6.11.160 scalbln Function

Calculates the signed exponent of a double precision floating-point value.

Include

<math.h>

Prototype

double scalbln(double x, long int n);

Arguments

x

multiplier

n

the power to which FLT_RADIX is raised

Return Value

Efficiently calculates and returns the value of x times FLT_RADIXn.

Example

See the notes at the beginning of this chapter or section for information on using printf() or scanf() (and other functions reading and writing the stdin or stdout streams) in the example code.

#include <math.h>
#include <stdio.h>
#include <errno.h>

int main(void)
{
  double x, y;
  long int power;

  errno = 0;
  x = 13.45;
  power = 8;
  y = scalbln(x, power);
  if (errno)
    perror("Error");
  printf("FLT_RADIX raised to the power %ld, times %f is %f\n", power, x, y);
}

Example Output

FLT_RADIX raised to the power 8, times 13.450000 is 3443.200000