matplotlib - 3d surface from a rectangular array of heights

Question

I am trying to plot some HDF data in matplotlib. After importing them using h5py, the data is stored in a form of array, like this:

array([[151, 176, 178],
          


        

Answer 1

If you want a 3-d surface plot, you have to create the meshgrid first. You can try:

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

X = np.arange(1, 10)
Y = np.arange(1, 10)
X, Y = np.meshgrid(X, Y)
R = np.sqrt(X**2 + Y**2)
Z = np.sin(R)
fig = plt.figure()
ax = fig.gca(projection='3d')
surf = ax.plot_surface(X, Y, Z, rstride=1, cstride=1, cmap='hot', linewidth=0, antialiased=False)
ax.set_zlim(-1.01, 1.01)

fig.colorbar(surf, shrink=0.5, aspect=5)
plt.show()

which will generate,

However, if the only relevant information is in the z-values, you can simply use imshow. Here, z-values are represented by their color. You can achieve this by:

im = plt.imshow(Z, cmap='hot')
plt.colorbar(im, orientation='horizontal')
plt.show()

Which will give,