_scalb, _scalbl

Remonter à float.h - Index

Header File

float.h

Category

Math Routines

Prototype

double _scalb(double d, long exp);

long double _scalbl(long double ld, long exp);

Description

Scales the argument d by a power of 2.

_scalbl is the long double version; it takes a long double argument and returns a long double result.

Return Value

Returns an exponential value if successful. On overflow (depending on the sign of the argument), the function returns +/– HUGE_VAL; the ERRNO variable is set to ERANGE.

Example

#include <float.h>

int _tmain(int argc, _TCHAR* argv[])
{
  double number;
  long exp;

  /* Request the number and exponent */
  printf("Enter the value and exponent: ");
  scanf("%lf %u", &number, &exp);

  /* Scale the number using */
  printf("Number * (2^Exp) = %lf\n",  _scalb(number, exp));

  return 0;
}

Portability

	POSIX	Win32	ANSI C	ANSI C++
_scalb		+
_scalbl		+