def if_eq_zero(condition, if_result, else_result):
"""
A short expression which can be compiled quickly.
:type condition: Union[float, Symbol]
:type if_result: Union[float, Symbol]
:type else_result: Union[float, Symbol]
:return: if_result if condition == 0 else else_result
:rtype: Union[float, Symbol]
"""
condition = se.Abs(sign(condition))
return (1 - condition) * if_result + condition * else_result
def if_greater_zero(condition, if_result, else_result):
"""
:type condition: Union[float, Symbol]
:type if_result: Union[float, Symbol]
:type else_result: Union[float, Symbol]
:return: if_result if condition > 0 else else_result
:rtype: Union[float, Symbol]
"""
_condition = sign(condition) # 1 or -1
_if = Max(0, _condition) * if_result # 0 or if_result
_else = -Min(0, _condition) * else_result # 0 or else_result
return _if + _else + (1 - Abs(_condition)) * else_result # if_result or else_result
def test_sign():
assert sign(1.2) == 1
assert sign(-1.2) == -1
assert sign(3 * I) == I
assert sign(-3 * I) == -I
assert sign(0) == 0
assert sign(nan) == nan
def fmod(a, b):
s = sign(a)
a = Abs(a)
b = Abs(b)
f1 = a - (b * floor(a / b))
return s * se.Piecewise([0, Abs(a - b) < SMALL_NUMBER], [f1, True])