[Gnuplot-info] unexpected feature when drawing with splot on scattered data

[Jon <dev...@gm...>]

Dear All,

I am trying to use splot to show 3D vision on some dataset. But it seems
give unrealistic peaks at the four corners. The command I used is

set dgrid3d 50,50
sp 'fort.88' u 1:2:3 w pm3d

Somebody told me it could be due to the fitting scheme used to interpolate
through the scattered dataset. Is this the case? If so, how could the
interpolation be turned off and use the simplest linear interpolation only?

By the way, if I only use

sp 'fort.88' u 1:2:3 w l

it's able to give all the subtle details of the data, how should I possibly
do to preserve the honest feature of the data, but give myself a better
view using color and contour?

Thank you very much,

Sincerely,
Jon