Re: [Plplot-general] PS Driver for Image Plots

[Arjen M. <arj...@wl...>]

"Alan W. Irwin" wrote:
> 
> On 2004-11-16 22:23-0700 Curtis Cooper wrote:
> 
> >>> 2) Image plots using the postscript driver come out with streaks across
> >>> the image, as can be seen by running example x16c and saving to a
> >>> postscript driver (either ps or psc).
> >>
> >> What platform and what version of PLplot?  I have never seen such problems
> >> with example 16 on Linux.
> >>
> >
> > This happens in both Debian and Mandrake Linux for the Pentium 4.
> > Using PLplot v. 5.3.1 compiled from the source code tarball on the
> > website.
> 
> Several of our Developers (including me) use Debian testing so that distro
> (and probably Mandrake as well) should be okay for you.  However, now I have
> thought about what you have said some more, I realize my comment above has
> an important qualifier which I failed to state.  Antialiasing must be off in
> the postscript viewer (e.g., gv) to get good looking plots on the screen. Is
> that the problem you refer to here? Try turning antialiasing off in the
> postscript viewer to see whether the problem you are referring to goes away.
> 
> Alan

I had an error report the other day from a Windows user who has a very
similar
problem: on screen the picture looks fine, when saved as a PS file
horizontal
streaks appear.

My first thought (I have not had a chance to analyse this yet) is that
it 
has to do with an integer overflow: the horizontal lines coincide with
items
drawn on the righthand side of the picture, very near the border.

One way to get around it might then be to use a larger margin on the
righthand
side when drawing via PS.

Regards,

Arjen