Set up a plot grid with cols by rows subwindows and plot in location given by index.
If only one argument is supplied, then it must be a three digit value specifying the location in digits 1 (rows) and 2 (columns) and the plot index in digit 3.
The plot index runs row-wise. First all the columns in a row are filled and then the next row is filled.
For example, a plot with 2 by 3 grid will have plot indices running as follows:
See also: plot