[Gnuplot-info] How to plot directly in unit of pixels by gnuplot?

[Fayer M. <fay...@gm...>]

Expect for canvas size, gnuplot uses relative unit to plot. Now I want
to draw directly in unit of pixels. For example, I want something like:
  set obj rect from 100,20 to 200,30 fc palette cb 3

where 100,20 and 200,30 are in pixel.

I set xrange/yrange to something like 1:640 and 1:480, and set all
margins to 0. However, the results were still not exactly what I want.
And it's a dirty hack. Anyone knows a clean one?

I noticed low-level Perl package Term::Gnuplot, but it's not convenient
for high-level plotting.

Fayer