Re: Meaning of samples and isosamples with pm3d hidden3d?

[Ethan A M. <merritt@u.washington.edu>]

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. 

-- 
Ethan A Merritt
Biomolecular Structure Center
University of Washington, Seattle 98195-7742