teaching/scientificComputing
Archived
3
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

fixed many index entries

Browse Source
This commit is contained in:
Jan Benda
2019-12-09 20:01:27 +01:00
parent f24c14e6f5
commit bf52536b7b
12 changed files with 332 additions and 306 deletions
Download Patch File Download Diff File Expand all files Collapse all files

77
plotting/lecture/plotting.tex
View File

@@ -112,16 +112,15 @@ the missing information ourselves. Thus, we need a second variable
that contains the respective \varcode{x} values. The length of
\varcode{x} and \varcode{y} must be the same otherwise the later call
of the \varcode{plot} function will raise an error. The respective
call will expand to \code[plot()]{plot(x, y)}. The x-axis will be now
be scaled from the minimum in \varcode{x} to the maximum of
\varcode{x} and by default it will be plotted as a line plot with a
solid blue line of the linewidth 1pt. A second plot that is added to the
figure will be plotted in red using the same settings. The
order of the used colors depends on the \enterm{colormap} settings
which can be adjusted to personal taste or
need. Table\,\ref{plotlinestyles} shows some predefined values that
can be chosen for the line style, the marker, or the color. For
additional options consult the help.
call will expand to \code[plot()]{plot(x, y)}. The x-axis will now be
scaled from the minimum in \varcode{x} to the maximum of \varcode{x}
and by default it will be plotted as a line plot with a solid blue
line of the linewidth 1pt. A second plot that is added to the figure
will be plotted in red using the same settings. The order of the used
colors depends on the \enterm{colormap} settings which can be adjusted
to personal taste or need. Table\,\ref{plotlinestyles} shows some
predefined values that can be chosen for the line style, the marker,
or the color. For additional options consult the help.
\begin{table}[htp]
\titlecaption{Predefined line styles (left), colors (center) and
@@ -184,8 +183,8 @@ chosen.
\subsection{Changing the axes properties}
The first thing a plot needs are axis labels with correct units. By
calling the functions \code[xlabel]{xlabel('Time [ms]')} and
\code[ylabel]{ylabel('Voltage [mV]')} these can be set. By default the
calling the functions \code[xlabel()]{xlabel('Time [ms]')} and
\code[ylabel()]{ylabel('Voltage [mV]')} these can be set. By default the
axes will be scaled to show the full extent of the data. The extremes
will be selected as the closest integer for small values or the next
full multiple of tens, hundreds, thousands, etc.\ depending on the
@@ -196,8 +195,8 @@ functions expect a single argument, that is a 2-element vector
containing the minimum and maximum value. Table\,\ref{plotaxisprops}
lists some of the commonly adjusted properties of an axis. To set
these properties, we need to have the axes object which can either be
stored in a variable when calling \varcode{plot} (\code{axes =
plot(x,y);}) or can be retrieved using the \code[gca]{gca} function
stored in a variable when calling \varcode{plot} (\varcode{axes =
plot(x,y);}) or can be retrieved using the \code{gca()} function
(gca stands for ``get current axes''). Changing the properties of the axes
object will update the plot (listing\,\ref{niceplotlisting}).
@@ -253,8 +252,8 @@ and the placement of the axes on the
paper. Table\,\ref{plotfigureprops} lists commonly used
properties. For a complete reference check the help. To change the
figure's appearance, we need to change the properties of the figure
object which can be retrieved during creation of the figure (\code{fig
= figure();}) or by using the \code{gcf} (``get current figure'')
object which can be retrieved during creation of the figure (\code[figure()]{fig
= figure();}) or by using the \code{gcf()} (``get current figure'')
command.
The script shown in the listing\,\ref{niceplotlisting} exemplifies
@@ -334,10 +333,10 @@ the last one defines the output format (box\,\ref{graphicsformatbox}).
properties could be read and set using the functions
\code[get()]{get} and \code[set()]{set}. The first argument these
functions expect are valid figure or axis \emph{handles} which were
returned by the \code{figure} and \code{plot} functions, or could be
retrieved using \code[gcf()]{gcf} or \code[gca()]{gca} for the
returned by the \code{figure()} and \code{plot()} functions, or could be
retrieved using \code{gcf()} or \code{gca()} for the
current figure or axis handle, respectively. Subsequent arguments
passed to \code{set} are pairs of a property's name and the desired
passed to \code{set()} are pairs of a property's name and the desired
value.
\begin{lstlisting}[caption={Using set to change figure and axis properties.}]
frequency = 5; % frequency of the sine wave in Hz
@@ -351,8 +350,8 @@ the last one defines the output format (box\,\ref{graphicsformatbox}).
set(figure_handle, 'PaperSize', [5.5, 5.5], 'PaperUnit', 'centimeters', ...
'PaperPosition', [0, 0, 5.5, 5.5]);
\end{lstlisting}
With newer versions the handles returned by \varcode{gcf} and
\varcode{gca} are ``objects'' and setting properties became much
With newer versions the handles returned by \code{gcf()} and
\code{gca()} are ``objects'' and setting properties became much
easier as it is used throughout this chapter. For downward
compatibility with older versions set and get still work in current
versions of \matlab{}.
@@ -371,7 +370,7 @@ For some types of plots we present examples in the following sections.
\subsection{Scatter}
For displaying events or pairs of x-y coordinates the standard line
plot is not optimal. Rather, we use \code[scatter()]{scatter} for this
plot is not optimal. Rather, we use \code{scatter()} for this
purpose. For example, we have a number of measurements of a system's
response to a certain stimulus intensity. There is no dependency
between the data points, drawing them with a line-plot would be
@@ -417,8 +416,8 @@ A very common scenario is to combine several plots in the same
figure. To do this we create so-called subplots
figures\,\ref{regularsubplotsfig},\,\ref{irregularsubplotsfig}. The
\code[subplot()]{subplot()} command allows to place multiple axes onto
a single sheet of paper. Generally, \varcode{subplot} expects three argument
defining the number of rows, column, and the currently active
a single sheet of paper. Generally, \code{subplot()} expects three
argument defining the number of rows, column, and the currently active
plot. The currently active plot number starts with 1 and goes up to
$rows \cdot columns$ (numbers in the subplots in
figures\,\ref{regularsubplotsfig}, \ref{irregularsubplotsfig}).
@@ -439,7 +438,7 @@ figures\,\ref{regularsubplotsfig}, \ref{irregularsubplotsfig}).
By default, all subplots have the same size, if something else is
desired, e.g.\ one subplot should span a whole row, while two others
are smaller and should be placed side by side in the same row, the
third argument of \varcode{subplot} can be a vector or numbers that
third argument of \code{subplot()} can be a vector or numbers that
should be joined. These have, of course, to be adjacent numbers
(\figref{irregularsubplotsfig},
listing\,\ref{irregularsubplotslisting}).
@@ -457,7 +456,7 @@ columns, need to be used in a plot. If you want to create something
more elaborate, or have more spacing between the subplots one can
create a grid with larger numbers of columns and rows, and specify the
used cells of the grid by passing a vector as the third argument to
\varcode{subplot}.
\code{subplot()}.
\lstinputlisting[caption={Script for creating subplots of different
sizes \figref{irregularsubplotsfig}.},
@@ -498,12 +497,12 @@ more apt. Accordingly, four arguments are needed (line 12 in listing
\ref{errorbarlisting}). The first two arguments are the same, the next
to represent the positive and negative deflections.
By default the \code{errorbar} function does not draw a marker. In the
By default the \code{errorbar()} function does not draw a marker. In the
examples shown here we provide extra arguments to define that a circle
is used for that purpose. The line connecting the average values can
be removed by passing additional arguments. The properties of the
errorbars themselves (linestyle, linewidth, capsize, etc.) can be
changed by taking the return argument of \code{errorbar} and changing
changed by taking the return argument of \code{errorbar()} and changing
its properties. See the \matlab{} help for more information.
\begin{figure}[ht]
@@ -530,18 +529,18 @@ areas instead of errorbars: In case you have a lot of data points with
respective errorbars such that they would merge in the figure it is
cleaner and probably easier to read and handle if one uses an error
area instead. To achieve an illustration as shown in
figure\,\ref{errorbarplot} C, we use the \code{fill} command in
figure\,\ref{errorbarplot} C, we use the \code{fill()} command in
combination with a standard line plot. The original purpose of
\code{fill} is to draw a filled polygon. We hence have to provide it
\code{fill()} is to draw a filled polygon. We hence have to provide it
with the vertex points of the polygon. For each x-value we now have
two y-values (average minus error and average plus error). Further, we
want the vertices to be connected in a defined order. One can achieve
this by going back and forth on the x-axis; we append a reversed
version of the x-values to the original x-values using \code{cat} and
\code{fliplr} for concatenation and inversion, respectively (line 3 in
version of the x-values to the original x-values using \code{cat()} and
\code{fliplr()} for concatenation and inversion, respectively (line 3 in
listing \ref{errorbarlisting2}; Depending on the layout of your data
you may need concatenate along a different dimension of the data and
use \code{flipud} instead). The y-coordinates of the polygon vertices
use \code{flipud()} instead). The y-coordinates of the polygon vertices
are concatenated in a similar way (line 4). In the example shown here
we accept the polygon object that is returned by fill (variable p) and
use it to change a few properties of the polygon. The \emph{FaceAlpha}
@@ -561,9 +560,9 @@ connecting the average values (line 12).
The \code[text()]{text()} or \code[annotation()]{annotation()} are
used for highlighting certain parts of a plot or simply adding an
annotation that does not fit or does not belong into the legend.
While \varcode{text} simply prints out the given text string at the
While \code{text()} simply prints out the given text string at the
defined position (for example line in
listing\,\ref{regularsubplotlisting}) the \varcode{annotation}
listing\,\ref{regularsubplotlisting}) the \code{annotation()}
function allows to add some more advanced highlights like arrows,
lines, ellipses, or rectangles. Figure\,\ref{annotationsplot} shows
some examples, the respective code can be found in
@@ -583,9 +582,9 @@ listing\,\ref{annotationsplotlisting}. For more options consult the
\begin{important}[Positions in data or figure coordinates.]
A very confusing pitfall are the different coordinate systems used
by \varcode{text} and \varcode{annotation}. While \varcode{text}
by \varcode{text()} and \varcode{annotation()}. While \varcode{text()}
expects the positions to be in data coordinates, i.e.\,in the limits
of the x- and y-axis, \varcode{annotation} requires the positions to
of the x- and y-axis, \varcode{annotation()} requires the positions to
be given in normalized figure coordinates. Normalized means that the
width and height of the figure are expressed by numbers in the range
0 to 1. The bottom/left corner then has the coordinates $(0,0)$ and
@@ -624,9 +623,9 @@ Lissajous figure. The basic steps are:
is created and opened for writing. This also implies that is has to
be closed after the whole process (line 31).
\item For each frame of the video, we plot the appropriate data (we
use \code[scatter]{scatter} for this purpose, line 20) and ``grab''
use \code{scatter()} for this purpose, line 20) and ``grab''
the frame (line 28). Grabbing is similar to making a screenshot of
the figure. The \code{drawnow}{drawnow} command (line 27) is used to
the figure. The \code{drawnow()} command (line 27) is used to
stop the excution of the for loop until the drawing process is
finished.
\item Write the frame to file (line 29).