Lybniz User Manual


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 the Scale Style menu.

To save the graph in PNG format choose Save graph from the menu.
Using the Evaluate tool button you get a dialog box that allows input of an x value and calculates y values.


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 following math functions available.

Function Description
acos(x) Returns the arc cosine of x, in radians.
asin(x) Returns the arc sine of x, in radians
atan(x) Returns the arc tangent of x, in radians
atan2(y, x) Returns atan(y / x), in radians
ceil(x) Returns the ceiling of x as a float, the smallest integer value greater than or equal to x
cos(x) Returns the cosine of x radians
cosh(x) Returns the hyperbolic cosine of x
degrees(x) Converts angle x from radians to degrees
exp(x) Returns e**x.
fabs(x) Returns the absolute value of x
fac(x) Returns the factorial of x (or x!). Note: only works with positive integers
floor(x) Returns the floor of x as a float, the largest integer value less than or equal to x
hypot(x, y) Returns the Euclidean norm, sqrt(x*x + y*y). This is the length of the vector from the origin to point (x, y)
ldexp(x, i) Returns x * (2**i)
log(x) Returns the base-10 logarithm of x.
ln(x) Returns the natural logarithm of x
modf(x) Returns the fractional and integer parts of x. Both results carry the sign of x and are floats
pow(x, y) Returns x raised to the power y
radians(x) Converts angle x from degrees to radians
sin(x) Returns the sine of x radians
sinc(x) Returns sin(x)/x
sinh(x) Returns the hyperbolic sine of x
sqrt(x) Returns the square root of x.
tan(x) Returns the tangent of x radians
tanh(x) Returns the hyperbolic tangent of 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.