Why it isn't possible to plot array with column dimension other the 3 and 9? I mean it's not possible to plot double[n][m] directly where m is other the 3,9,1,2... Or I missed something?
the dimensions of 6 or 9 corresponds to some special plots like histogram.
see source code of Plot3DPanel class, and you'll see what dimension is adapted to what kind of plot.
I suggest you to migrate to jmathtools.sourceforge.net project which includes a "jmathplot" module with some bug fixes.