/// <summary>
/// интерполяция
/// </summary>
/// <param name="?"></param>
public static void interpolation(Vector[] data,
double x,
double[] mt,
out double ys)
{
int i = 1;
double d, h1, p1, ra, ysa;
while (x > data[i].X)
i++;
int j = i - 1;
d = data[i].X - data[j].X;
h1 = x - data[j].X;
ra = data[i].X - x;
p1 = d * d / 6;
ys = (mt[j] * Math.Pow(ra, 3) + mt[i] * Math.Pow(h1, 3)) / 6 / d;
ysa = (data[j].Y - mt[j] * p1) * ra;
ysa = ysa + (data[i].Y - mt[i] * p1) * h1;
ys = ys + ysa / d;
}
/// <summary>
/// интерполяция кубическими сплайнами
/// </summary>
/// <param name="term"></param>
/// <param name="eject"></param>
/// <param name="num"></param>
/// <param name="m"></param>
/// <param name="nn"></param>
public static void interpolationCubicSplineMethod(Vector[] term,
Vector[] eject,
int num,
ref double[] m,
int nn)
{
double[] l = new double[nn];
double[] s = new double[nn];
double[] r = new double[nn];
double d = 0, e = 0, h1, p1, f5;
for (int h = 0; h < nn; h++)
{
l[h] = 0;
s[h] = 0;
r[h] = 0;
}
if (num == 1)
{
d = term[0].X - term[1].X;
e = (term[1].Y - term[0].Y) / d;
}
else if (num == 2)
{
d = eject[1].X - eject[0].X;
e = (eject[1].Y - eject[0].Y) / d;
}
for (int i = 1; i < nn - 1; i++)
{
h1 = d;
f5 = e;
if (num == 1)
{
d = term[i + 1].X - term[i].X;
e = (term[i + 1].Y - term[i].Y) / d;
}
else if (num == 2)
{
d = eject[i + 1].X - eject[i].X;
e = (eject[i + 1].Y - eject[i].Y) / d;
}
l[i] = d / (d + h1);
r[i] = 1 - l[i];
s[i] = 6 * (e - f5) / (h1 + d);
}
for (uint i = 1; i < nn - 1; i++)
{
p1 = 1 / (r[i] * l[i - 1] + 2);
l[i] = -l[i] * p1;
s[i] = (s[i] - r[i] * s[i - 1]) * p1;
}
m[nn - 1] = 0;
l[nn - 2] = s[nn - 2];
m[nn - 2] = l[nn - 2];
for (int i = nn - 3; i >= 0; i--)
{
l[i] = l[i] * l[i + 1] + s[i];
m[i] = l[i];
}
}