Matplotlib.axes.Axes.quiver() in Python

Matplotlib is a library in Python and it is numerical - mathematical extension for NumPy library. The Axes Class contains most of the figure elements: Axis, Tick, Line2D, Text, Polygon, etc., and sets the coordinate system. And the instances of Axes supports callbacks through a callbacks attribute.

The Axes.barbs() function in axes module of matplotlib library is also used to plot a 2D field of arrows.

Syntax: Axes.quiver(self, *args, data=None, **kw Parameters: This method accept the following parameters that are described below:

• X, Y : These parameter are the x and y coordinates of the arrow locations.
• U, V: These parameter are the x and y components of the arrow vector.
• C : This parameter contains the numeric data that defines the arrow colors by colormapping via norm and cmap.
• pivot : This parameter is the part of the arrow that is anchored to the X, Y grid.
• units : This parameter is the arrow dimensions (except for length) are measured in multiples of this unit.
• angles : This parameter is the method for determining the angle of the arrows.
• scale : This parameter is the number of data units per arrow length unit.
• scale_units : This parameter is an optional parameter and it contains these values 'width', 'height', 'dots', 'inches', 'x', 'y', 'xy' .
• width : This parameter is the shaft width in arrow units.
• headwidth : This parameter is the head width as multiple of shaft width.
• headlength : This parameter is the length width as multiple of shaft width.
• headwidth : This parameter is the head width as multiple of shaft width.
• headaxislength : This parameter is the head length at shaft intersection.
• minshaft : This parameter is the length below which arrow scales, in units of head length.
• minlength : This parameter is the minimum length as a multiple of shaft width.
• color : This parameter is the explicit color(s) for the arrows.

Below examples illustrate the matplotlib.axes.Axes.quiver() function in matplotlib.axes: Example 1: 

# 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)

fig, ax = plt.subplots()
q = ax.quiver(X, Y, U, V)

ax.set_title('matplotlib.axes.Axes.quiver()\
 Example', fontsize = 14, fontweight ='bold')
plt.show()

Output: Example 2: 

# 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

fig, ax = plt.subplots()
ax.quiver(X, Y, U, V, C, units ='width')
ax.set_title('matplotlib.axes.Axes.quiver() \
Example', fontsize = 14, fontweight ='bold')
plt.show()

Output: