Eric - Thank you very much. This is exactly what I was looking to do. I should have realized the levels are boundaries, and my color array was not matched to the number of regions. The need for BoundaryNorm makes total sense. Time to stop blindly hacking. Thanks for your example script.
- steve On Jul 14, 2010, at 6:18 PM, Eric Firing wrote: > On 07/14/2010 12:52 PM, Steve McFarlin wrote: >> Hello, >> >> I am trying to create a color map that maps 18 colors across 50 levels. As >> an example let say I have three colors [r,g,b] and want everything between 1 >> an 2 to be r, 3 through 10 to be g, and 11 through 50 to be b. From what I >> can tell it does not seem to be possible. Currently this is what I have, but >> it does not seem to work as I assumed. >> >> colorList = >> [[0.,0.,102./255.],[0,42./255.,217./255.],[0,110./255.,217./255.],[0,178./255.,217./255.], >> >> [0,212./255.,212./255.],[0,217./255.,166./255.],[0,217./255.,0],[149./255.,217./255.,0], >> >> [217./255.,217./255.,0],[217./255.,174./255.,0],[217./255.,131./255.,0],[217./255.,87./255.,0], >> [217./255.,0,0],[174./255.,0,0],[140./255.,0,0],[135./255.,0,0], >> [105./255.,0,0],[65./255.,0,0]] >> >> levels = [1,2,3,4,5,6,7,8,9,10,12,15,20,25,30,35,40,50] >> cmap = matplotlib.colors.ListedColormap(colorList, name = 'theColorMap', N = >> len(colorList)) >> ... >> m.contourf(x,y,z,cmap=cmap, levels=levels, extend='both') >> >> If the levels array is continuous then it works as expected. With the above >> settings I get unexpected results, which includes 'ghost contour lines'. The >> data I am rendering is from a GRIB file from NOAA. > > I think there is some confusion of terminology here, and the "ghost contour > lines" are the least of your problems. > > The contourf "levels" are giving boundaries of regions, so with 18 levels, > you have 17 regions. > > I suspect that what you want is illustrated by the attached extremely simple > example. (You may or may not want to use the spacing kwarg to colorbar.) > > Eric > >> >> Is this possible? >> >> >> Thanks, >> Steve >> ------------------------------------------------------------------------------ >> This SF.net email is sponsored by Sprint >> What will you do first with EVO, the first 4G phone? >> Visit sprint.com/first -- http://p.sf.net/sfu/sprint-com-first >> _______________________________________________ >> Matplotlib-users mailing list >> Matplotlib-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/matplotlib-users > > <contourf_boundary_norm.py>------------------------------------------------------------------------------ > This SF.net email is sponsored by Sprint > What will you do first with EVO, the first 4G phone? > Visit sprint.com/first -- > http://p.sf.net/sfu/sprint-com-first_______________________________________________ > Matplotlib-users mailing list > Matplotlib-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/matplotlib-users ------------------------------------------------------------------------------ This SF.net email is sponsored by Sprint What will you do first with EVO, the first 4G phone? Visit sprint.com/first -- http://p.sf.net/sfu/sprint-com-first _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
