SGN Function
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 Action

 Indicates the sign of a numeric expression.


 Syntax



  SGN( numeric-expression)

 Remarks


 The  SGN function returns a value depending on the sign of its argument.

   -   If  numeric-expression > 0, then  SGN( numeric-expression) returns 1.

   -   If  numeric-expression = 0, then  SGN( numeric-expression) returns 0.

   -   If  numeric-expression < 0, then  SGN( numeric-expression) returns -1.


 Example

 The following example calculates and prints the solution for the input
 quadratic (or second-degree) equation. The program uses the sign of a test
 expression to determine how to calculate the solution.

 CONST NoRealSoln=-1, OneSoln=0, TwoSolns=1


 ' Input coefficients of quadratic equation.


 ' ax^2 + bx + c = 0.


 INPUT;"a = ",   A


 INPUT;",  b = ",B


 INPUT ",  c = ",C


 Test = B^2 - 4 * A * C


 SELECT CASE SGN(Test)


    CASE  NoRealSoln


       PRINT "This equation has no real-number solutions."


    CASE  OneSoln


       PRINT "This equation has one solution. ";


       PRINT -B-(2 * A)


    CASE  TwoSolns


       PRINT "This equation has two solutions. ";


       PRINT (-B + SQR(Test))-(2 * A) " and ";


       PRINT (-B - SQR(Test))-(2 * A)


 END SELECT




 Output



 a = 3,  b = -4,  c = 1


 This equation has two solutions.  1  and  .3333333