- private double filter_coeff(double dist, double width) {
- double ratio = dist / (width / 2);
+ private static double i0(double x) {
+ double ds = 1, d = 0, s = 0;
+
+ do {
+ d += 2;
+ ds = ds * (x * x) / (d * d);
+ s += ds;
+ } while (ds - 0.2e-8 * s > 0);
+ return s;
+ }
+
+ private static double kaiser(double n, double m, double beta) {
+ double alpha = m / 2;
+ double t = (n - alpha) / alpha;