I want to draw a contour plot with gnuplot, where I want to point out some special features with special colors.
I define the contour plot by
set pm3d map
set palette defined (-1 "red", -0.1 "red", 0 "white", 0.1 "blue", 1 "blue")
This results in a color gradient which has a small area with a gradient from red to white to blue and the remaining part is red for negative numbers and blue for positive numbers.
My problem is now, that I would like to set gnuplot automatically to a symmetric scaling of the z-axis. But by specifying splot [][][-200:200] 'data' u 1:2:3
and a dataset with values from e.g. -300 to 100 gnuplot does an automatic rescale to [-200:100]
which results in a misalignment of my colorscale (the white area is now around -50).
Is there a way to force a zrange
or get an automatically symmetric scaled axis?