Concatenate array for 3D plotting

[armanditod]

hello everyone,

i am trying to plot this : (first image). It's basically a cylinder with two hemisphere : one on the top of the cylinder and one on the bottom.

I did it by plotting cylinder and the two hemispheres separately. For each, I have 3 arrays : one for X data, one for Y data and one for Z data (so I have 9 array in total).

I would like, to create only 3 arrays that contain :
- one with all X arrays together ;
- one with all Y arrays together ;
- one with all Z arrays together ;
- and plot everything to obtain the same figure ;

I tried with np.concatenate() function but I got this : (second image). We can see that there is a small difference between first and second picture.

How to procede ? Thanks for your help ! :)


Here is my code below :

import numpy as np
import matplotlib.pyplot as plt
from mpl_toolkits.mplot3d import Axes3D

long = 20

fig = plt.figure()
ax = plt.axes(projection='3d')

# PLOTTING CYLINDER

theta = np.linspace(0, 2*np.pi, 100)
z = np.linspace(0, long-2, len(theta))

theta_grid_cylindre, z_grid_cylindre = np.meshgrid(theta, z)

x_grid_cylindre = 1*np.cos(theta_grid_cylindre) + 0
y_grid_cylindre = 1*np.sin(theta_grid_cylindre) + 0
z_grid_cylindre = z_grid_cylindre + 1

#PLOTTING FIRST HEMISPHERE

theta_1 = np.linspace(0, np.pi/2, 100)

x, y = np.meshgrid(theta, theta_1)

x_grid_sphere = np.cos(x)*np.sin(y)
y_grid_sphere = np.sin(x)*np.sin(y)
z_grid_sphere = np.cos(y)+long-1

#PLOTTING SECOND HEMISPHERE

theta_2 = np.linspace(0, np.pi/2, 100)

x_bas, y_bas = np.meshgrid(theta, theta_2)

x_grid_sphere_bas = np.cos(x_bas)*np.sin(y_bas)
y_grid_sphere_bas = np.sin(x_bas)*np.sin(y_bas)
z_grid_sphere_bas = -np.cos(y_bas)+1

# TRYING TO CONCATENATE ALL ARRAY
 
test_x = np.concatenate((x_grid_sphere,x_grid_cylindre,x_grid_sphere_bas),axis=1)
test_y = np.concatenate((y_grid_sphere,y_grid_cylindre,y_grid_sphere_bas),axis=1)
test_z = np.concatenate((z_grid_sphere,z_grid_cylindre,z_grid_sphere_bas),axis=1)

# PLOTTING EACH PIECE SEPARATELY

ax.plot_surface(x_grid_sphere, y_grid_sphere,z_grid_sphere, color ="green", alpha=0.5)
ax.plot_surface(x_grid_cylindre, y_grid_cylindre,z_grid_cylindre, color ="green", alpha=0.5)
ax.plot_surface(x_grid_sphere_bas, y_grid_sphere_bas,z_grid_sphere_bas, color ="green", alpha=0.5)

# TRYING TO PLOT ALL IN ONE

ax.plot_surface(test_x,test_y,test_z, color ="green", alpha=0.5)

plt.show()

deanhystad write Mar-20-2024, 03:04 PM:
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