使用 matplotlib 仅在圆圈内绘制绘图

Question

我有分散的数据，我正在将其插值到网格化数据中。之后我用 contourf 函数绘制所有内容。最后我只想在定义的圆圈内绘制所有内容。其他的都应该是白色的，但我不知道如何实现。有没有简单的方法可以做到这一点？

这是我的代码：

import numpy as np
import matplotlib.pyplot as plt
from scipy.interpolate import griddata


def func(x, y):
  return x*(1-x)*np.cos(4*np.pi*x) * np.sin(4*np.pi*y**2)**2

grid_x, grid_y = np.mgrid[0:1:100j, 0:1:200j]

points = np.random.rand(1000, 2)
values = func(points[:,0], points[:,1])


grid_z0 = griddata(points, values, (grid_x, grid_y), method='nearest')

plt.contourf(grid_x,grid_y,grid_z0)

plt.savefig("plot_data_in_circle.png")

编辑：我附上了我的代码中的情节：

它应该是这样的：

Answer 1

这可以通过创建一个 Circle 补丁，然后将其设置为 clip_path。

要使用 clip_path，通常会存储要应用剪辑的艺术家，然后在其上使用 .set_clip_path。在这种情况下，因为您使用的是 contourf, there is no method .set_clip_path, so we have to iterate over the PathCollections stored with the QuadContourSet returned from contourf, and set the clip path on each of them using the set_clip_path method。

import numpy as np
import matplotlib.pyplot as plt
from scipy.interpolate import griddata
import matplotlib.patches as patches

def func(x, y):
  return x*(1-x)*np.cos(4*np.pi*x) * np.sin(4*np.pi*y**2)**2

grid_x, grid_y = np.mgrid[0:1:100j, 0:1:200j]

points = np.random.rand(1000, 2)
values = func(points[:,0], points[:,1])


grid_z0 = griddata(points, values, (grid_x, grid_y), method='nearest')

fig, ax = plt.subplots()
cs = ax.contourf(grid_x,grid_y,grid_z0)

circ = patches.Circle((0.6, 0.4), 0.3, transform=ax.transData)
for coll in cs.collections:
    coll.set_clip_path(circ)

plt.show()

使用 matplotlib 仅在圆圈内绘制绘图

Draw plot only inside a circle with matplotlib

python

interpolation

numpy

matplotlib

draw