/*******************************************************************
*  FIR - This C function performs FIR filtering operation as:
*          ntap-1
*    y(n) = sum  wi * x(n-i)
*           i=0
*******************************************************************/
float fir(x, w, ntap)

float *x, *w;                  // signal & coefficient pointers
int ntap;                      // length of filter
{
  float yn;                    // output of FIR filter
  int i;                       // index
  yn = 0.0;                    // y(n) = 0.
  for (i=0; i<ntap; ++i)
  {
    yn += w[i]*x[i];           // FIR filtering of x(n) to get y(n)
  }
  return(yn);                  // return y(n) to main function
}