Gnuplot - how to scale xyrange to not take into account small z in heatmap plot

Question

I have a data file _FullWV.dat and I want Gnuplot to automatically scale xyrange if outside the wanted region z < 10^(-8), is there any way to make it?

Graph is here

Answer 1

Code

set size ratio -1
splot '_FullWV.dat' u (abs($3)<1e-5 ? NaN : $2*cos($1)):($2*sin($1)):3

1e-8 was too small, it cut almost nothing from the original range.

Explanation

abs($3)<1e-5 ? NaN : $2*cos($1)

If z (3rd column) is between -1e-5 and 1e-5, leave x undefined (Not a Number). If x is undefined, no point will be displayed, even if y and z are defined.

If z is outside this range, define x as $2*cos($1).

Note that for pm3d, at least 2 consecutive values are needed for a point to be displayed. It means that 1 lone value will be take into account by autoscale, but will not be displayed.

set size ratio -1

means that one unit on the x scale will be as big as one unit on the y scale : a circle might be displayed as an ellipse otherwise.