matplotlib use in python (c)

Some other graphics

1), grayscale

def f(x_, y_): 
    return (1 - x_ / 2 + x_ ** 5 + y_ ** 3) * np.exp(-x_ ** 2 - y_ ** 2)
n = 5
x = np.linspace(-2, 3, 3 * n)
y = np.linspace(-2, 3, 2 * n)
X, Y = np.meshgrid(x, y)
plt.imshow(f(X, Y))
plt.show()

Wherein the meshgrid()generated mesh.
Results are as follows:

2), 3D FIG (plot_surface)

from mpl_toolkits.mplot3d import Axes3D

fig = plt.figure()
ax = Axes3D(fig)
X = np.arange(-4, 4, 0.25)
Y = np.arange(-4, 4, 0.25)
X, Y = np.meshgrid(X, Y)
R = np.sqrt(X ** 2  + Y ** 2)
Z = np.cos(R)
ax.plot_surface(X, Y, Z, rstride=1, cstride=1, cmap='hot')
plt.show()

• rstrideFringe spacing in the x-direction, an interval of 0.25 to x, the default value is 1.
• cstrideFringe spacing in y direction, a y-direction spacing of 0.25, a default value.

Results are as follows:

3), the amount of field pattern (Quiver)

n = 10
X, Y = np.mgrid[0:n, 0:n]
plt.quiver(X, Y,color = 'R')
plt.show()

np.mgrid()Generating 2D, 3D matrix: The number of rows is determined by the first parameter np.mgrid, the number of columns is determined by the first parameter np.mgrid, filled by using the broadcast mechanism.

Results are as follows:

4), the contour (contourf, contour)

def f(x_, y_):
    return (1 - x_ / 2 + x_ ** 5 + y_ ** 3) * np.exp(-x_ ** 2 - y_ ** 2)


n = 256
x = np.linspace(-1, 3, n)
y = np.linspace(-1, 3, n)
X, Y = np.meshgrid(x, y)

plt.contourf(X, Y, f(X, Y), 4, alpha=.75, cmap='jet')
plt.contour(X, Y, f(X, Y), 4, colors='black', linewidth=.5)
plt.show()

coutour([X, Y,] Z,[levels], **kwargs)

• contourfDraw filled outline:

parameter	Introduction
X, Y	Similar arrays, optional
FROM	Highly value matrix-like, draw the outline of
levels	int array or the like, alternatively, determining the number and location of the contour line / area
Alf	float, optionally, alpha blending value between 0 (transparent) and 1 (opaque)
cmap	str or colormap, optional
Colormap	For data values ​​(floating point) converted from the spacer to the respective Colormap RGBA color representation, the data for scaling the spacing viewed

PS:
When X, Y, Z is a 2-dimensional array, they must have the same shape. If both 1-dimensional array, len (X) Z is the number of columns, while len (Y) is the number of rows in Z.

• contourDraw contour parameters above.

Results are as follows:

Reference Code:

https://github.com/ZhangJiangtao-0108/python in the matplotlib_example.pyfile