Matplotlib中对数轴上的小刻度

时间:2012-09-19 11:28:38

标签: matplotlib

我有一个带对数x轴和y轴的散点图(因为我主要对沿两者的较低值感兴趣)。

但是,我希望刻度标签为十进制格式,而不是10 ^ x。

我用这个:

# axis limits:
ax.set_xlim(xmin=0, xmax = 1.2)
ax.set_ylim(ymin=0,ymax=1000)

# log scales:
ax.set_yscale('log')
ax.set_xscale('log')

# set y-ticks:
ax.set_yticks((1,10,100,1000))
ax.set_yticklabels(("1","10","100","1000"))

这有效(虽然介绍ax.set_yscale('log')ax.set_xscale('log')会发出以下警告(任何想法是什么?):

Warning (from warnings module):
  File "C:\Python27\lib\site-packages\numpy\ma\core.py", line 3785
warnings.warn("Warning: converting a masked element to nan.")
UserWarning: Warning: converting a masked element to nan.

但是当我为x轴尝试相同的时候,我得到一个MaskError:

# set x-ticks:
ax.set_xticks((0, 0.2, 0.4, 0.8, 1))
ax.set_xticklabels(("0", "0.2", "0.4", "0.8", "1"))

[snip long long traceback]
File "C:\Python27\lib\site-packages\numpy\ma\core.py", line 3795, in __int__
  raise MaskError, 'Cannot convert masked element to a Python int.'
MaskError: Cannot convert masked element to a Python int.

我认为这与次要与主要蜱有关。我试图玩自动收报机,但最后总是遇到同样的错误。

我非常感谢任何帮助!

回答后编辑: 通过替换

解决了问题
ax.set_yticks((1,10,100,1000))
ax.set_yticklabels(("1","10","100","1000"))
ax.set_xticks((0, 0.2, 0.4, 0.8, 1))
ax.set_xticklabels(("0", "0.2", "0.4", "0.8", "1"))

ax.yaxis.set_major_formatter(FormatStrFormatter('%1.0f'))
ax.xaxis.set_major_formatter(FormatStrFormatter('%.1f'))
ax.xaxis.set_minor_formatter(FormatStrFormatter('%.1f'))

1 个答案:

答案 0 :(得分:8)

您可以将ticker用作:

import numpy as np
import matplotlib.pyplot as plt
from matplotlib.ticker import FormatStrFormatter

fig = plt.figure(1, [5,4])
ax = fig.add_subplot(111)

ax.plot( range(1,100) , range(1,100) ,  color='#aaaaff')
ax.set_xscale('log')
ax.xaxis.set_major_formatter(FormatStrFormatter('%.03f'))
plt.show()

enter image description here