Python draws 3D graphics

This article mainly introduces Python to draw 3D graphics, which has certain reference value. Now I share it with everyone. Friends in need can refer to it

3D graphics are used in data analysis, data modeling, and graphics. It is widely used in fields such as image processing and image processing. Below I will introduce to you how to use python to draw 3D graphics, including the drawing of 3D scatter points, 3D surfaces, 3D contours, 3D straight lines (curves), and 3D text.

Preparation work:

To draw 3D graphics in python, you still use the commonly used drawing module matplotlib, but you need to install the mpl_toolkits toolkit. The installation method is as follows: enter the python installation directory from the windows command line In the Scripts folder, execute: pip install --upgrade matplotlib; execute this command directly in the Linux environment.

After installing this module, you can call the mplot3d class under mpl_tookits to draw 3D graphics.

The following is an example.

1. Drawing of 3D surface shape

from mpl_toolkits.mplot3d import Axes3D 
import matplotlib.pyplot as plt 
import numpy as np 
 
fig = plt.figure() 
ax = fig.add_subplot(111, projection='3d') 
 
# Make data 
u = np.linspace(0, 2 * np.pi, 100) 
v = np.linspace(0, np.pi, 100) 
x = 10 * np.outer(np.cos(u), np.sin(v)) 
y = 10 * np.outer(np.sin(u), np.sin(v)) 
z = 10 * np.outer(np.ones(np.size(u)), np.cos(v)) 
 
# Plot the surface 
ax.plot_surface(x, y, z, color='b') 
 
plt.show()

Spherical surface, the results are as follows:

2. Drawing of 3D straight lines (curves)

import matplotlib as mpl 
from mpl_toolkits.mplot3d import Axes3D 
import numpy as np 
import matplotlib.pyplot as plt 
 
mpl.rcParams['legend.fontsize'] = 10 
 
fig = plt.figure() 
ax = fig.gca(projection='3d') 
theta = np.linspace(-4 * np.pi, 4 * np.pi, 100) 
z = np.linspace(-2, 2, 100) 
r = z**2 + 1 
x = r * np.sin(theta) 
y = r * np.cos(theta) 
ax.plot(x, y, z, label='parametric curve') 
ax.legend() 
 
plt.show()

This code is used to draw a spiral 3D curve. The results are as follows:

3. Draw 3D outline

from mpl_toolkits.mplot3d import axes3d 
import matplotlib.pyplot as plt 
from matplotlib import cm 
 
fig = plt.figure() 
ax = fig.gca(projection='3d') 
X, Y, Z = axes3d.get_test_data(0.05) 
cset = ax.contour(X, Y, Z, zdir='z', offset=-100, cmap=cm.coolwarm) 
cset = ax.contour(X, Y, Z, zdir='x', offset=-40, cmap=cm.coolwarm) 
cset = ax.contour(X, Y, Z, zdir='y', offset=40, cmap=cm.coolwarm) 
 
ax.set_xlabel('X') 
ax.set_xlim(-40, 40) 
ax.set_ylabel('Y') 
ax.set_ylim(-40, 40) 
ax.set_zlabel('Z') 
ax.set_zlim(-100, 100) 
 
plt.show()

The drawing results are as follows:

4. Draw a 3D histogram

from mpl_toolkits.mplot3d import Axes3D 
import matplotlib.pyplot as plt 
import numpy as np 
 
fig = plt.figure() 
ax = fig.add_subplot(111, projection='3d') 
x, y = np.random.rand(2, 100) * 4 
hist, xedges, yedges = np.histogram2d(x, y, bins=4, range=[[0, 4], [0, 4]]) 
 
# Construct arrays for the anchor positions of the 16 bars. 
# Note: np.meshgrid gives arrays in (ny, nx) so we use 'F' to flatten xpos, 
# ypos in column-major order. For numpy >= 1.7, we could instead call meshgrid 
# with indexing='ij'. 
xpos, ypos = np.meshgrid(xedges[:-1] + 0.25, yedges[:-1] + 0.25) 
xpos = xpos.flatten('F') 
ypos = ypos.flatten('F') 
zpos = np.zeros_like(xpos) 
 
# Construct arrays with the dimensions for the 16 bars. 
dx = 0.5 * np.ones_like(zpos) 
dy = dx.copy() 
dz = hist.flatten() 
 
ax.bar3d(xpos, ypos, zpos, dx, dy, dz, color='b', zsort='average') 
 
plt.show()

The drawing results are as follows:

5. Draw 3D mesh lines

from mpl_toolkits.mplot3d import axes3d 
import matplotlib.pyplot as plt 
 
 
fig = plt.figure() 
ax = fig.add_subplot(111, projection='3d') 
 
# Grab some test data. 
X, Y, Z = axes3d.get_test_data(0.05) 
 
# Plot a basic wireframe. 
ax.plot_wireframe(X, Y, Z, rstride=10, cstride=10) 
 
plt.show()

The drawing results are as follows:

6. Draw 3D triangle patch diagram

from mpl_toolkits.mplot3d import Axes3D 
import matplotlib.pyplot as plt 
import numpy as np 
 
 
n_radii = 8 
n_angles = 36 
 
# Make radii and angles spaces (radius r=0 omitted to eliminate duplication). 
radii = np.linspace(0.125, 1.0, n_radii) 
angles = np.linspace(0, 2*np.pi, n_angles, endpoint=False) 
 
# Repeat all angles for each radius. 
angles = np.repeat(angles[..., np.newaxis], n_radii, axis=1) 
 
# Convert polar (radii, angles) coords to cartesian (x, y) coords. 
# (0, 0) is manually added at this stage, so there will be no duplicate 
# points in the (x, y) plane. 
x = np.append(0, (radii*np.cos(angles)).flatten()) 
y = np.append(0, (radii*np.sin(angles)).flatten()) 
 
# Compute z to make the pringle surface. 
z = np.sin(-x*y) 
 
fig = plt.figure() 
ax = fig.gca(projection='3d') 
 
ax.plot_trisurf(x, y, z, linewidth=0.2, antialiased=True) 
 
plt.show(

The drawing results are as follows:

7. Draw a 3D scatter plot

from mpl_toolkits.mplot3d import Axes3D 
import matplotlib.pyplot as plt 
import numpy as np 
 
 
def randrange(n, vmin, vmax): 
 ''''' 
 Helper function to make an array of random numbers having shape (n, ) 
 with each number distributed Uniform(vmin, vmax). 
 ''' 
 return (vmax - vmin)*np.random.rand(n) + vmin 
 
fig = plt.figure() 
ax = fig.add_subplot(111, projection='3d') 
 
n = 100 
 
# For each set of style and range settings, plot n random points in the box 
# defined by x in [23, 32], y in [0, 100], z in [zlow, zhigh]. 
for c, m, zlow, zhigh in [('r', 'o', -50, -25), ('b', '^', -30, -5)]: 
 xs = randrange(n, 23, 32) 
 ys = randrange(n, 0, 100) 
 zs = randrange(n, zlow, zhigh) 
 ax.scatter(xs, ys, zs, c=c, marker=m) 
 
ax.set_xlabel('X Label') 
ax.set_ylabel('Y Label') 
ax.set_zlabel('Z Label') 
 
plt.show()

The drawing results are as follows:

8. Draw 3D text

from mpl_toolkits.mplot3d import Axes3D 
import matplotlib.pyplot as plt 
 
 
fig = plt.figure() 
ax = fig.gca(projection='3d') 
 
# Demo 1: zdir 
zdirs = (None, 'x', 'y', 'z', (1, 1, 0), (1, 1, 1)) 
xs = (1, 4, 4, 9, 4, 1) 
ys = (2, 5, 8, 10, 1, 2) 
zs = (10, 3, 8, 9, 1, 8) 
 
for zdir, x, y, z in zip(zdirs, xs, ys, zs): 
 label = '(%d, %d, %d), dir=%s' % (x, y, z, zdir) 
 ax.text(x, y, z, label, zdir) 
 
# Demo 2: color 
ax.text(9, 0, 0, "red", color='red') 
 
# Demo 3: text2D 
# Placement 0, 0 would be the bottom left, 1, 1 would be the top right. 
ax.text2D(0.05, 0.95, "2D Text", transform=ax.transAxes) 
 
# Tweaking display region and labels 
ax.set_xlim(0, 10) 
ax.set_ylim(0, 10) 
ax.set_zlim(0, 10) 
ax.set_xlabel('X axis') 
ax.set_ylabel('Y axis') 
ax.set_zlabel('Z axis') 
 
plt.show(

The drawing results are as follows:

9. 3D bar graph

from mpl_toolkits.mplot3d import Axes3D 
import matplotlib.pyplot as plt 
import numpy as np 
 
fig = plt.figure() 
ax = fig.add_subplot(111, projection='3d') 
for c, z in zip(['r', 'g', 'b', 'y'], [30, 20, 10, 0]): 
 xs = np.arange(20) 
 ys = np.random.rand(20) 
 
 # You can provide either a single color or an array. To demonstrate this, 
 # the first bar of each set will be colored cyan. 
 cs = [c] * len(xs) 
 cs[0] = 'c' 
 ax.bar(xs, ys, zs=z, zdir='y', color=cs, alpha=0.8) 
 
ax.set_xlabel('X') 
ax.set_ylabel('Y') 
ax.set_zlabel('Z') 
 
plt.show()

The drawing results are as follows:

Related recommendations ：

Use python to draw commonly used charts

Detailed examples of drawing graphics with python

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