Signum functionsgn(x)={−1,x<00,x=01,x>0sgn(x) = \begin{cases} -1, & {x < 0}\\ 0, & {x = 0}\\ 1, & {x > 0} \end{cases}sgn(x)=⎩⎨⎧−1,0,1,x<0x=0x>0 Sign functionIn mathematics, the sign function or signum function is a function that returns the sign of a real number. In mathematical notation the sign function is often represented as .https://en.wikipedia.org/wiki/Sign_function
