56 lines
1.7 KiB
Java
56 lines
1.7 KiB
Java
import static java.lang.Math.*;
|
|
|
|
public class Test {
|
|
final static int N = 32;
|
|
final static int N2 = (N * (N - 1) / 2);
|
|
final static double STEP = 0.05;
|
|
|
|
static double[] xval = new double[N];
|
|
static double[] t_sin = new double[N];
|
|
static double[] t_cos = new double[N];
|
|
static double[] t_tan = new double[N];
|
|
|
|
static double[] r_sin = new double[N2];
|
|
static double[] r_cos = new double[N2];
|
|
static double[] r_tan = new double[N2];
|
|
|
|
static double rho(double[] x, double[] y, double[] r, int i, int n) {
|
|
if (n < 0)
|
|
return 0;
|
|
|
|
if (n == 0)
|
|
return y[i];
|
|
|
|
int idx = (N - 1 - n) * (N - n) / 2 + i;
|
|
if (r[idx] != r[idx])
|
|
r[idx] = (x[i] - x[i + n])
|
|
/ (rho(x, y, r, i, n - 1) - rho(x, y, r, i + 1, n - 1))
|
|
+ rho(x, y, r, i + 1, n - 2);
|
|
|
|
return r[idx];
|
|
}
|
|
|
|
static double thiele(double[] x, double[] y, double[] r, double xin, int n) {
|
|
if (n > N - 1)
|
|
return 1;
|
|
return rho(x, y, r, 0, n) - rho(x, y, r, 0, n - 2)
|
|
+ (xin - x[n]) / thiele(x, y, r, xin, n + 1);
|
|
}
|
|
|
|
public static void main(String[] args) {
|
|
for (int i = 0; i < N; i++) {
|
|
xval[i] = i * STEP;
|
|
t_sin[i] = sin(xval[i]);
|
|
t_cos[i] = cos(xval[i]);
|
|
t_tan[i] = t_sin[i] / t_cos[i];
|
|
}
|
|
|
|
for (int i = 0; i < N2; i++)
|
|
r_sin[i] = r_cos[i] = r_tan[i] = Double.NaN;
|
|
|
|
System.out.printf("%16.14f%n", 6 * thiele(t_sin, xval, r_sin, 0.5, 0));
|
|
System.out.printf("%16.14f%n", 3 * thiele(t_cos, xval, r_cos, 0.5, 0));
|
|
System.out.printf("%16.14f%n", 4 * thiele(t_tan, xval, r_tan, 1.0, 0));
|
|
}
|
|
}
|