Python matplotlib等高线图对数色标

Question

我使用对数颜色缩放对轮廓图有问题.我想手动指定水平.然而,Matplotlib以一种奇怪的方式绘制颜色条 - 标签放置不好,只出现一种颜色.这个想法基于 http://adversus.110mb.com/?cat=8

那里有人,谁可以帮助我？我使用最新的git-repository matplotlib版本,v1.1.0(2011-04-21)

import matplotlib.pyplot as plt
import numpy as np
from matplotlib.mlab import bivariate_normal
from matplotlib.colors import LogNorm
from matplotlib.backends.backend_pdf import PdfPages


delta = 0.5

x = np.arange(-3.0, 4.001, delta)
y = np.arange(-4.0, 3.001, delta)
X, Y = np.meshgrid(x, y)
Z = bivariate_normal(X, Y, 1.0, 1.0, 0.0, 0.0)

fig  = plt.figure()
ax   = fig.add_subplot(1,1,1)
#axim = ax.imshow(Z, norm = LogNorm())
axim    = ax.contourf(X,Y,Z,levels=[1e0,1e-1,1e-2,1e-3],cmap=plt.cm.jet,norm = LogNorm())
cb   = fig.colorbar(axim)

pp = PdfPages('fig.pdf')
pp.savefig()
pp.close()


plt.show()

非常感谢您的帮助!它的工作原理很完美,正如你所建议的......但是,我有另一个问题:为什么matplotlib不允许我在对数模式中选择水平线的数量:

import matplotlib.pyplot as plt
import numpy as np
from matplotlib.mlab import bivariate_normal
from matplotlib.colors import LogNorm
from matplotlib.backends.backend_pdf import PdfPages


delta = 0.5

x = np.arange(-3.0, 4.001, delta)
y = np.arange(-4.0, 3.001, delta)
X, Y = np.meshgrid(x, y)
Z = bivariate_normal(X, Y, 1.0, 1.0, 0.0, 0.0)

fig  = plt.figure()
ax   = fig.add_subplot(1,1,1)
#axim = ax.imshow(Z, norm = LogNorm())
#axim   = ax.contourf(X,Y,Z,levels=[1e-3,1e-2,1e-1,1e0],cmap=plt.cm.jet,norm = LogNorm())
axim    = ax.contourf(X,Y,Z,20,cmap=plt.cm.jet,norm = LogNorm())
cb   = fig.colorbar(axim)

pp = PdfPages('fig.pdf')
pp.savefig()
pp.close()


plt.show()

http://i.stack.imgur.com/VeVFQ.png

这是我原来的问题......

Answer 1

所以它很容易修复; 你的等级水平意味着最后一级被绘制,因此涵盖了一切!尝试:

axim    = ax.contourf(X,Y,Z,levels=[1e-3, 1e-2, 1e-1, 1e0],cmap=plt.cm.jet,norm = LogNorm())

相反,你应该得到所需的结果.