Power Function

The following functions are equivalent to the function gsl_pow_int (see section Small integer powers) with an error estimate. These functions are declared in the header file `gsl_sf_pow_int.h'.

Function: double gsl_sf_pow_int (double x, int n)

Function: int gsl_sf_pow_int_e (double x, int n, gsl_sf_result * result)

These routines compute the power @math{x^n} for integer n. The power is computed using the minimum number of multiplications. For example, @math{x^8} is computed as @math{((x^2)^2)^2}, requiring only 3 multiplications. For reasons of efficiency, these functions do not check for overflow or underflow conditions.

#include <gsl/gsl_sf_pow_int.h>
/* compute 3.0**12 */
double y = gsl_sf_pow_int(3.0, 12);