# Command Reference

## The main &kmplot; window

Here's a screenshot of the &kmplot; main window
Here's a screenshot of the &kmplot; main window

## The Functions Menu

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 explicit and parametric form. With specific extensions it is possible to add first and second derivation and to choose values for the function group parameter.

### Syntax

Some syntax rules must be complied with:

    name(var1[, var2])=term [;extensions]

name

  The functions name. If the first character is r the parser assumes that you use polar coordinates. If the first character is x (for instance xfunc) the parser expects a second function with a leading y (here yfunc) to define the function in parametric form.

var1

  The functions variable

var2

  The function group parameter. It must be seperated by a comma.

term

  The function's term

### Predefined Function Names and Constants

Names
Predefined function names and constants are shown in this window.

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

### Extensions

N

  The function will be stored but not be drawn. So it can be used like any other user defined or predefined function.

A1

  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.

A2

  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.

D[a,b]

  ...

P[a{,b}]

  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.

## Coordinate Systems

### Plotting Area

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.

Parametric functions are plotted for parameter values from 0 upto 2&pgr;. This range can be set in the functions dialog window manually, too.

### Cross Hair Cursor

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.

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.

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.

### Types of Coordinate Systems

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.