Function abs
pub fn abs<T: TapeStorage>(x: &AReal<T>) -> AReal<T>Expand description
Absolute value. f' = sign(x), f'' = 0 (away from 0). At x = 0 the derivative is not defined; every surface takes the sub-gradient f'(0) = +1 (the x >= 0 branch), matching the winning-branch convention max/min use for payoffs.