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
implementationdefined 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 6.1.5 September 18, 2011 NetBSD 6.1.5
