I have some X Y Z data in a file and I'm using gnuplot to display it. I am creating a heat map, ie. a 2D plot where the Z value is presented using color. Right now I'm using the following script:
set palette defined (0 "blue", 1 "red")
plot "xyz.dat" u $1:$2:$3 w image
My problem is, gnuplot ignores the 0 and 1 in the palette definition. It uses the colors specified, but rescales according to the minimal and maximal Z value in the file. This makes it hard to visually compare different plots whose z range is different.
How do I tell gnuplot to stop rescaling the z color range?