From: Manfred S. <man...@gm...> - 2010-10-06 15:07:56
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> > For me, this new version looks better than the original one, but far > from perfect. > > Look at the attached plot, for the same data set as before. The color > transition > > is partially off by 2 pixel (at the mark "100", and in the range 0-5 > (yellow and > > light green stripes). > > I can reproduce your colorbar using the png terminal. > The break at 100 in particular can also be seen in some other terminal > types, > so I think there must be some rounding issue here. > > However the defects are not visible (or at least much less noticeable) in > the > output from any of the cairo terminals (wxt, pngcairo, pdfcairo), from > emf, > or from PostScript. > Yes, it seems to me that cairo looks OK, apart from the anti-aliasing madness. > So I think the remaining strangeness is specific to the gd.trm terminal. > Do you agree, or are there defects in the other output that my eyes are > not tuned to? > Yes. It is just weird that with my brute force approach (steps=12800) and with my "every pixel" approach both pngcairo and png seemed to be OK, whereas with your more elegant approach only pngcairo gets it right. I really have no clue how the whole thing works, but looking at gd.trm some amount of implicit integer truncation is going on (integer-var = some floating point operation;), so this may contribute to some rounding errors, I don't know. At least it looks better than before, thanks so far. Manfred > cheers, > > Ethan > > (eps and pngcairo output attached) > > > > > > So something strange is going on, still. > > > > Cheers, > > Manfred > > > > > > > It does not, however, fix the problem that if the palette uses only a > limited > > > number of colors (set palette maxcolors N) then these colors are > assigned with > > > even spacing over the whole range. If you would like to have finer > color > > > resolution in one specific part of the range, that's an issue. > > > > > > Ethan > > > > > > > > > -- > Ethan A Merritt > Biomolecular Structure Center, K-428 Health Sciences Bldg > University of Washington, Seattle 98195-7742 -- GMX.ch - Schweizer FreeMail-Dienst mit über 800.000 Mitgliedern E-Mail & mehr! Kostenlos: http://portal.gmx.net/de/go/chfreemail |