我想用
Python制作一个平方根比例图：

但是,我不知道如何制作它. Matplotlib允许制作对数刻度,但在这种情况下我需要像功率函数比例.

最佳答案 您可以创建自己的
ScaleBase课程来完成此任务.为了您的目的,我修改了
here的例子(它制作了一个方形比例,而不是平方根比例).另请参阅文档
here.

请注意,要正确执行此操作,您可能还应创建自己的自定义刻度定位器;我虽然没有这样做;我只是使用ax.set_yticks()手动设置主要和次要刻度.

import matplotlib.scale as mscale
import matplotlib.pyplot as plt
import matplotlib.transforms as mtransforms
import matplotlib.ticker as ticker
import numpy as np

class SquareRootScale(mscale.ScaleBase):
    """
    ScaleBase class for generating square root scale.
    """

    name = 'squareroot'

    def __init__(self, axis, **kwargs):
        mscale.ScaleBase.__init__(self)

    def set_default_locators_and_formatters(self, axis):
        axis.set_major_locator(ticker.AutoLocator())
        axis.set_major_formatter(ticker.ScalarFormatter())
        axis.set_minor_locator(ticker.NullLocator())
        axis.set_minor_formatter(ticker.NullFormatter())

    def limit_range_for_scale(self, vmin, vmax, minpos):
        return  max(0., vmin), vmax

    class SquareRootTransform(mtransforms.Transform):
        input_dims = 1
        output_dims = 1
        is_separable = True

        def transform_non_affine(self, a): 
            return np.array(a)**0.5

        def inverted(self):
            return SquareRootScale.InvertedSquareRootTransform()

    class InvertedSquareRootTransform(mtransforms.Transform):
        input_dims = 1
        output_dims = 1
        is_separable = True

        def transform(self, a):
            return np.array(a)**2

        def inverted(self):
            return SquareRootScale.SquareRootTransform()

    def get_transform(self):
        return self.SquareRootTransform()

mscale.register_scale(SquareRootScale)

fig, ax = plt.subplots(1)

ax.plot(np.arange(0, 9)**2, label='$y=x^2$')
ax.legend()

ax.set_yscale('squareroot')
ax.set_yticks(np.arange(0,9,2)**2)
ax.set_yticks(np.arange(0,8.5,0.5)**2, minor=True)

plt.show()