I have just made the commits with the RGB interpolation. As far as I can tell the code all works fine, however I have had some problems with the documentation.
It seems that prior to this commit the documentation build has become broken - at least for Cygwin. Would somebody be able to check it out on a Linux computer as I no longer have access to one. Also Alan, would you like this change listed in the README.release? If so where exactly? Phil On 25 July 2018 at 18:22, Alan W. Irwin <alan.w.irwin1...@gmail.com> wrote: > On 2018-07-25 10:13+0100 Phil Rosenberg wrote: > >> On 24 July 2018 at 20:19, Alan W. Irwin <alan.w.irwin1...@gmail.com> >> wrote: >>> >>> [.... O]one concern I have about the current documentation, is >>> the documentation of the plscmap1la and plscmap1l alt_hue_path >>> argument. That argument makes a lot of sense in HLS space, but does >>> it make any sense at all if you are doing all interpolation in RGB >>> space? That is, should that argument be completely ignored if you are >>> using RGB space interpolation? >> >> >> If I remember correctly, the point of alt_hue_path is specifically to >> determine the direction around the colour wheel for interpolation once >> the rgb values have been converted to hls. When supplying colours in >> hls space, you can specify the direction by using hue values outside >> the range of 0-360, for example specifying the two hues 0 and 240 >> would go from red to blue via yellow, green and cyan, whereas >> specifying the two hues 0 and -120 would go from red to blue via >> magenta. However if you specify rgb colours [1,0,0] and [0,0,1] then >> you can use the alt_hue_path to tell plplot to interpolat backwards >> round the colour wheel. > > > Hi Phil: > > I believe your interpretation of what goes on with this argument for > the HLS case is correct. > >> So moving to rgb interpolation for rgb values makes this variable >> defunct really. > > > I am pretty sure that is the case, but, of course, you should check for the > RGB case in your update to the code that this argument is completely > ignored. > >> I guess the best thing is to simply state this in the >> documentation? > > > Yes. > >> Can we deprecate it somehow and in a future release >> remove it altogether? > > > This would require splitting each of the current plscmap1l and > plscmap1la functions into two in a backwards-incompatible way with one > for the HLS case (where alt_hue_path would be in the argument list) > and one for the RGB case (with no alt_hue_path in the argument list). > Thus, I think our current C API is the best choice so long as you > document that alt_hue_path is ignored for the RGB case. > >> I have made the code changes and am about to test them. I will then >> make the documentation changes and commit the results today. > > > I look forward to seeing that commit. > > > Alan > __________________________ > Alan W. Irwin > > Programming affiliations with the FreeEOS equation-of-state > implementation for stellar interiors (freeeos.sf.net); the Time > Ephemerides project (timeephem.sf.net); PLplot scientific plotting > software package (plplot.sf.net); the libLASi project > (unifont.org/lasi); the Loads of Linux Links project (loll.sf.net); > and the Linux Brochure Project (lbproject.sf.net). > __________________________ > > Linux-powered Science > __________________________ ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Plplot-general mailing list Plplot-general@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/plplot-general
