sign

#sign

##Syntax sign ( r : real ) : -1 .. 1

##Description The sign function is used to determine whether a number is positive, zero or negative. It returns 1 if r > 0, 0 if r = 0, and -1 if r < 0. For example, sign (5) is 1 and sign (-23) is -1.

##Example This program reads in numbers and determines if they are positive, zero or negative:

    var x : real
    get x
    case sign ( x ) of
        label 1 : put "Positive"
        label 0 : put "Zero"
        label -1 : put "Negative"
    end case

##See also See also predefined unit mathmodule.html.