<chapter id="commands">
<title>Command Reference</title> 

<sect1 id="kmplot-mainwindow">
<title>The main &kmplot; window</title>

<screenshot>
<screeninfo>Here's a screenshot of the &kmplot; main window</screeninfo>
<mediaobject>
<imageobject>
<imagedata fileref="main.png" format="PNG"/>
</imageobject>
<textobject>
<phrase>Here's a screenshot of the &kmplot; main window</phrase>
</textobject>
</mediaobject>
</screenshot>
</sect1>

<sect1 id="functions">
<title>The <guimenu>Functions</guimenu> Menu</title>

<mediaobject>
<imageobject>
<imagedata fileref="kfkt.png" format="PNG"/>
</imageobject>
</mediaobject>

<para>This menu entry or tool button opens the Functions Editor.  Here
you can enter the functions' equations of up to 10 functions or
function groups.  The parser knows <firstterm>explicit</firstterm> and
<firstterm>parametric</firstterm> form.  With specific extensions it
is possible to add first and second derivation and to choose values
for the function group parameter.</para>

<sect2 id="func-syntax"><title>Syntax</title>

<para>Some syntax rules must be complied with:</para>

<screen>
<userinput>name(var1[, var2])=term [;extensions]</userinput>
</screen>


<variablelist>
<varlistentry>
<term>name</term>
<listitem>

<para>The functions name.  If the first character is <quote>r</quote>
the parser assumes that you use polar coordinates.  If the first
character is <quote>x</quote> (for instance <quote>xfunc</quote>) the
parser expects a second function with a leading <quote>y</quote> (here
<quote>yfunc</quote>) to define the function in parametric form.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>var1</term>
<listitem><para>The functions variable</para></listitem>
</varlistentry>
<varlistentry>
<term>var2</term>
<listitem><para>
The function group parameter. It must be seperated by a comma.
</para></listitem>
</varlistentry>
<varlistentry>
<term>term</term>
<listitem><para>The function's term</para></listitem>
</varlistentry>
</variablelist>
</sect2>

<sect2 id="func-predefined"><title>Predefined Function Names and Constants</title>
<screenshot>
<screeninfo>Names</screeninfo>
<mediaobject>
<imageobject>
<imagedata fileref="namesdlg.png" format="PNG"/>
</imageobject>
<textobject>
<phrase>
Predefined function names and constants are shown in this window.
</phrase>
</textobject>
</mediaobject>
</screenshot>

<para>
These functions and constants and even all user defined functions can
be used to determine the axes settings as well.
</para>

</sect2>

 <!-- 		<sect2 id="func-dialog"><title>Functions Dialog Window</title>
			 <para>...</para>
		 </sect2> -->


<sect2 id="func-extension"><title>Extensions</title>
<variablelist>
<varlistentry>
<term>N</term>
<listitem>
<para>
The function will be stored but not be drawn. 
So it can be used like any other user defined or predefined function.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>A1</term>
<listitem>
<para>
The graph of the derivative of the function will be drawn
additionally with the same color but less line width.
This extension has no effect on functions defined in
parametric form.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>A2</term>
<listitem>
<para>
The graph of the second derivative of the function will be
drawn additionally with the same color but less line width.
This extension has no effect on functions defined in
parametric form.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>D[a,b]</term>
<listitem>
<para>
...
</para>
</listitem>
</varlistentry>
<varlistentry>
<term>P[a{,b}]</term>
<listitem>
<para>
With this extension you can give a list of values for the
parameter of a function group of which the graph should be drawn.
Also terms are allowed.
The use of this extension presumes that the parameter is given as a
second function variable.
</para>
</listitem>
</varlistentry>
</variablelist>
</sect2>
</sect1>

<sect1 id="coord-system"><title>Coordinate Systems</title>

<para><inlinemediaobject>
<imageobject>
<imagedata fileref="ksys1.png" format="PNG"/>
</imageobject>
</inlinemediaobject></para>

<para>
<inlinemediaobject>
<imageobject>
<imagedata fileref="ksys2.png" format="PNG"/>
</imageobject>
</inlinemediaobject></para>

<para>
<inlinemediaobject>
<imageobject>
<imagedata fileref="ksys3.png" format="PNG"/>
</imageobject>
</inlinemediaobject></para>

<sect2 id="coord-area"><title>Plotting Area</title>
<para>
By default explicitly given functions are plotted for visible part of the x-axis. 
For every pixel on the x-axis &kmplot; calculates a function value. 
If the plotting area contains the resulting point it is connected to the last 
drawn point by a line. In the functions dialog window the interval, in which the
graph shall be plotted, can be changed manually.
</para>
<para>
Parametric functions are plotted for parameter values from 0 upto 2&pgr;. 
This range can be set in the functions dialog window manually, too.
</para>
</sect2>
<sect2 id="coord-cross"><title>Cross Hair Cursor</title>
<para>
During the mouse cursor points to the plotting area the cursor changes to a 
cross hair. The current coordinates can be found at the intersections with the 
coordinate axes and also in the status bar at the bottom edge of the main window.
</para>
<para>
You can trace the functions values more precisely by clicking onto or next to a 
graph. The cross hair then will be catched and be colored in the same color as the 
graph. A second click anywhere in the window will leave this trace mode.
</para>
<para>
Please notice that tracing is only possible with explicitly given functions.
The coordinates are allways displayed according to cartesian system of coordinates.
Neither parametric functions, nor functions given in polar coordinates, 
nor derivatives can not be traced this way.
</para>
</sect2>
<sect2 id="coord-types"><title>Types of Coordinate Systems</title>
<para>
As you can define the functions with cartesian or polar coordinates 
the grid can be displayed cartesian or polar divisions. 
Please choose the style for the cartesian grid between lines and little crosses in
the grid dialog window.
</para>
</sect2>
</sect1>

<!-- 
<sect1 id="scale-print"><title>Scaling and Printing</title>
<para>...</para>
</sect1> -->
</chapter>