On 15 Nov 2008, at 02:06, Hezekiah M. Carty wrote: > On Fri, Nov 14, 2008 at 7:59 PM, David Seery <[EMAIL PROTECTED]> wrote: >> I would like to produce contour plots in which the contours are >> filled >> with a solid colour. Unfortunately, ... calls to plshades >> produce weirdly segmented images, in which the solid fill is broken >> up >> with unwanted lines, like this: >> >> http://www.damtp.cam.ac.uk/user/djs61/figures.pdf > > This is, at least in part, due to the fact the the plshade functions > in PLplot draw the filled contours as a series of polygons.
Thanks very much for your helpful and comprehensive answer. I had tried to exclude this possibility by checking the output of the png driver, but clearly some mishap occurred (perhaps I looked at the wrong file by mistake). > Vector-based file output (including your example PDF) does not exhibit > this trait if it is viewed from gv with anti-aliasing disabled. > Evince (the default PDF viewer in Ubuntu/Gnome) anti-aliases its > output and does show these inter-polygon lines. I do not know if > these lines show up on a printed version of these PDFs. They don't show up on printed versions, at least on those printers I have access to. The anti-aliasing shows up in the same way using Apple's Preview, which is partly what made me think the effect was real. > I have seen this same issue in output from other plotting packages as > well. One possible workaround is to plot the shaded regions as a > bitmap embedded in the PS/PDF/SVG output. PLplot does not have > support for this directly at this time. However, you can accomplish > this with extra effort using the extcairo driver and a few Cairo > tricks. I can go in to how to do this in more detail if desired. That would be extremely useful if it were possible! I'm trying to produce a graph which is scalable and can be embedded within another document. It probably won't be possible to turn anti-aliasing off when the document is viewed, so this would otherwise seem to be an insurmoutable obstacle. I'm slightly perplexed, because I am sure I have seen plplot output before which contains contiguous shaded regions. Thanks very much, David ------------------------------------------------------------------------- This SF.Net email is sponsored by the Moblin Your Move Developer's challenge Build the coolest Linux based applications with Moblin SDK & win great prizes Grand prize is a trip for two to an Open Source event anywhere in the world http://moblin-contest.org/redirect.php?banner_id=100&url=/ _______________________________________________ Plplot-general mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/plplot-general
