Matplotlib.patches.Circle class in Python

Last Updated : 27 Apr, 2020

Matplotlib is an amazing visualization library in Python for 2D plots of arrays. Matplotlib is a multi-platform data visualization library built on NumPy arrays and designed to work with the broader SciPy stack.

matplotlib.patches.Circle

The matplotlib.patches.Circle class is used to create a circular patch at a given center xy = (x, y) with a given radius. It uses Bezier splines and is much closer to a scale-free circle.

Syntax: class matplotlib.patches.Circle(xy, radius=5, **kwargs) parameters:

xy: It is the center of the circle.
radius: It sets the radius of the circle to be drawn. Its default value is 5 units and is optional.

Below table provides with the optional valid kwargs ;

PROPERTY	DESCRIPTION
agg_filter	a filter function that takes a (m, n, 3) float array and a dpi value that returns a (m, n, 3) array
alpha	float or None
animated	bool
antialiased or aa	unknown
capstyle	{‘butt’, ’round’, ‘projecting’}
clip_box	Bbox
clip_on	bool
clip_path	[(Path, Transform)\|Patch\|None]
color	color or sequence of rgba tuples
contains	callable
edgecolor or ec or edgecolors	color or None or ‘auto’
facecolor or fc or facecolors	color or None
figure	figure
fill	bool
gid	str
hatch	{‘/’, ‘\’, ‘\|’, ‘-‘, ‘+’, ‘x’, ‘o’, ‘O’, ‘.’, ‘*’}
in_layout	bool
joinstyle	{‘miter’, ’round’, ‘bevel’}
linestyle or ls	{‘-‘, ‘–‘, ‘-.’, ‘:’, ”, (offset, on-off-seq), …}
linewidth or linewidths or lw	float or None
path_effects	AbstractPathEffect
picker	None or bool or float or callable
path_effects	AbstractPathEffect
picker	float or callable[[Artist, Event], Tuple[bool, dict]]
rasterized	bool or None
sketch_params	(scale: float, length: float, randomness: float)
snap	bool or None
transform	matplotlib.transforms.Transform
url	str
visible	bool
zorder	float

Example 1:

Python3 1==

import numpy as np
from matplotlib.patches import Circle
from matplotlib.collections import PatchCollection
import matplotlib.pyplot as plt
from matplotlib import cm
from matplotlib import animation


fig, ax = plt.subplots()

patches = []
# create circles with random sizes 
# and locations
N = 12 # number of circles
x = np.random.rand(N)
y = np.random.rand(N)
radii = 0.1 * np.random.rand(N)
for x1, y1, r in zip(x, y, radii):
    circle = Circle((x1, y1), r)
    patches.append(circle)

# add these circles to a collection
p = PatchCollection(patches, cmap = cm.prism, alpha = 0.4)
ax.add_collection(p)

def animate(i):
    
    # random index to color map
    colors = 100 * np.random.rand(len(patches))
    
    # set new color colors
    p.set_array(np.array(colors))
    return p,

ani = animation.FuncAnimation(fig, animate,
                              frames = 50, interval = 50)

plt.show()

Output:

Example 2:

Python3 1==

import numpy as np
import matplotlib
from matplotlib.patches import Circle, Wedge, Polygon, Ellipse
from matplotlib.collections import PatchCollection
import matplotlib.pyplot as plt
import matplotlib.patches as matpatches


fig, ax = plt.subplots(figsize =(8, 8))
patches = []


circle = Circle((2, 2), 2)
patches.append(circle)

polygon = matpatches.PathPatch(patches[0].get_path())
patches.append(polygon)


colors = 2 * np.random.rand(len(patches))
p = PatchCollection(patches,
                    cmap = matplotlib.cm.jet,
                    alpha = 0.4)

p.set_array(np.array(colors))
ax.add_collection(p)

plt.axis([-10, 10, -10, 10])

plt.show()


contain2 = patches[0].get_path().contains_points([[0.5, 0.5], 
                                                  [1.0, 1.0]])
contain3 = patches[0].contains_point([0.5, 0.5])
contain4 = patches[0].contains_point([1.0, 1.0])