Python中的 Matplotlib.axes.Axes.streamplot()

Matplotlib是Python中的一个库，它是 NumPy 库的数值数学扩展。 Axes 类包含大部分图形元素：Axis、Tick、Line2D、Text、Polygon 等，并设置坐标系。 Axes 的实例通过回调属性支持回调。

matplotlib.axes.Axes.streamplot()函数

matplotlib 库的 axes 模块中的Axes.streamplot()函数也用于绘制矢量流的流线。

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 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

编程需要懂一点英语

下面的示例说明了 matplotlib.axes 中的 matplotlib.axes.Axes.streamplot()函数：

示例 1：

# 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)
  
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()

输出：

示例 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)
  
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()

输出：