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
> matplotlib-users List Signup and Options