Thanks. Suspected as much re integer vs float. Which brings me to the question: if we are able to debug issues ourselves, should we just post to this list or the devel list or contribute privately.
Thanks, Suresh On Mon, 2 Apr 2007, Eric Firing wrote: > I see where the problem (or at least one problem) is, and I will try to get > it fixed by tomorrow. In the meantime, I think you will get the results you > want by simply converting your arrays to floating point: > > matshow(matrix.astype(float), ...) > > Eric > > Suresh Pillai wrote: > > So I been using the log scale provided by matplotlib.colors.LogNorm, but > > have been seing bizarre behaviour. Basically, high values are not > > displayed properly. I give simple examples below with just two possible > > values in the matrix, but all the same issues arise with more varied > > values. > > > > First notice that the high value (100000) is displayed as being of > > value=1: > > > > from pylab import * > > from matplotlib.colors import LogNorm > > > > matrix = ones((30,30)) > > matrix = matrix*440 > > matrix[29,29] = 100000 > > > > matshow(matrix, norm=LogNorm(vmin=1, vmax=1000000)) > > colorbar() > > show() > > > > The cutoff value for incorrect display (for the scale I am using) seems > > to > > be at 32000: > > > > from pylab import * > > from matplotlib.colors import LogNorm > > > > matrix = ones((30,30)) > > matrix = matrix*440 > > matrix[29,29] = 32000 > > > > matshow(matrix, norm=LogNorm(vmin=1, vmax=1000000)) > > colorbar() > > show() > > > > However, if the value is really high, the color displayed changes again, > > although still not to the correct color (please try with values 918000, > > 920000, and 999000 to see see it progress): > > > > from pylab import * > > from matplotlib.colors import LogNorm > > > > matrix = ones((30,30)) > > matrix = matrix*440 > > matrix[29,29] = 918000 > > > > matshow(matrix, norm=LogNorm(vmin=1, vmax=1000000)) > > colorbar() > > show() > > > > And if one specifies no limits to LogNorm, the colorbar displayed is > > incomplete and the colour displayed is wrong in a different way then when > > specifying the limits (try value = 999000 as well). > > > > from pylab import * > > from matplotlib.colors import LogNorm > > > > matrix = ones((30,30)) > > matrix = matrix*440 > > matrix[29,29] = 918000 > > > > matshow(matrix, norm=LogNorm()) > > colorbar() > > show() > > > > > > Either I am completely missing something or there is a major bug. > > > > I am using mpl checked out from svn on 26 March. > > > > Thanks, > > Suresh > > > > ------------------------------------------------------------------------- > > Take Surveys. Earn Cash. Influence the Future of IT > > Join SourceForge.net's Techsay panel and you'll get the chance to share > > your > > opinions on IT & business topics through brief surveys-and earn cash > > http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV > > _______________________________________________ > > Matplotlib-users mailing list > > Matplotlib-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/matplotlib-users > > ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
