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.streamplot() function in axes module of matplotlib library is also used to draw streamlines of a vector flow..
Syntax: Axes.streamplot(axes, x, y, u, v, density=1, linewidth=None, color=None, cmap=None, norm=None, arrowsize=1, arrowstyle=’-|>’, minlength=0.1, transform=None, zorder=None, start_points=None, maxlength=4.0, integration_direction=’both’, *, data=None) Parameters: This method accept the following parameters that are described below:
- X, Y : These parameter are the x and y coordinates of the evenly spaced grid.
- U, V: This parameter is the number of rows and columns must match the length of y and x.
- density : This parameter is used to controls the closeness of streamlines.
- linewidth : This parameter is the width of the stream lines.
- color : This parameter is the streamline color.
- cmap : This parameter is used to plot streamlines and arrows.
- norm : This parameter is used to normalize object used to scale luminance data to 0, 1.
- arrowsize : This parameter is the scaling factor for the arrow size.
- minlength : This parameter is the minimum length of streamline in axes coordinates..
- maxlength : This parameter is the maximum length of streamline in axes coordinates.
- zorder : This parameter is the zorder of the stream lines and arrows.
Returns:This method returns the following:
- stream_container :This returns the StreamplotSet Container object with attributes
Below examples illustrate the matplotlib.axes.Axes.streamplot() function in matplotlib.axes: Example 1:
Python3
# Implementation of matplotlib functionimport matplotlib.pyplot as pltimport 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)fig, ax = plt.subplots()ax.streamplot(X, Y, U, V, density =[0.5, 1])ax.set_title('matplotlib.axes.Axes.streamplot()\ Example\n', fontsize = 14, fontweight ='bold')plt.show() |
Output: 
Example 2:
Python3
# Implementation of matplotlib functionimport matplotlib.pyplot as pltimport 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)fig, (ax, ax1)= plt.subplots(nrows = 2, ncols = 1)ax.streamplot(X, Y, U, V, density =[0.5, 1], color = V * U, linewidth = 2, cmap ='autumn')val = np.array([[2, 1, 0, 1, 2, 1], [2, 1, 0, 1, 2, 2]])ax1.streamplot(X, Y, U, V, color = V * U, linewidth = 2, cmap ='autumn', start_points = val.T)ax.set_title('matplotlib.axes.Axes.streamplot() \Example\n', fontsize = 14, fontweight ='bold')plt.show() |
Output: 
