Hello, I have a data file created by an C++ Programm which creates the lines of the data file by an operation inside an loop Code (C): data3dRnd << gsl_vector_get(x,0) << ' ' << gsl_vector_get(x,1) << ' ' << my_f(x,par) << endl << endl; where the entries of the gsl_vector x are doubles and my_f(x,par) is a double depending on x. I would like to produce a colour plot with x1 and x2 on the axes and show my_f(x,par) via the color of plot. There are some points x where my_f(x,par) produces an Ignore value (1e+300 in this case) and I don't want data points to be plotted which lead to my_f = Ignore value. In a 2D plot of my_f over sqrt(x1^2+x2^2) I achieve this with Code (Text): using 1:($2 < 1e+300 ? $2 : 1/0) How can I achieve this? At first there was only one << endl in my code, but that gave me the error that i need more then one Isoline. So I entered the second << endl as the Isolines are sperated by a blank line. My current Gnuplot Scrit is Code (Text): set terminal eps enhanced set output "VEffCont.eps" set view map set isosamples 100, 100 unset surface set style data pm3d set style function pm3d set ticslevel 0 set title "Random v1 - v2 - Distribution" set xlabel "v1 [GeV]" set ylabel "v2 [GeV]" set pm3d implicit at b set palette cubehelix splot "./3dRnd.dat" u 1:2:3 w pm3d This produces a grid with the correct ranges of x and y axes and a colour scale for my_f but with nothing in the plot window as shown in the attached pdf. Thanks in advance.