SGN                      Sign of Number

 y = SGN(numexpr)

    Returns the sign of its numeric argument.

     numexpr    A numeric expression.

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      Notes:    If numexpr is positive, SGN(numexpr) returns 1.

                If numexpr is 0, SGN(numexpr) returns 0.

                If numexpr is negative, SGN(numexpr) returns -1.