Matplotlib.pyplot.quiverkey() in Python

Syntax: matplotlib.pyplot.quiverkey(Q, X, Y, U, label, **kw) Parameters: This method accept the following parameters that are described below:

• Q: This parameter is the Quiver instance returned by a call to quiver.
• X, Y : These parameter are the x and y coordinates of the location of the key.
• U: This parameter is the length of the key.
• label: This parameter is a string with the length and units of the key.
• angles : This parameter is the angle of the arrows.
• color : This parameter is the overrides face and edge colors from Q.
• labelpos : This parameter is used to position the label above, below, to the right, to the left of the arrow.
• labelsep: This parameter is the distance in inches between the arrow and the label.
• labelcolor: This defaults to default Text color.
• fontproperties: This parameter is the dictionary with keyword arguments accepted by the FontProperties initializer: family, style, variant, size, weight.

# Implementation of matplotlib function
import matplotlib.pyplot as plt
import numpy as np
      
X = np.arange(-20, 20, 0.5)
Y = np.arange(-20, 20, 0.5)
U, V = np.meshgrid(X, Y)

q = plt.quiver(X, Y, U, V)
plt.quiverkey(q, X = 0.5, Y = 0.5,
              U = 500, label ='Quiver key')

plt.title('matplotlib.pyplot.quiverkey() Example')
 
plt.show()

# Implementation of matplotlib function
import matplotlib.pyplot as plt
import numpy as np
      
X, Y = np.meshgrid(np.arange(0, 2 * np.pi, .2), np.arange(0, 2 * np.pi, .2))
U = np.cos(X**2)
V = np.sin(Y**2)
C = U**2 + V**2
  
Q = plt.quiver(X, Y, U, V, C, units ='width')
plt.quiverkey(Q, 0.4, 0.9, 1, 
              r'val = $Cos(x ^ 2)^2 + Sin(x ^ 2)^2$',
              labelpos ='E',
              coordinates ='figure')

plt.title('matplotlib.pyplot.quiverkey() Example\n', 
          fontsize = 14, fontweight ='bold')

plt.show()