Matplotlib.artist.Artist.get_transform() in Python

Matplotlib is a library in Python and it is numerical – mathematical extension for NumPy library. The Artist class contains Abstract base class for objects that render into a FigureCanvas. All visible elements in a figure are subclasses of Artist.

Matplotlib.artist.Artist.get_transform() Method

The get_transform() method in artist module of matplotlib library is used to get the Transform instance used by this artist

Syntax: Artist.get_transform(self)

Parameters: This method does not accepts any parameter.

Returns: This method return the Transform instance used by this artist

Below examples illustrate the matplotlib.artist.Artist.get_transform() function in matplotlib:

Example 1:

# Implementation of matplotlib function
from matplotlib.artist import Artist
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.transforms as mtransforms


fig, ax = plt.subplots()

l1, = ax.plot([0.1, 0.5, 0.9],
              [0.1, 0.9, 0.5],
              "bo-")

l2, = ax.plot([0.1, 0.5, 0.9],
              [0.5, 0.2, 0.7],
              "ro-")

for l in [l1, l2]:
    xx = l.get_xdata()
    yy = l.get_ydata()
    shadow, = ax.plot(xx, yy)
    shadow.update_from(l)

    ot = mtransforms.offset_copy(Artist.get_transform(l),
                                 ax.figure,
                                 x = 4.0, y =-6.0,
                                 units ='points')

    shadow.set_transform(ot)

plt.title("""matplotlib.artist.Artist.get_transform()
function Example""", fontweight="bold")

plt.show()

Output:

Example 2:

# Implementation of matplotlib function
from matplotlib.artist import Artist
import matplotlib.pyplot as plt
from matplotlib import collections, colors, transforms
import numpy as np


nverts = 50
npts = 100

r = np.arange(nverts)
theta = np.linspace(0, 2 * np.pi, nverts)

xx = r * np.sin(theta)
yy = r * np.cos(theta)
spiral = np.column_stack([xx, yy])

rs = np.random.RandomState(19680801)

xyo = rs.randn(npts, 2)

colors = [colors.to_rgba(c)
          for c in plt.rcParams['axes.prop_cycle'].by_key()['color']]

fig, ax1 = plt.subplots()

col = collections.RegularPolyCollection(
    7, sizes = np.abs(xx) * 10.0,
    offsets = xyo,
    transOffset = ax1.transData)

trans = transforms.Affine2D().scale(fig.dpi / 72.0)
Artist.set_transform(col, trans)

ax1.add_collection(col, autolim = True)
col.set_color(colors)

plt.title("""matplotlib.artist.Artist.set_transform()
function Example""", fontweight="bold")

plt.show()

Output:

Value Return by get_transform() :
 Affine2D(
    [[1.38888889 0.         0.        ]
     [0.         1.38888889 0.        ]
     [0.         0.         1.        ]])