# 2D-vlak met verschillende kleuren in 3D omgeving

import matplotlib.pyplot as plt
import numpy as np

from matplotlib import cm
from matplotlib.ticker import LinearLocator

fig, ax = plt.subplots (figsize = (8, 8), subplot_kw = {"projection": "3d"})

E = np.arange (0.65, 1.05, 0.0001)
J = np.arange (1.00, 1.95, 0.0001)

E, J = np.meshgrid (E, J)

D = (-27 * J**2 * E**4 + (36 * J**2 + 4 * J**4) * E**2 - 4 - 8 * J**2 - 4 * J**4) / J**6

ax.set (xlabel = "E", ylabel = "J", zlabel = "D")

surface = ax.plot_surface (E, J, D, cmap = cm.coolwarm)

fig.colorbar (surface, shrink = 0.5, aspect = 7)

plt.show ()