Draw relation in matplotlib

Question

I have a relation such as 'x^3 + y^3 + z^3 - c = 0'. c is constant and would be any number, and of course the equation may be changed. How can i draw this surface with python? I don't want to explicit find z=f(x,y)

Answer 1

If you are using Jupyter Notebook and Python, the easiest way that I know of to visualize 3D implicit surfaces is K3D-Jupyter's Marching Cube algorithm.

import k3d
import numpy as np

plot = k3d.plot()

r = 5
zmin, zmax = -r, r
xmin, xmax = -r, r
ymin, ymax = -r, r
N = 100
Nx, Ny, Nz = N, N, N

x = np.linspace(xmin, xmax, Nx, dtype=np.float32)
y = np.linspace(ymin, ymax, Ny, dtype=np.float32)
z = np.linspace(zmin, zmax, Nz, dtype=np.float32)
x, y, z = np.meshgrid(x, y, z, indexing='ij')

p = x**3 + y**3 + z**3 - 2
plt_iso = k3d.marching_cubes(
    p,
    level=0.0, compression_level=9,
    xmin=xmin, xmax=xmax,
    ymin=ymin, ymax=ymax,
    zmin=zmin, zmax=zmax,
    flat_shading=False)
plot += plt_iso
plot.display()