Floating-point Summation

Listing 7: Kahan Summation

float fk_add(float * flt_arr)
{
  long i;
  float sum, correction, corrected_next_term, new_sum;

  sum = flt_arr[0];
  correction = 0.0;
  for (i = 1; i < ARR_SIZE; i++)
  {
    corrected_next_term = flt_arr[i] - correction;
    new_sum = sum + corrected_next_term;
    correction = (new_sum - sum) - corrected_next_term;
    sum = new_sum;
  }
  return sum;
}
/* End of File */