def apply_to(self, expression: Expression) -> List[Expression]:
if not expression.is_integral():
return False
integral_info = IntegralInfo(expression.sympy_expr.function, parse_expr('x'))
subs_rule = substitution_rule(integral_info)
if subs_rule is None:
# Can not be applied by parts
return []
u = subs_rule.u_func
du = Derivative(u, subs_rule.symbol).doit()
variables = [
ExpressionVariable('u', Expression(u)),
ExpressionVariable('du', Expression(du)),
]
equivalent_expression = subs_rule.substep.context.xreplace({subs_rule.u_var: parse_expr('u')})
equivalent_expression = equivalent_expression * subs_rule.constant
result = Expression(f'Integral({str(equivalent_expression)}, u)', variables, is_latex=False)
return [
result
]
def apply_to(self, expression: Expression) -> List[Expression]:
if not expression.is_integral():
return False
integral_info = IntegralInfo(expression.sympy_expr.function,
parse_expr('x'))
by_parts_rule = parts_rule(integral_info)
if by_parts_rule is None:
# Can not be applied by parts
return []
u = by_parts_rule.u
dv = by_parts_rule.dv
v = Integral(dv, by_parts_rule.symbol).doit(
) # TODO Lucas: Buscar si hay una manera menos cochina de hacer esto
variables = [
ExpressionVariable('u(x)', Expression(u)),
ExpressionVariable('v(x)', Expression(v)),
]
equivalent_expression = Expression(
'\\int (u(x) * \\frac{d(v(x))}{dx}) dx', variables)
#main_expression == Expression('x * cos(x) - \\int (\\frac{d(x)}{dx} * cos(x)) dx')
#main_expression = Expression('x * cos(x) - \\int (\\frac{d(x)}{dx} * cos(x)) dx', variables)
# TODO: investigar dx
#Expression('\\int u * \\frac{d(v)}{dx}', variables)
# \\int(x * sen(x)) dx + \\int(x * cos(x)) dx
# \\int(x * sen(x)) dx + POR PARTES(\\int(x * cos(x)) dx)
# POR PARTES(\\int(x * sen(x)) dx) + \\int(x * cos(x)) dx
return [equivalent_expression]
def there_is_a_chance_to_apply_to(self, expression: Expression):
if not expression.is_integral():
return False
integral_info = IntegralInfo(expression.sympy_expr.function, parse_expr('x'))
subs_rule = substitution_rule(integral_info)
return True if subs_rule is not None else False
def test_integrate_is_integral_false(self):
expression = Expression('Derivative(x+x**2,x)', is_latex=False)
self.assertFalse(expression.is_integral())
def test_integrate_is_integral(self):
expression = Expression('Integral(x+x**2,x)', is_latex=False)
self.assertTrue(expression.is_integral())
