从matplotlib刻度标签格式中删除前导0

Question

如何更改数字十进制数据的ticklabels为"0","0.1" (在0和1之间的说),在matplotlib" 0.2" ,而不是'0.0’,'0.1’,'0.2’？例如,

hist(rand(100))
xticks([0, .2, .4, .6, .8])

将标签格式化为"0.0","0.2"等.我知道这摆脱了"0.0"中的前导"0"和"1.0"上的尾随"0":

from matplotlib.ticker import FormatStrFormatter
majorFormatter = FormatStrFormatter('%g')
myaxis.xaxis.set_major_formatter(majorFormatter) 

这是一个好的开始,但我也想摆脱"0.2"和"0.4"等的"0"前缀.如何做到这一点？

Answer 1

虽然我不确定这是最好的方法,但你可以使用a matplotlib.ticker.FuncFormatter来做到这一点.例如,定义以下函数.

def my_formatter(x, pos):
    """Format 1 as 1, 0 as 0, and all values whose absolute values is between
    0 and 1 without the leading "0." (e.g., 0.7 is formatted as .7 and -0.4 is
    formatted as -.4)."""
    val_str = '{:g}'.format(x)
    if np.abs(x) > 0 and np.abs(x) < 1:
        return val_str.replace("0", "", 1)
    else:
        return val_str

现在,您可以使用majorFormatter = FuncFormatter(my_formatter)替换majorFormatter问题.

完整的例子

让我们看一个完整的例子.

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

def my_formatter(x, pos):
    """Format 1 as 1, 0 as 0, and all values whose absolute values is between
    0 and 1 without the leading "0." (e.g., 0.7 is formatted as .7 and -0.4 is
    formatted as -.4)."""
    val_str = '{:g}'.format(x)
    if np.abs(x) > 0 and np.abs(x) < 1:
        return val_str.replace("0", "", 1)
    else:
        return val_str

# Generate some data.
np.random.seed(1) # So you can reproduce these results.
vals = np.random.rand((1000))

# Set up the formatter.
major_formatter = FuncFormatter(my_formatter)

plt.hist(vals, bins=100)
ax = plt.subplot(111)
ax.xaxis.set_major_formatter(major_formatter)
plt.show()

运行此代码会生成以下直方图.

请注意,刻度标签满足问题中要求的条件.