from sympy.interactive import printing
printing.init_printing(use_latex=True)
from sympy import*
import sympy as sp
import matplotlib.pyplot as plt
x, t = sp.symbols('x t')
a, b, c, T = sp.symbols('a b c T')
u = sp.Function('u')(x, t)
u0 = sp.Function('u')(x, 0)
phi = sp.Function('phi')(x, t)
psi = sp.Function('psi')(x)
a = 0.2; b = 2.2; c = -0.4; T = 1.9
#phi = log(17*t) - 2*x
#psi = exp(-x/2)
diffeq = Eq(u.diff(t) - c*u.diff(x), phi)
diffeq1 = Eq(u0, psi)
display(diffeq)
display(diffeq1)
pdsolve(diffeq)
res = pdsolve(diffeq)
from sympy import *
x, b1, b2 = symbols("x b1 b2")
f = x/(x+exp(b1-b2*x))
res = {b1:29.3930964972769,b2:0.327159886574049}
plot(f.subs(res), (x, 0, 100))
Код лучше тут обрамлять тегами, чтоб читабельно было.