 # GDF Plotter - Mathematical grapher

### What is GDF

GDF is a freeware program that allows you to draw any single variable mathematical function, circumferences, ellipses, parabolas, hyperbolas and sheaves of functions on a Cartesian coordinate system.

### Details

• Graph functions, circumferences, ellipses, parabolas, hyperbolas and function families.

• Automatic scan relative maximum and minimum on a graph providing 15 digit precision float values.

• Allows you to refer a function from other function formula and setting input values,. i.g. a(x)=x+1, b(x)=a(x)+1 ; c(x)=a(3)+1. Note: Cannot nest function, i.g. d(x)=a(b(x)) is not valid.
• Show a tendency icon (increasing/decreasing) when traversing graphics.

## How to use GDF

The Graph Manager window shows a list of graphics to be represented on the same Cartesian system of coordinates by clicking the 'Graph' button. It allows you to easily add, edit, or remove selected graphics. It also provides a way to adjust the range (initial and final value for x and y), quality (the more values are calculated to define a graphic, the more well shaped it would look, however while graphing sheaves one may be interested in speed up the drawing), and ruler (define how many real numbers represent a mark on each axis). Defining or editing a graphic is easy by means of the Edition Object window as shown below. You just click type of graph you want to create or edit and fill the form specifying value such as the coordinate for the focus, center, etc. It assumes you're familiarized with descriptive geometry concepts and curves definition. ### How to use insert menu

In order to insert functions such as 'log','exp', etc, while editing, you can select part of the text of the equation using the mouse and click on the built-in function you want to apply it, using the 'insert' menu. In example,  if you wrote x^2+x+1 and want to get x^2+log (x+1): you must paint "x+1" form first equation and click 'logarithm' from insert menu.

### Operators

abs Absolute value ! Factorial
atn Arctangent ^ Power
cos Cosine * Multiply
exp Powered number 'e' / Division
gamma Gamma function \ Integer División (result will be truncated)
inv Inverse - Substract
ln Napierian Logarithm + Add
lngamma Napierian Logarithm of function gamma  Note: All trigonometric functions works with decimal grades..

log Logarithm base 10
sqrt Squared root
trpl Triple root
sin Sine
sgn Sign
tan Tangent

#### Permission enabled

Permission for users to run this software is updated every month.

For more information please check the licence of the product. Donate 5€ to support the author on improving and mainteining this free software. Daniel Manta Barbieri
London, United Kingdom
d_manta@hotmail.com