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SCALBN(3)                  Library Functions Manual                  SCALBN(3)

NAME
     scalbn, scalbnf, scalbnl - exponent using FLT_RADIX

LIBRARY
     Math Library (libm, -lm)

SYNOPSIS
     #include <math.h>

     double
     scalbn(double x, int n);

     float
     scalbnf(float x, int n);

     long double
     scalbnl(long double x, int n);

DESCRIPTION
     The scalbn(), scalbnf(), and scalbnl() functions compute x * r^n, where r
     is the radix of the machine's floating point arithmetic, defined by the
     FLT_RADIX constant in <float.h>.  The rationale is efficiency; r^n is not
     computed explicitly.

RETURN VALUES
     As described above, upon successful completion, the described functions
     return the exponent computed using FLT_RADIX.  Otherwise the following
     may occur:

           1.   When the result would cause an overflow, a range error occurs
                and +-HUGE_VAL, +-HUGE_VALF, or +-HUGE_VALL is returned
                according to the sign of x and the return type of the
                corresponding function.

           2.   When the correct value would cause an underflow and it is not
                representable, a range error occurs and either 0.0 or an
                implementation-defined value is returned.  When an underflow
                occurs but the correct value is representable, a range error
                occurs but the correct value is returned.

           3.   If x is ±0 or +-Inf, x is returned.  Likewise, if n is zero,
                x is returned.  If x is NaN, NaN is returned.

SEE ALSO
     exp(3), frexp(3), ldexp(3), math(3)

STANDARDS
     The described functions conform to ISO/IEC 9899:1999 ("ISO C99").

NetBSD 10.99                  September 18, 2011                  NetBSD 10.99