab{} variables will have
below) data type. In line 9, however, we create a variable \varcode{z} the \code{double} (a numeric data type, see below) data type. In
and assign the character ``A'' to it. Accordingly, \varcode{z} does line 9, however, we create a variable \varcode{z} and assign the
not have the numeric \codeterm{double} data type but is of the type character ``A'' to it. Accordingly, \varcode{z} does not have the
\codeterm{character}. \textbf{Note:} \matlab{} uses single quotes for characters or strings of characters. numeric \code{double} data type but is a
\enterm{character} type. \textbf{Note:} \matlab{} uses single quotes for
both characters or strings of characters.
There are two ways to find out the actual data type of a variable: the There are two ways to find out the actual data type of a variable: the
\code{class()} and the \code{whos} functions. While \code{class()} \code{class()} and the \code{whos} functions. While \code{class()}
@ -121,7 +123,7 @@ x y z
\pagebreak[4] \pagebreak[4]
\subsection{Working with variables} \subsection{Working with variables}
We can certainly work, i.e. do calculations, with variables. \matlab{} We can certainly work, i.e. do calculations, with variables. \matlab{}
knows all basic \codeterm[Operator!arithmetic]{arithmetic operators} knows all basic \entermde[Operator!arithmetic]{Operator!arithmetischer}{arithmetic operators}
such as \code[Operator!arithmetic!1add@+]{+}, such as \code[Operator!arithmetic!1add@+]{+},
\code[Operator!arithmetic!2sub@-]{-}, \code[Operator!arithmetic!2sub@-]{-},
\code[Operator!arithmetic!3mul@*]{*} and \code[Operator!arithmetic!3mul@*]{*} and
@ -164,17 +166,17 @@ their values. Whenever the value of a variable should change, the
As mentioned above, the data type associated with a variable defines how the stored bit pattern is interpreted. The major data types are: As mentioned above, the data type associated with a variable defines how the stored bit pattern is interpreted. The major data types are:
\begin{itemize} \begin{itemize}
\item \codeterm{integer}: Integer numbers. There are several subtypes \item \enterm{integer}: Integer numbers. There are several subtypes
which, for most use-cases, can be ignored when working in \matlab{}. which, for most use-cases, can be ignored when working in \matlab{}.
\item \codeterm{single} \codeterm{double}: Floating point numbers. In \item \enterm{single} \enterm{double}: Floating point numbers. In
contrast to the real numbers that are represented with this data contrast to the real numbers that are represented with this data
type the number of numeric values that can be represented is limited type the number of numeric values that can be represented is limited
(countable). (countable).
\item \codeterm{complex}: Complex numbers having a real and imaginary \item \enterm{complex}: Complex numbers having a real and imaginary
part. part.
\item \codeterm{logical}: Boolean values that can be evaluated to \item \enterm{logical}: Boolean values that can be evaluated to
\code{true} or \code{false}. \code{true} or \code{false}.
\item \codeterm{char}: ASCII characters. \item \enterm{character}: ASCII characters.
\end{itemize} \end{itemize}
There is a variety of numeric data types that require different There is a variety of numeric data types that require different
amounts of memory and have different ranges of values that can be amounts of memory and have different ranges of values that can be
@ -196,7 +198,7 @@ represented (table~\ref{dtypestab}).
\end{tabular} \end{tabular}
\end{table} \end{table}
By default \matlab{} uses the \codeterm{double} data type whenever By default \matlab{} uses the \enterm{double} data type whenever
numerical values are stored. Nevertheless, there are use-cases numerical values are stored. Nevertheless, there are use-cases
in which different data types are better suited. Box~\ref{daqbox} in which different data types are better suited. Box~\ref{daqbox}
exemplifies one of such cases. exemplifies one of such cases.
@ -229,7 +231,7 @@ exemplifies one of such cases.
In this context it is most efficient to store the measured values as In this context it is most efficient to store the measured values as
\code{int16} instead of \code{double} numbers. Storing floating \code{int16} instead of \code{double} numbers. Storing floating
point numbers requires four times more memory (8 instead of 2 point numbers requires four times more memory (8 instead of 2
\codeterm{Byte}, 64 instead of 16 bit) and offers no additional bytes, 64 instead of 16 bit) and offers no additional
information. information.
\end{ibox} \end{ibox}
@ -338,8 +340,8 @@ ans =
The content of a vector is accessed using the element's index The content of a vector is accessed using the element's index
(figure~\ref{vectorindexingfig}). Each element has an individual (figure~\ref{vectorindexingfig}). Each element has an individual
\codeterm{index} that ranges (int \matlab{}) from 1 to the number of \entermde{Index}{index} that ranges (int \matlab{}) from 1 to the
elements irrespective of the type of vector. number of elements irrespective of the type of vector.
\begin{figure}[ht] \begin{figure}[ht]
\includegraphics[width=0.4\columnwidth]{arrayIndexing} \includegraphics[width=0.4\columnwidth]{arrayIndexing}
@ -350,7 +352,7 @@ elements irrespective of the type of vector.
\begin{important}[Indexing] \begin{important}[Indexing]
Elements of a vector are accessed via their index. This process is Elements of a vector are accessed via their index. This process is
called \codeterm{indexing}. called \entermde{Indizierung}{indexing}.
In \matlab{} the first element has the index one. In \matlab{} the first element has the index one.
@ -651,7 +653,7 @@ elements of a matrix by it's index. Similar to a coordinate system
each element is addressed using an n-tuple with $n$ the number of each element is addressed using an n-tuple with $n$ the number of
dimensions (figure~\ref{matrixindexingfig}, dimensions (figure~\ref{matrixindexingfig},
listing~\ref{matrixIndexing}). This type of indexing is called listing~\ref{matrixIndexing}). This type of indexing is called
\codeterm{subscript indexing}. The first coordinate refers always to \enterm[indexing!subscript]{subscript indexing}. The first coordinate refers always to
the row, the second to the column, the third to the page, and so on. the row, the second to the column, the third to the page, and so on.
\begin{lstlisting}[caption={Accessing elements in matrices, indexing.}, label=matrixIndexing] \begin{lstlisting}[caption={Accessing elements in matrices, indexing.}, label=matrixIndexing]
@ -835,9 +837,9 @@ values (\varcode{true} or \varcode{false}). This implies that we need
only a single bit to store this information as 0 (false) or 1 (true) only a single bit to store this information as 0 (false) or 1 (true)
It would be a waste of space to use more than one bit for It would be a waste of space to use more than one bit for
it. Accordingly, \matlab{} knows a special data type it. Accordingly, \matlab{} knows a special data type
(\codeterm{logical}) to store such information efficiently. \matlab{} (\enterm{logical}) to store such information efficiently. \matlab{}
also knows the keywords \code{true} and \code{false} which are also knows the keywords \code{true} and \code{false} which are
synonymous for the \codeterm{logical} values 1 and synonymous for the logical values 1 and
0. Listing~\ref{logicaldatatype} exemplifies the use of the logical 0. Listing~\ref{logicaldatatype} exemplifies the use of the logical
data type. data type.
@ -884,10 +886,11 @@ table~\ref{logicaloperators}) which are introduced in the following
sections. sections.
\subsection{Relational operators} \subsection{Relational operators}
With \codeterm[Operator!relational]{relational operators} With
(table~\ref{relationaloperators}) we can ask questions such as: ''Is \entermde[Operator!relational]{Operator!Vergleichs@Vergleichs\texttildelow}{relational
the value of variable \varcode{a} larger than the value of operators} (table~\ref{relationaloperators}) we can ask questions
\varcode{b}?'' or ``Is the value in \varcode{a} equal to the one such as: ''Is the value of variable \varcode{a} larger than the value
of \varcode{b}?'' or ``Is the value in \varcode{a} equal to the one
stored in variable \varcode{b}?''. stored in variable \varcode{b}?''.
\begin{table}[h!] \begin{table}[h!]
@ -943,7 +946,7 @@ number is greater than a certain threshold (\varcode{x > 0.25}). But what
if we wanted to check whether the number falls into the range greater if we wanted to check whether the number falls into the range greater
than 0.25 but less than 0.75? Numbers that fall into this range must than 0.25 but less than 0.75? Numbers that fall into this range must
satisfy the one and the other condition. With satisfy the one and the other condition. With
\codeterm[Operator!logical]{logical \entermde[Operator!logical]{Operator!logischer}{logical
operators} (table~\ref{logicaloperators}) single Boolean expressions operators} (table~\ref{logicaloperators}) single Boolean expressions
can be joined to form more complex Boolean operations. can be joined to form more complex Boolean operations.
@ -1071,7 +1074,7 @@ values stored in a vector or matrix. It is very powerful and, once
understood, very intuitive. understood, very intuitive.
The basic concept is that applying a Boolean operation on a vector The basic concept is that applying a Boolean operation on a vector
results in a \codeterm{logical} vector of the same size (see results in a \enterm{logical} vector of the same size (see
listing~\ref{logicaldatatype}). This logical vector is then used to listing~\ref{logicaldatatype}). This logical vector is then used to
select only those values for which the logical vector is true. Line 14 select only those values for which the logical vector is true. Line 14
in listing~\ref{logicalindexing1} can be read: ``Select all those in listing~\ref{logicalindexing1} can be read: ``Select all those
@ -1152,14 +1155,14 @@ segment of data of a certain time span (the stimulus was on,
this if downward compatibility is desired/needed.} this if downward compatibility is desired/needed.}
\textbf{Structures} Arrays of named fields that each can contain \textbf{Structures} Arrays of named fields that each can contain
arbitrary data types. \codeterm{Structures} can have sub-structures arbitrary data types. \enterm{Structures} can have sub-structures
and thus can build a trees. Structures are often used to combine and thus can build a trees. Structures are often used to combine
data and metadata in a single variable. data and metadata in a single variable.
\textbf{Cell arrays} Arrays of variables that contain different \textbf{Cell arrays} Arrays of variables that contain different
types. Unlike structures, the entries of a \codeterm{cell array} are types. Unlike structures, the entries of a \enterm{cell array} are
not named. Indexing in \codeterm[cell array]{cell arrays} requires a not named. Indexing in \enterm[cell array]{cell arrays} requires a
special operator the \code{\{\}}. \matlab{} uses \codeterm[cell special operator the \code{\{\}}. \matlab{} uses \enterm[cell
array]{cell arrays} for example when strings of different lengths array]{cell arrays} for example when strings of different lengths
should be stored in the same variable: \varcode{months = \{'Januar', should be stored in the same variable: \varcode{months = \{'Januar',
'February', 'March', 'April', 'May', 'Jun'\};}. Note the curly 'February', 'March', 'April', 'May', 'Jun'\};}. Note the curly
@ -1167,14 +1170,14 @@ segment of data of a certain time span (the stimulus was on,
indexing. indexing.
\textbf{Tables} Tabular structure that allows to have columns of \textbf{Tables} Tabular structure that allows to have columns of
varying type combined with a header (much like a spreadsheet). different types combined with a header (much like a spreadsheet).
\textbf{Timetables} Array of values that are associated with a \textbf{Timetables} Array of values that are associated with a
timestamp. For example one can store measurements, that are made in timestamp. For example one can store measurements, that are made in
irregular intervals togehter with the measurement time in a single irregular intervals togehter with the measurement time in a single
variable. Without the \codeterm{Timetable} data type at least two variable. Without the \enterm{Timetable} data type at least two
variables (one storing the time, the other the measurement) would be variables (one storing the time, the other the measurement) would be
required. \codeterm[Timetable]{Timetables} offer specific required. \enterm[Timetable]{Timetables} offer specific
convenience functions to work with timestamps. convenience functions to work with timestamps.
\textbf{Maps} In a \code{containers.Map} a \entermde{Wert}{value} is \textbf{Maps} In a \code{containers.Map} a \entermde{Wert}{value} is
@ -1185,8 +1188,8 @@ segment of data of a certain time span (the stimulus was on,
\textbf{Categorical arrays} are used to stored values that come from \textbf{Categorical arrays} are used to stored values that come from
a limited set of values, e.g. Months. Such categories can then be a limited set of values, e.g. Months. Such categories can then be
used for filter operations. \codeterm{Categorical arrays} are often used for filter operations. \enterm{Categorical arrays} are often
used in conjunctions with \codeterm{Tables}. used in conjunctions with \enterm{Tables}.
\begin{lstlisting}[caption={Using Categorical arrays}, label=categoricallisting] \begin{lstlisting}[caption={Using Categorical arrays}, label=categoricallisting]
>> months = categorical({'Jan', 'Feb', 'Jan', 'Dec'}); >> months = categorical({'Jan', 'Feb', 'Jan', 'Dec'});
>> events = [10, 2, 18, 20 ]; >> events = [10, 2, 18, 20 ];
@ -1495,22 +1498,22 @@ and executed line-by-line from top to bottom.
\item \entermde[Object]{Objekte}{Objects} (not covered here) \item \entermde[Object]{Objekte}{Objects} (not covered here)
\end{enumerate} \end{enumerate}
Programs are stored in so called \codeterm[m-file]{m-files} Programs are stored in so called \entermde[m-file]{m-File}{m-files}
(e.g. \file{myProgram.m}). To use them they have to be \emph{called} (e.g. \file{myProgram.m}). To use them they have to be \emph{called}
from the command line or from within another program. Storing your code in from the command line or from within another program. Storing your
programs increases the re-usability. So far we have used code in programs increases the re-usability. So far we have used
\emph{scripts} to store the solutions of the exercises. Any variable \emph{scripts} to store the solutions of the exercises. Any variable
that was created appeared in the \codeterm{workspace} and existed even that was created appeared in the \entermde{Arbeitsbereich}{workspace}
after the program was finished. This is very convenient but also bears and existed even after the program was finished. This is very
some risks. Consider the case that \file{script\_a.m} creates a convenient but also bears some risks. Consider the case that
certain variable and assigns a value to it for later use. Now it calls \file{script\_a.m} creates a certain variable and assigns a value to
a second program (\file{script\_b.m}) that, by accident, uses the same it for later use. Now it calls a second program (\file{script\_b.m})
variable name and assigns a different value to it. When that, by accident, uses the same variable name and assigns a different
\file{script\_b.m} is done, the control returns to \file{script\_a.m} value to it. When \file{script\_b.m} is done, the control returns to
and if it now wants to read the previously stored variable, it will \file{script\_a.m} and if it now wants to read the previously stored
contain a different value than expected. Bugs like this are hard to variable, it will contain a different value than expected. Bugs like
find since each of the programs alone is perfectly fine and works as this are hard to find since each of the programs alone is perfectly
intended. A solution for this problem are the fine and works as intended. A solution for this problem are the
\entermde[function]{Funktion}{functions}. \entermde[function]{Funktion}{functions}.
\subsection{Functions} \subsection{Functions}
@ -1533,8 +1536,9 @@ argument(s). The function head is then followed by the function's
body. A function is ended by and \code{end} (this is in fact optional body. A function is ended by and \code{end} (this is in fact optional
but we will stick to this). Each function that should be directly used but we will stick to this). Each function that should be directly used
by the user (or called from other programs) should reside in an by the user (or called from other programs) should reside in an
individual \codeterm{m-file} that has the same name as the function. By individual \entermde{m-File}{m-file} that has the same name as the
using functions instead of scripts we gain several advantages: function. By using functions instead of scripts we gain several
advantages:
\begin{itemize} \begin{itemize}
\item Encapsulation of program code that solves a certain task. It can \item Encapsulation of program code that solves a certain task. It can
be easily re-used in other programs. be easily re-used in other programs.