static void BDRksmooth(double *x, double *y, R_xlen_t n,
double *xp, double *yp, R_xlen_t np,
int kern, double bw)
{
R_xlen_t imin = 0;
double cutoff = 0.0, num, den, x0, w;
/* bandwidth is in units of half inter-quartile range. */
if(kern == 1) {bw *= 0.5; cutoff = bw;}
if(kern == 2) {bw *= 0.3706506; cutoff = 4*bw;}
while(x[imin] < xp[0] - cutoff && imin < n) imin++;
for(R_xlen_t j = 0; j < np; j++) {
num = den = 0.0;
x0 = xp[j];
for(R_xlen_t i = imin; i < n; i++) {
if(x[i] < x0 - cutoff) imin = i;
else {
if(x[i] > x0 + cutoff) break;
w = dokern(fabs(x[i] - x0)/bw, kern);
num += w*y[i];
den += w;
}
}
if(den > 0) yp[j] = num/den; else yp[j] = NA_REAL;
}
}
void BDRksmooth(double *x, double *y, int *n,
double *xp, double *yp, int *np,
int *kern, double *bandwidth)
{
int i, imin=0, j;
double cutoff=0.0, num, den, x0, w, bw=*bandwidth;
/* bandwidth is in units of half inter-quartile range. */
if(*kern == 1) {bw *= 0.5; cutoff = bw;}
if(*kern == 2) {bw *= 0.3706506; cutoff = 4*bw;}
while(x[imin] < xp[0] - cutoff && imin < *n) imin++;
for(j = 0; j < *np; j++) {
num = den = 0.0;
x0 = xp[j];
for(i = imin; i < *n; i++) {
if(x[i] < x0 - cutoff) imin = i;
else {
if(x[i] > x0 + cutoff) break;
w = dokern(fabs(x[i] - x0)/bw, *kern);
num += w*y[i];
den += w;
}
}
if(den > 0) yp[j] = num/den; else yp[j] = NA_REAL;
}
}
