/// <summary>
/// 双线性插值
/// p00 ------------- p01
/// | |
/// p10 ------------- p11
///
/// TODO: handle boundary.
/// </summary>
/// <param name="f">二维图</param>
/// <param name="x">x</param>
/// <param name="y">y</param>
/// <param name="method"></param>
/// <returns></returns>
public static NcvVector interp2(double[] f, int cols, int rows, NcvVector x, NcvVector y, string method)
{
int n = x.n;
NcvVector vf = new NcvVector(n);
if (method.Equals("*linear", StringComparison.OrdinalIgnoreCase))
{
for (int k = 0; k < n; k++)
{
int p00Y = (int)Math.Floor(y[k]);
int p00X = (int)Math.Floor(x[k]);
int p01Y = (int)Math.Floor(y[k]);
int p01X = (int)Math.Ceiling(x[k]);
int p10Y = (int)Math.Ceiling(y[k]);
int p10X = (int)Math.Floor(x[k]);
int p11Y = (int)Math.Ceiling(y[k]);
int p11X = (int)Math.Ceiling(x[k]);
double a = y[k] - p00Y;
double b = x[k] - p00X;
double f00 = f[p00X * rows + p00Y];
double f01 = f[p01X * rows + p01Y];
double f10 = f[p10X * rows + p10Y];
double f11 = f[p11X * rows + p11Y];
double g = b * (a * f11 + (1 - a) * f01) + (1 - b) * (a * f01 + (1 - a) * f00);
//int i = round(x[k]) * m_Rows + round(y[k]);
vf[k] = g;
}
}
return(vf);
}
public static void DrawContour(Bitmap bmp, NcvVector x, NcvVector y)
{
List <DoublePoint> contour = new List <DoublePoint>();
for (int i = 0; i < x.n; i++)
{
contour.Add(new DoublePoint(x[i], y[i]));
}
DrawContour(bmp, contour);
}
public static NcvVector DotProduct(NcvVector v1, NcvVector v2)
{
NcvVector v3 = new NcvVector(v1.n);
for (int i = 0; i < v1.n; i++)
{
v3[i] = v1[i] * v2[i];
}
return(v3);
}
public static NcvVector operator *(NcvVector v1, double s2)
{
NcvVector v3 = new NcvVector(v1.n);
for (int i = 0; i < v1.n; i++)
{
v3[i] = v1[i] * s2;
}
return(v3);
}
public static NcvVector operator -(NcvVector v1)
{
NcvVector v2 = new NcvVector(v1.n);
for (int i = 0; i < v1.n; i++)
{
v2[i] = -v1[i];
}
return(v2);
}
public static NcvVector Ones(int n)
{
NcvVector ones = new NcvVector(n);
for (int i = 0; i < ones.n; i++)
{
ones[i] = 1.0;
}
return(ones);
}
public static NcvVector Sqrt(NcvVector v1)
{
NcvVector v2 = new NcvVector(v1.n);
for (int i = 0; i < v1.n; i++)
{
v2[i] = Math.Sqrt(v1[i]);
}
return(v2);
}
public static NcvMatrix diag(NcvVector v)
{
int n = v.n;
NcvMatrix m = new NcvMatrix(n, n);
for (int i = 0; i < n; i++)
{
m[i, i] = v[i];
}
return(m);
}
public static NcvVector operator -(NcvVector v1, NcvVector v2)
{
NcvVector v3 = new NcvVector(v1.n);
// v3 <- v1 + v2
for (int i = 0; i < v1.n; i++)
{
v3[i] = v1[i] - v2[i];
}
return(v3);
}
public static NcvVector operator *(NcvMatrix m1, NcvVector v2)
{
NcvVector v3 = new NcvVector(v2.n);
for (int y = 0; y < m1.rows(); y++)
{
for (int x = 0; x < m1.cols(); x++)
{
v3[y] += m1[x, y] * v2[y];
}
}
return(v3);
}
public static NcvVector cat(NcvVector v1, NcvVector v2)
{
NcvVector v3 = new NcvVector(v1.n + v2.n);
for (int i = 0; i < v1.n; i++)
{
v3[i] = v1[i];
}
for (int j = 0; j < v2.n; j++)
{
v3[v1.n + j] = v2[j];
}
return(v3);
}
public NcvVector sub(int startIndex, int length)
{
if (startIndex + length > this.n)
{
throw new ArgumentOutOfRangeException();
}
NcvVector v = new NcvVector(length);
for (int i = 0; i < length; i++)
{
v[i] = this[startIndex + i];
}
return(v);
}
public static NcvMatrix diag(NcvVector v, int k)
{
int n = v.n;
int order = n + Math.Abs(k);
NcvMatrix m = new NcvMatrix(order, order);
for (int i = 0; i < n; i++)
{
if (k <= 0)
{
m[i, i - k] = v[i];
}
else
{
m[i + k, i] = v[i];
}
}
return(m);
}
public static NcvVector interp1(NcvVector x, NcvVector Y, NcvVector xi)
{
return(new NcvVector(interp1(x.Data, Y.Data, xi.Data)));
}