import matplotlib.path as mpath
import matplotlib.patches as mpatches
import matplotlib.pyplot as plt
import numpy as np

v_in = 8
a = 0.75
a2 = 2
a3 = 3
b = 7
r = np.arange(a, b, 0.125)
E = v_in / (r * np.log(r / a))
E2 = v_in / (r * np.log(r / a2))
E3 = v_in / (r * np.log(r / a3))

plt.semilogy(r, E, label=str(a))
plt.semilogy(r, E2, label=str(a2))
plt.semilogy(r, E3, label=str(a3))
plt.legend()
plt.title('E field in glass reactor from center to outside.')
plt.xlabel('radius [mm]')
plt.ylabel('E-field (log) [kV/mm]')
plt.grid()
plt.axhline(0.5)
plt.axhline(1.2)
plt.axhline(0.85)
plt.show()
