Matplotlib.axes.Axes.contains_point() in Python

Matplotlib is a library in Python and it is numerical – mathematical extension for NumPy library. The Axes Class contains most of the figure elements: Axis, Tick, Line2D, Text, Polygon, etc., and sets the coordinate system. And the instances of Axes supports callbacks through a callbacks attribute.

matplotlib.axes.Axes.contains_point() Function

The Axes.contains_point() function in axes module of matplotlib library is used to return whether point (pair of pixel coordinates) is inside the axes patch.

Syntax: Axes.contains_point(self, point)

Parameters: This method accept only one parameters.

• point : This parameter is the pair of pixel coordinates.

Returns: This method returns the boolean value.

Below examples illustrate the matplotlib.axes.Axes.contains_point() function in matplotlib.axes:

Example 1:

# Implementation of matplotlib function
import numpy as np
import matplotlib.cm as cm
import matplotlib.pyplot as plt
import matplotlib.cbook as cbook
from matplotlib.path import Path
from matplotlib.patches import PathPatch


delta = 0.025
x = y = np.arange(-3.0, 3.0, delta)
X, Y = np.meshgrid(x, y)
Z1 = np.exp(-X**2 - Y**2)
Z2 = np.exp(-(X - 1)**2 - (Y - 1)**2)
Z = (Z1 - Z2) * 2

path = Path([[0, 1], [1, 0], [0, -1],
             [-1, 0], [0, 1]])
patch = PathPatch(path, facecolor ='none')

fig, ax = plt.subplots()
ax.add_patch(patch)

im = ax.imshow(Z,
               interpolation ='bilinear',
               cmap = cm.gray,
               origin ='lower',
               extent =[-3, 3, -3, 3],
               clip_path = patch,
               clip_on = True)

im.set_clip_path(patch)

ax.text(-1.2, 2,
        "Value Return : "+ str(path.contains_point([0, 0])),
        fontweight ="bold",
        fontsize = 10)

fig.suptitle('matplotlib.axes.Axes.contains_point() \
function Example', fontweight ="bold")

plt.show()

Output:

Example 2:

# Implementation of matplotlib function
import matplotlib.pyplot as plt
from matplotlib.path import Path
import matplotlib.patches as patches


verts = [(0., 0.), (0., 1.),
         (1., 1.), (1., 0.),
         (0., 0.)]

codes = [Path.MOVETO, Path.LINETO,
         Path.LINETO, Path.LINETO, Path.CLOSEPOLY]

path = Path(verts, codes)

fig, ax = plt.subplots()
patch = patches.PathPatch(path, facecolor ='green', lw = 2)
ax.add_patch(patch)
ax.set_xlim(-0.5, 2)
ax.set_ylim(-0.5, 2)

ax.text(0, 1.2,
        "Value Return : "+ str(path.contains_point([5, 5])),
        fontweight ="bold",
        fontsize = 10)

fig.suptitle('matplotlib.axes.Axes.contains_point()\
function Example', fontweight ="bold")

plt.show()

Output: