\label{Authoring_Dynamic_Plot_Tics}

The \textbf{xtics} and \textbf{ytics} tags can be inserted by selecting 
the \textbf{Plot tics} item from the insert selection list of the 
\textbf{gnuplot} tag.

The \textbf{xtics} and \textbf{ytics} tags have identical structure and the
description presented here applies to both.

The tics tags allow specification of the following attributes:

\begin{itemize}

\item \texttt{Location of major tic marks}
``Border'' or ``Axis''.
Tic marks can be placed on the border or on the axes.  The images below
illustrate the effects of each of these options.

\includegraphics[  width=0.40\paperwidth]{Authoring_Dynamic_Plot_Axis_Tics_border}
\includegraphics[  width=0.40\paperwidth]{Authoring_Dynamic_Plot_Axis_Tics_x_axis}

\item \texttt{Mirror tics on opposite axis?}
``Yes'' or ``No''.
If the \textbf{location of tic marks} is set to ``border'' this parameter 
determines if they are shown on both the top and bottom or right and left 
sides of the graph.  The ``mirror'' tic marks are unlabelled.

\includegraphics[  width=0.40\paperwidth]{Authoring_Dynamic_Plot_Axis_Tics_border}
\includegraphics[  width=0.40\paperwidth]{Authoring_Dynamic_Plot_Axis_Tics_nomirror}

\item \texttt{Start major tics at}

The point in graph coordinates which to start making major tics.  
This may be less than or greater than the lower limit for the axis.

\item \texttt{Place a major tic every}

The span, in graph coordinates, between each major tic mark.

\item \texttt{Stop major tics at}

This may be less than or greater than the upper limit for the axis.

\item \texttt{Number of minor tics between major tic marks}

The number of subdivisions to make of the span between major tic marks.
Using a value of ``10'' leads to 9 minor tic marks.  The example below
uses a value of ``5'' to produce 4 tic marks.

\includegraphics[  width=0.40\paperwidth]{Authoring_Dynamic_Plot_Axis_Tics_minor}


\item \texttt{rotate}

For output devices that support it, the \texttt{rotate=`1'} attribute rotates
the tic label.  This is most useful with large lables defined by the
\textbf{tic} tag described below.

\end{itemize}

In addition to specifying regular tic intervals via the attributes of the
\textbf{xtics} and \textbf{ytics} you can specify arbitrary tic locations
by enclosing \textbf{tic} tags within the body of these tags.  Each
\textbf{tic} tag requires the \textbf{location} attribute which specifies the
location of a tic on the axis.  The body of the tag contains the label of
that tic.

The \textbf{xtic} or \textbf{ytic}  \texttt{rotate} attribute can rotate
the label text if the output device supports text rotation.
If \textbf{tic} tags are embedded within the \textbf{xtic} or \textbf{ytic}
tags attributes of those tags that specify tic boundaries and interval are
ignored.  Here's an example of an X axis tic specification in months of the year:

\begin{verbatim}
...
<xtics rotate='on'>
   <tic location='1'>January</tic>
   <tic location='2'>February</tic>
   <tic location='3'>March</tic>
   <tic location='4'>April</tic>
   <tic location='5'>May</tic>
   <tic location='6'>June</tic>
   <tic location='7'>July</tic>
   <tic location='8'>August</tic>
   <tic location='9'>September</tic>
   <tic location='10'>October</tic>
   <tic location='11'>November</tic>
   <tic location='12'>December</tic>
</xtics>
<ytics end="6.0" location="border" start="-6.0" 
       increment="1.0" mirror="on" />
\end{verbatim}

Note that tic locations are completely under your control and do not even have
to be at regular interevals on the axis if that better suits your needs.