Код: Выделить всё
from sympy import Function, Symbol
from sympy.printing import pprint
x = Symbol(name="x", real=True)
h = Symbol(name="h", positive=True)
u = Function("u")
def forward(x):
return (u(x + h) - u(x)) / h
def backward(x):
return (u(x) - u(x - h)) / h
def centered(x):
return (u(x + h) - u(x - h)) / (2 * h)
def symmetric(x):
return (u(x - h) - 2 * u(x) + u(x + h)) / h**2
def compose(f, g):
return lambda x: f(g(x))
pprint(forward(x))
pprint(backward(x))
pprint(centered(x))
pprint(symmetric(x))

Подробнее здесь: https://stackoverflow.com/questions/790 ... s-in-sympy