Matplotlib.figure.Figure.dpi() in Python

Matplotlib is a library in Python and it is numerical – mathematical extension for NumPy library. The figure module provides the top-level Artist, the Figure, which contains all the plot elements. This module is used to control the default spacing of the subplots and top level container for all plot elements.

matplotlib.figure.Figure.dpi method

The dpi method of figure module of matplotlib library is the resolution in dots per inch.

Syntax: fig.dpi

Parameters: This method does not accept any parameters.

Returns: This method returns resolution in dots per inch.

Below examples illustrate the matplotlib.figure.Figure.dpi function in matplotlib.figure:

Example 1:

# Implementation of matplotlib function
import matplotlib.pyplot as plt
import numpy as np


fig = plt.figure()

nx = int(fig.get_figwidth() * fig.dpi)
ny = int(fig.get_figheight() * fig.dpi)

data = np.random.random((ny, nx))
plt.plot(data)

fig.suptitle('matplotlib.figure.Figure.dpi \
function Example', fontweight ="bold")

plt.show()

Output:

Example 2:

# Implementation of matplotlib function
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)

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

fig.suptitle('matplotlib.figure.Figure.dpi() function\
 Example', fontweight ="bold")

plt.show()

Output: