1 文本格式
using System;
namespace Legalsoft.Truffer
{
/// <summary>
/// 有理函数插值和外推
/// Rational Function Interpolation and Extrapolation
/// Given a value x, and using pointers to data xx and yy, this routine returns
/// an interpolated value y, and stores an error estimate dy. The returned value
/// is obtained by mm-point polynomial interpolation on the subrange
/// xx[jl..jl + mm - 1].
/// </summary>
public class Rational_interp : Base_interp
{
private double dy { get; set; }
public Rational_interp(double[] xv, double[] yv, int m) : base(xv, yv[0], m)
{
this.dy = 0.0;
}
/// <summary>
/// Given a value x, and using pointers to data xx and yy, this routine returns
/// an interpolated value y, and stores an error estimate dy. The returned
/// value is obtained by mm-point diagonal rational function interpolation on
/// the subrange xx[jl..jl + mm - 1].
/// </summary>
/// <param name="jl"></param>
/// <param name="x"></param>
/// <returns></returns>
/// <exception cref="Exception"></exception>
public override double rawinterp(int jl, double x)
{
const double TINY = 1.0e-99;
int ns = 0;
double[] c = new double[mm];
double[] d = new double[mm];
double hh = Math.Abs(x - xx[jl + 0]);
for (int i = 0; i < mm; i++)
{
double h = Math.Abs(x - xx[jl + i]);
//if (h == 0.0)
if (Math.Abs(h) <= float.Epsilon)
{
dy = 0.0;
return yy[jl + i];
}
else if (h < hh)
{
ns = i;
hh = h;
}
c[i] = yy[jl + i];
d[i] = yy[jl + i] + TINY;
}
double y = yy[jl + ns--];
for (int m = 1; m < mm; m++)
{
for (int i = 0; i < mm - m; i++)
{
double w = c[i + 1] - d[i];
double h = xx[jl + i + m] - x;
double t = (xx[jl + i] - x) * d[i] / h;
double dd = t - c[i + 1];
//if (dd == 0.0)
if (Math.Abs(dd) <= float.Epsilon)
{
throw new Exception("Error in routine ratint");
}
dd = w / dd;
d[i] = c[i + 1] * dd;
c[i] = t * dd;
}
y += (dy = (2 * (ns + 1) < (mm - m) ? c[ns + 1] : d[ns--]));
}
return y;
}
}
}
2 代码格式
cs
using System;
namespace Legalsoft.Truffer
{
/// <summary>
/// 有理函数插值和外推
/// Rational Function Interpolation and Extrapolation
/// Given a value x, and using pointers to data xx and yy, this routine returns
/// an interpolated value y, and stores an error estimate dy. The returned value
/// is obtained by mm-point polynomial interpolation on the subrange
/// xx[jl..jl + mm - 1].
/// </summary>
public class Rational_interp : Base_interp
{
private double dy { get; set; }
public Rational_interp(double[] xv, double[] yv, int m) : base(xv, yv[0], m)
{
this.dy = 0.0;
}
/// <summary>
/// Given a value x, and using pointers to data xx and yy, this routine returns
/// an interpolated value y, and stores an error estimate dy. The returned
/// value is obtained by mm-point diagonal rational function interpolation on
/// the subrange xx[jl..jl + mm - 1].
/// </summary>
/// <param name="jl"></param>
/// <param name="x"></param>
/// <returns></returns>
/// <exception cref="Exception"></exception>
public override double rawinterp(int jl, double x)
{
const double TINY = 1.0e-99;
int ns = 0;
double[] c = new double[mm];
double[] d = new double[mm];
double hh = Math.Abs(x - xx[jl + 0]);
for (int i = 0; i < mm; i++)
{
double h = Math.Abs(x - xx[jl + i]);
//if (h == 0.0)
if (Math.Abs(h) <= float.Epsilon)
{
dy = 0.0;
return yy[jl + i];
}
else if (h < hh)
{
ns = i;
hh = h;
}
c[i] = yy[jl + i];
d[i] = yy[jl + i] + TINY;
}
double y = yy[jl + ns--];
for (int m = 1; m < mm; m++)
{
for (int i = 0; i < mm - m; i++)
{
double w = c[i + 1] - d[i];
double h = xx[jl + i + m] - x;
double t = (xx[jl + i] - x) * d[i] / h;
double dd = t - c[i + 1];
//if (dd == 0.0)
if (Math.Abs(dd) <= float.Epsilon)
{
throw new Exception("Error in routine ratint");
}
dd = w / dd;
d[i] = c[i + 1] * dd;
c[i] = t * dd;
}
y += (dy = (2 * (ns + 1) < (mm - m) ? c[ns + 1] : d[ns--]));
}
return y;
}
}
}