scalbn(3) - NetBSD Manual Pages

Command: Section: Arch: Collection:  
SCALBN(3)               NetBSD 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 ħHUGE_VAL, ħHUGE_VALF, or ħHUGE_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 ħ0 or ħInf, 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 7.0 September 18, 2011 NetBSD 7.0
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