在matplotlib直方图的yaxis上调用函数。

I want to format the y-axis of my histogram with the function:

我想用函数来格式化直方图的y轴:

def convertCountToKm2(x):
    return x * 25.0 * 1e-6

Because this converts the histogram y-axis from a cell count to an area in km2. The histogram is created by:

因为这将直方图y轴从细胞计数转换为km2中的面积。直方图由:

bins = numpy.array(list(range(0,7000,1000)))
plt.hist(Anonzero,bins)

Which results in this figure:

结果如下:

I have tried calling the function with the following code:

我尝试用以下代码调用函数:

yFormat = tkr.FuncFormatter(convertCountToKm2)
plt.yaxis.set_major_formatter(yFormat)

which returns an error: module 'matplotlib.pyplot' has no attribute 'yaxis'

返回一个错误:模块'matplotlib。pyplot没有属性“yaxis”

How do I format axis number format to thousands with a comma in matplotlib? seems too have some hints about formatting the axis, but that is not specific for this case. I am unable to use it to answer my question.

如何在matplotlib中使用逗号将轴号格式格式化为数千?似乎也有一些关于格式化轴的提示，但这并不是本例中所特有的。我不能用它来回答我的问题。

1 个解决方案

#1

The error tells you that plt (which I suppose is pyplot) has no yaxis, which is correct. yaxis is an attribute of the axes. Use

这个错误告诉您，plt(我认为是pyplot)没有yaxis，这是正确的。yaxis是坐标轴的一个属性。使用

plt.gca().yaxis.set_major_formatter(...)

Solving this you might run into another problem, that is that functions for the FuncFormatter need to accept two arguments, x, pos. You may ignore pos, but it has to be in the signature

解决这个问题可能会遇到另一个问题，即FuncFormatter的函数需要接受两个参数x、pos

def convertCountToKm2(x, pos=None):
    return x * 25.0 * 1e-6

yFormat = FuncFormatter(convertCountToKm2)
plt.gca().yaxis.set_major_formatter(yFormat)

#1