我正在尝试运行 Scipy Cook Book 中的示例，但无法运行。
我正在使用 python 2.7（Numpy 版本 1.6.2，Matplotlib 1.1.1）
代码位于
http://www.scipy.org/Cookbook/Matplotlib/Plotting_Images_with_Special_Values
from matplotlib.colors import Colormap, normalize
#import matplotlib.numerix as nx #In original code changed to numpy in line below
import numpy as nx
from types import IntType, FloatType, ListType
class SentinelMap(Colormap):
def __init__(self, cmap, sentinels={}):
# boilerplate stuff
self.N = cmap.N
self.name = 'SentinelMap'
self.cmap = cmap
self.sentinels = sentinels
for rgb in sentinels.values():
if len(rgb)!=3:
raise ValueError('sentinel color must be RGB')
def __call__(self, scaledImageData, alpha=1):
# assumes the data is already normalized (ignoring sentinels)
# clip to be on the safe side
rgbaValues = self.cmap(nx.clip(scaledImageData, 0.,1.))
#replace sentinel data with sentinel colors
for sentinel,rgb in self.sentinels.items():
r,g,b = rgb
rgbaValues[:,:,0] = nx.where(scaledImageData==sentinel, r, rgbaValues[:,:,0])
rgbaValues[:,:,1] = nx.where(scaledImageData==sentinel, g, rgbaValues[:,:,1])
rgbaValues[:,:,2] = nx.where(scaledImageData==sentinel, b, rgbaValues[:,:,2])
rgbaValues[:,:,3] = nx.where(scaledImageData==sentinel, alpha, rgbaValues[:,:,3])
return rgbaValues
class SentinelNorm(normalize):
"""
Leave the sentinel unchanged
"""
def __init__(self, ignore=[], vmin=None, vmax=None):
self.vmin=vmin
self.vmax=vmax
if type(ignore) in [IntType, FloatType]:
self.ignore = [ignore]
else:
self.ignore = list(ignore)
def __call__(self, value):
vmin = self.vmin
vmax = self.vmax
if type(value) in [IntType, FloatType]:
vtype = 'scalar'
val = array([value])
else:
vtype = 'array'
val = nx.asarray(value)
# if both vmin is None and vmax is None, we'll automatically
# norm the data to vmin/vmax of the actual data, so the
# clipping step won't be needed.
if vmin is None and vmax is None:
needs_clipping = False
else:
needs_clipping = True
if vmin is None or vmax is None:
rval = nx.ravel(val)
#do this if sentinels (values to ignore in data)
if self.ignore:
sortValues=nx.sort(rval)
if vmin is None:
# find the lowest non-sentinel value
for thisVal in sortValues:
if thisVal not in self.ignore:
vmin=thisVal #vmin is the lowest non-sentinel value
break
else:
vmin=0.
if vmax is None:
for thisVal in sortValues[::-1]:
if thisVal not in self.ignore:
vmax=thisVal #vmax is the greatest non-sentinel value
break
else:
vmax=0.
else:
if vmin is None: vmin = min(rval)
if vmax is None: vmax = max(rval)
if vmin > vmax:
raise ValueError("minvalue must be less than or equal to maxvalue")
elif vmin==vmax:
return 0.*value
else:
if needs_clipping:
val = nx.clip(val,vmin, vmax)
result = (1.0/(vmax-vmin))*(val-vmin)
# replace sentinels with original (non-normalized) values
for thisIgnore in self.ignore:
result = nx.where(val==thisIgnore,thisIgnore,result)
if vtype == 'scalar':
result = result[0]
return result
if __name__=="__main__":
import pylab
import matplotlib.colors
n=100
# create a random array
#X = nx.mlab.rand(n,n) # In original cookbook code changed to line below
X = nx.random.rand(n,n)
cmBase = pylab.cm.jet
# plot it array as an image
pylab.figure(1)
pylab.imshow(X, cmap=cmBase, interpolation='nearest')
# define the sentinels
sentinel1 = -10
sentinel2 = 10
# replace some data with sentinels
X[int(.1*n):int(.2*n), int(.5*n):int(.7*n)] = sentinel1
X[int(.6*n):int(.8*n), int(.2*n):int(.3*n)] = sentinel2
# define the colormap and norm
rgb1 = (0.,0.,0.)
rgb2 = (1.,0.,0.)
cmap = SentinelMap(cmBase, sentinels={sentinel1:rgb1,sentinel2:rgb2,})
norm = SentinelNorm(ignore=[sentinel1,sentinel2])
# plot with the modified colormap and norm
pylab.figure(2)
pylab.imshow(X, cmap = cmap, norm=norm, interpolation='nearest')
pylab.show()
但是，我收到一条错误消息
Exception in Tkinter callback
Traceback (most recent call last):
File "C:\Python27\lib\lib-tk\Tkinter.py", line 1410, in __call__
return self.func(*args)
File "C:\Python27\lib\site-packages\matplotlib\backends\backend_tkagg.py", line 236, in resize
self.show()
File "C:\Python27\lib\site-packages\matplotlib\backends\backend_tkagg.py", line 239, in draw
FigureCanvasAgg.draw(self)
File "C:\Python27\lib\site-packages\matplotlib\backends\backend_agg.py", line 421, in draw
self.figure.draw(self.renderer)
File "C:\Python27\lib\site-packages\matplotlib\artist.py", line 55, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "C:\Python27\lib\site-packages\matplotlib\figure.py", line 898, in draw
func(*args)
File "C:\Python27\lib\site-packages\matplotlib\artist.py", line 55, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "C:\Python27\lib\site-packages\matplotlib\axes.py", line 1997, in draw
a.draw(renderer)
File "C:\Python27\lib\site-packages\matplotlib\artist.py", line 55, in draw_wrapper
draw(artist, renderer, *args, **kwargs)
File "C:\Python27\lib\site-packages\matplotlib\image.py", line 350, in draw
im = self.make_image(renderer.get_image_magnification())
File "C:\Python27\lib\site-packages\matplotlib\image.py", line 569, in make_image
transformed_viewLim)
File "C:\Python27\lib\site-packages\matplotlib\image.py", line 201, in _get_unsampled_image
x = self.to_rgba(self._A, bytes=True)
File "C:\Python27\lib\site-packages\matplotlib\cm.py", line 214, in to_rgba
网络搜索使我找到了有关它的评论，但是没有任何用处。
http://www.mail-archive.com/matplotlib-users@lists.sourceforge.net/msg19249.html
希望有人可以帮助我理解问题并找出错误。