Re: Meaning of samples and isosamples with pm3d hidden3d?

[Philipp K. J. <ja...@ie...>]

Try this (all in one consecutive session):

gnuplot> reset
gnuplot> unset surface
gnuplot> unset hidden3d
gnuplot> set xlabel 'x'
gnuplot> set ylabel 'y'
gnuplot> set style line 1000 lt 1
gnuplot> set pm3d implicit hidden3d 1000

gnuplot> set samples 2
gnuplot> set isosamples 2
gnuplot> splot exp(-x**2-y**2)
# totally flat

gnuplot> set samples 3
gnuplot> replot
# Now there are 3 nodes along the x-axis.
# But why? What has set samples to do w/ splot?

gnuplot> set isosamples 2,4
gnuplot> replot
# Now there are still 3 (not 2!) nodes along the x-axis
# and 4 along the y-axis.

That's it. Gnuplot version info is attached to my
original message on this subject.

Best,

		Ph.






On Thursday 21 February 2008 19:47, you wrote:
> On Thursday 21 February 2008 19:06, Philipp K. Janert wrote:
> > When using
> > 	set pm3d hidden3d
> > with splot for plotting a function
> >
> > it seems as if
> > - set samples n
> > 	is used for the number of steps along the x-direction
> > - set isosamples n,m
> > 	uses m for the number of steps along the y-direction
> > 	and ignores n. If only a single argument is given, it is
> > 	used for the y-direction.
>
> I don't think that's right.
> "set isosamples XX,YY"  causes the surface to be represented by
> XX lines with different x, and YY lines with different y.
> Try:
> 	set isosamples 10,50
> 	splot (sin(x)*sin(y))/(x*y)
> 	set isosamples 50,10
> 	replot
>
> So isosamples control the number of lines.
> For hidden surfaces, that's the end of the story so far as I know.
>
> For non-hidden surfaces, "set samples" controls how finely each line is
> sampled. So "set isosamples 5,5"  will give you a small number of lines on
> x and y. "set samples 10,10"  will make these lines very jagged;  "set
> samples 100,100" will make these same lines much smoother.
>
> > I also would expect both arguments to set isosamples to be evaluated.
>
> For me both arguments work as expected.
> Tested both in 4.2 and CVS versions.