Next: , Previous: remainder, Up: Math


1.35 scalbn, scalbnf—scale by power of two

Synopsis

     #include <math.h>
     double scalbn(double x, int y);
     float scalbnf(float x, int y);
     

Description
scalbn and scalbnf scale x by n, returning x times 2 to the power n. The result is computed by manipulating the exponent, rather than by actually performing an exponentiation or multiplication.


Returns
x times 2 to the power n.


Portability
Neither scalbn nor scalbnf is required by ANSI C or by the System V Interface Definition (Issue 2).