PSTricks is a set of macros that allow the inclusion of PostScript

PostScript

PostScript is a dynamically typed concatenative programming language created by John Warnock and Charles Geschke in 1982. It is best known for its use as a page description language in the electronic and desktop publishing areas. Adobe PostScript 3 is also the worldwide printing and imaging...

 drawings directly inside TeX

TeX

TeX is a typesetting system designed and mostly written by Donald Knuth and released in 1978. Within the typesetting system, its name is formatted as ....

 or LaTeX

LaTeX

LaTeX is a document markup language and document preparation system for the TeX typesetting program. Within the typesetting system, its name is styled as . The term LaTeX refers only to the language in which documents are written, not to the editor used to write those documents. In order to...

 code.
It is originally the work of Professor Timothy Van Zandt and in recent years it has been maintained by Denis Girou, Sebastian Rahtz and Herbert Voss.
There is a wide list of commands available for making graphics. Coordinates in PSTricks are always represented in round parenthesis as the following example (scaled) illustrates.


\begin{pspicture}(6,6)
%% Triangle in red:
\psline[linecolor=red](1,1)(5,1)(1,4)(1,1)
%% Bezier curve in green:
\pscurve[linecolor=green,linewidth=2pt,%
showpoints=true](5,5)(3,2)(4,4)(2,3)
%% Circle in blue with radius 1:
\pscircle[linecolor=blue,linestyle=dashed](3,2.5){1}
\end{pspicture}

PSTricks commands are low level, so many LaTeX packages have been made in order to ease the creation of several kinds of graphics that are commonly used on mathematical typesetting

Typesetting

Typesetting is the composition of text by means of types.Typesetting requires the prior process of designing a font and storing it in some manner...

.

pst-plot provides commands for creating function

Function (mathematics)

In mathematics, a function associates one quantity, the argument of the function, also known as the input, with another quantity, the value of the function, also known as the output. A function assigns exactly one output to each input. The argument and the value may be real numbers, but they can...

 graphs.