# plotm3d2.py3   matplotlib  hump
from mpl_toolkits.mplot3d import Axes3D
from matplotlib import pyplot as plt
import numpy as np

print("plotm3d2.py3 running")
fig = plt.figure()
ax = fig.add_subplot(111, projection='3d')

# Create the mesh in polar coordinates and compute corresponding Z.
r = np.linspace(0, 1.25, 25)    # was 50
p = np.linspace(0, 2*np.pi, 25) # was 50
R, P = np.meshgrid(r, p)
Z = ((R**2 - 1)**2)

# Express the mesh in the cartesian system.
#X, Y = R*np.cos(P), R*np.sin(P)
X = R*np.cos(P)
Y = R*np.sin(P)
print("R=", R)
print("P=", P)
print("X=", X)
print("Y=", Y)
print("Z=", Z)

# Plot the surface.
ax.plot_surface(X, Y, Z, cmap=plt.cm.YlGnBu_r)

# Tweak the limits and add latex math labels.
ax.set_zlim(0, 1)
ax.set_title('plotm3d2.py3  hump in valley')
ax.set_xlabel(r'$\phi_\mathrm{real}$')
ax.set_ylabel(r'$\phi_\mathrm{im}$')
ax.set_zlabel(r'$V(\phi)$')

plt.show()
print("plotm3d2.py3 finished")