Lybniz User Manual

• 1. Using Lybniz
• 2. Accelerator Keys
• 3. Operators and Functions
• 4. About Lybniz

Lybniz is a simple mathematical function graph plotter.

Using Lybniz

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

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
	Define functions
	Zoom in
	Zoom out
	Reset zoom
	Fullscreen
	Menu

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()
og()	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 Lybniz

Lybniz was originally written by Thomas Führinger (ThomasFuhringer@Yahoo.com). It is now maintained by Sam Tygier (samtygier@yahoo.co.uk). Maemo port is made by Daniel Martín Yerga (dyerga@gmail.com). To find more information about Lybniz, please visit the Lybniz Web page.

This program is distributed under the revised BSD license.