Matplotlib Tutorial

Matplotlib - Figure Class



Matplotlib contains a Figure class in the matplotlib.figure module. It is a top-level container for all plot elements. The Figure object is instantiated by calling the figure() function from the pyplot module. It is a state-based interface (pyplot module) in Matplotlib Library.

figure() Function

To create a new figure the figure() function of the pyplot module is used in the matplotlib library. The syntax for using this function is given below:

class matplotlib.figure.Figure(
                     figsize=None, dpi=None, 
                     facecolor=None, edgecolor=None, 
                     linewidth=0.0, frameon=None)

Parameters

figsize Optional. Specify figure dimension (width, height) in inches. Default is [6.4, 4.8].
dpi Optional. Specify dots per inch. Default is 100.0.
facecolor Optional. Specify the figure patch facecolor. Default is 'white'.
edgecolor Optional. Specify the figure patch edge color. Default is 'white'.
linewidth Optional. Specify the linewidth of the frame.
linewidth Optional. If False, suppress drawing the figure background patch. Default is True.

Example: simple plot

In the example below, figure() function is used create a figure object which is further used to draw a plot of y = sin(x).

import matplotlib.pyplot as plt
import numpy as np

#creating a array of values between
#0 to 10 with a difference of 0.1
x = np.arange(0, 10, 0.1)
y = np.sin(x)

#creating figure object
fig = plt.figure()
#creating axes object
ax = fig.add_axes([0.15,0.1,0.8,0.8])

#formatting axes
ax.set_title("Sine wave")
ax.set_xlabel("x")
ax.set_ylabel("y = sin(x)")

#drawing the plot
ax.plot(x, y)

#displaying the figure
plt.show()

The output of the above code will be:

Figure Class

Example: customizing the figure object

Consider one more example where parameters of figure() function are used to customize the figure object.

import matplotlib.pyplot as plt
import numpy as np

#creating a array of values between
#0 to 10 with a difference of 0.1
x = np.arange(0, 10, 0.1)
y = np.sin(x)

#creating figure object
fig = plt.figure(figsize = [10, 5], facecolor = 'grey')
#creating axes object
ax = fig.add_axes([0.1,0.1,0.8,0.8])

#formatting axes
ax.set_title("Sine wave")
ax.set_xlabel("x")
ax.set_ylabel("y = sin(x)")

#drawing the plot
ax.plot(x, y)

#displaying the figure
plt.show()

The output of the above code will be:

Figure Class

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