i'm not sure if you are still interested in a solution to your problem, since it's been a long time since your post. anyway, i think it's this thing causing the problem: "(colourB=0, r=radius0.75, fx(t)),fy(t) with filledcurves linestyle 2," i rewrote your code to the following and it works: plot \ for [i=0:rowf-rowi] '+' using (xpos):(ypos(i)) with points pointtype 5 pointsize 4 linecolor i+1 , \ for [i=0:rowf-rowi] filename using (xpos):(ypos(i)):(sprintf('%s(%s)', stringcolumn(1), stringcolumn(2)))...