The outcome is usually an array of results which has to be plotted in a graph with an X and Y-axes, X and -ticks, numbers, scaling,colors, linetypes, linethickness, etc.  

In most programming language I know, there are complete libraries for different kind of graphs. 

But I can't find them for Processing. 

Writing them myself seems to be not impossible but a lot of work and, ....most likely...., they already exist. 

Suggestions where to look are highly appreciated! 

Paul