# &app; User Manual

&app; is a simple mathematical function graph plotter.

## Using &app;

Enter functions in Python syntax with `x` as the dependent variable. Press the Plot button to see the graph.

### &app; Window

Shows &app; main window displaying 3 graphs.

Constants and functions of the `math` module are available.

Examples:

    x**3 - 2 * x
    2 * cos(x)
    e ** (x / -5) * sin(x)

xMin, xMax, yMin, yMax define the boundaries of the range on the abszissa and ordinate to be displayed.

To zoom in, activate the Zoom In tool button. It divides the range boundaries by half. Zoom out does the opposite. To closer inspect a specific section, drag the mouse cursor over an area. After release of the button the area thus marked will be displayed.

The scale automatically adjusts as you zoom in and out. To switch between decimal and radian styles, use Graph Scale Style Decimal or Graph Scale Style Radians

.

If you wish to use a custom scale select Graph Scale Style Custom. You can then use the xScale, yScale entries to input the intervals at which marks are displayed on the respective axis. They can also be stated as expressions. Examples:

    xMin = pi * -2
    xMax = pi * 2
    xScale = pi / 2

To save the graph in PNG format choose File Save.

Using Graph Evaluate you get a dialog box that allows input of an `x` value and calculates `y` values.

## Accelerator Keys

Accelerator | Function
Ctrl L | Plot graph
Ctrl+ | Zoom in
Ctrl- | Zoom out
Ctrl R | Reset zoom
Ctrl S | Save graph
Ctrl E | Evaluate functions
Ctrl Q | Quit &app;

## Operators and Functions

Expressions are entered in python syntax. The following operators can be used. Note: multiplication is not implied (use "2*x" not "2x")

Operator | Description
+,-,*,/ | Plus, minus, multiply, divide
// | Integer divide. (eg 3/2 = 1)
**, ^ | Raise to the power of
% | Remainder

Lybniz has all the math functions of the python standard library available.

acos() asin() atan() atan2() ceil() cos() cosh() degrees() exp() fabs() floor() fmod() frexp() | hypot() ldexp() log() log10() modf() pow() radians() sin() sinh() sqrt() tan() tanh()

These are documented at Python Library Reference - Math.

There are also a few extra functions that may be useful.

Function | Description
fac(x) | Factorial of x (or x!). Note: only works with positive integers.
sinc(x) | sin(x)/x.

The constants pi and e can be used.

## About &app;

&app; was originally written by Thomas Führinger (ThomasFuhringer@Yahoo.com). It is now maintained by Sam Tygier (samtygier@yahoo.co.uk). To find more information about &app;, please visit the &app; Web page.

This program is distributed under the revised BSD license.