matplotlib-devel Mailing List for matplotlib

Hi all:
It looks like one can no longer plot an array of RGBA values in imshow - 
I suspect this is a consequence of the recent changes to the way colors 
are handled. For example
from pylab import *
# make a random rgba matrix
rgba = ones((64,64,4),'f')
for k in range(3):
 rgba[:,:,k] = rand(64,64).astype('f')
imshow(rgba)
show()
works in 0.87.2, but fails with
Traceback (most recent call last):
 File "/Users/jsw/lib/python/matplotlib/backends/backend_gtk.py", line 
283, in expose_event
 self._render_figure(self._pixmap, w, h)
 File "/Users/jsw/lib/python/matplotlib/backends/backend_gtkagg.py", 
line 72, in _render_figure
 FigureCanvasAgg.draw(self)
 File "/Users/jsw/lib/python/matplotlib/backends/backend_agg.py", line 
389, in draw
 self.figure.draw(renderer)
 File "/Users/jsw/lib/python/matplotlib/figure.py", line 531, in draw
 for a in self.axes: a.draw(renderer)
 File "/Users/jsw/lib/python/matplotlib/axes.py", line 991, in draw
 im.draw(renderer)
 File "/Users/jsw/lib/python/matplotlib/image.py", line 184, in draw
 im = self.make_image()
 File "/Users/jsw/lib/python/matplotlib/image.py", line 130, in make_image
 im.is_grayscale = (self.cmap.is_gray() and
 File "/Users/jsw/lib/python/matplotlib/colors.py", line 634, in is_gray
 return (alltrue(self._lut[:,0] == self._lut[:,1])
with the latest svn.
This patch to image.py seems to fix it, but I'm not sure it's the right 
solution
--- /Users/jsw/lib/python/matplotlib/image.py.orig 2006年06月02日 
17:04:52.000000000 -0600
+++ /Users/jsw/lib/python/matplotlib/image.py 2006年06月02日 
17:05:24.000000000 -0600
@@ -127,8 +127,10 @@
 im.flipud_in()
 
 im.set_bg( *bg)
- im.is_grayscale = (self.cmap.is_gray() and
- len(self._A.shape) == 2)
+ if len(self._A.shape) == 2:
+ im.is_grayscale = self.cmap.is_gray()
+ else:
+ im.is_grayscale = False
 
 im.set_interpolation(self._interpd[self._interpolation])
-Jeff
-- 
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