# date: 2019.08.26

# https://stackoverflow.com/questions/57661001/how-can-i-plot-a-graph-like-this-one-in-python

# https://jakevdp.github.io/PythonDataScienceHandbook/04.12-three-dimensional-plotting.html

import matplotlib.pyplot as plt

import numpy as np

def u_0(x):

a = 1.0/np.cosh(2.0*(x+8.0))

b = 1.0/np.cosh((x+1.0))

return 8.0*a*a + 2.0*b*b

# spatial grid

N = 100

x = np.linspace(-10, 10, N)

# time

Nt = 100

tlist = np.linspace(0.0, 2.0, Nt)

#velocity

c = 5.0

count = 0

for t in tlist:

u = u_0(x-c*t)

u += count # offset

plt.plot(x, u)

count += 1

plt.savefig("result_2D.png")

plt.show()