Python Sum.subs Exemples

Exemple #1

Fichier : test_sums_products.py Projet : cbm755/diofant

def test_function_subs():
    f = Function("f")
    s = Sum(x * f(y), (x, 0, oo), (y, 0, oo))
    assert s.subs({f(y): y}) == Sum(x * y, (x, 0, oo), (y, 0, oo))
    assert s.subs({f(x): x}) == s
    pytest.raises(ValueError, lambda: s.subs({f(y): x + y}))
    s = Sum(x * log(y), (x, 0, oo), (y, 0, oo))
    assert s.subs({log(y): y}) == s
    s = Sum(x * f(y), (x, 0, oo), (y, 0, oo))
    assert s.subs({f(y): y}) == Sum(x * y, (x, 0, oo), (y, 0, oo))

Exemple #2

Fichier : test_sums_products.py Projet : skirpichev/diofant

def test_function_subs():
    f = Function("f")
    S = Sum(x*f(y), (x, 0, oo), (y, 0, oo))
    assert S.subs({f(y): y}) == Sum(x*y, (x, 0, oo), (y, 0, oo))
    assert S.subs({f(x): x}) == S
    pytest.raises(ValueError, lambda: S.subs({f(y): x + y}))
    S = Sum(x*log(y), (x, 0, oo), (y, 0, oo))
    assert S.subs({log(y): y}) == S
    S = Sum(x*f(y), (x, 0, oo), (y, 0, oo))
    assert S.subs({f(y): y}) == Sum(x*y, (x, 0, oo), (y, 0, oo))

Exemple #3

Fichier : test_sums_products.py Projet : Blendify/diofant

def test_function_subs():
    f = Function("f")
    S = Sum(x * f(y), (x, 0, oo), (y, 0, oo))
    assert S.subs(f(y), y) == Sum(x * y, (x, 0, oo), (y, 0, oo))
    assert S.subs(f(x), x) == S
    pytest.raises(ValueError, lambda: S.subs(f(y), x + y))
    S = Sum(x * log(y), (x, 0, oo), (y, 0, oo))
    assert S.subs(log(y), y) == S
    S = Sum(x * f(y), (x, 0, oo), (y, 0, oo))
    assert S.subs(f(y), y) == Sum(x * y, (x, 0, oo), (y, 0, oo))