/// <summary>
/// Returns a list of 3d POINTS. Uses cubic spline to interpolate.
/// </summary>
/// <param name="NumberOfPoints"></param>
/// <returns></returns>
public List <Point3D> Get3DPoints(int NumberOfPoints)
{
List <Point3D> interpolatedpoints = new List <Point3D>();
CubicSplineInterpolation spline = new CubicSplineInterpolation();
List <double> xcoors = new List <double>();
List <double> zcoors = new List <double>();
for (int i = 0; i < _xsec.Points.Count(); i++)
{
xcoors.Add(_xsec.Points[i].X);
zcoors.Add(_xsec.Points[i].Z);
}
spline.Initialize(xcoors, zcoors);
double xOffset = _xsec.LowestPoint.X;
double dx = (xcoors.Last() - xcoors.First()) / NumberOfPoints;
for (int i = 0; i < NumberOfPoints; i++)
{
double x = xcoors.First() + i * dx;
double z = spline.Interpolate(x);
interpolatedpoints.Add(new Point3D(MidStreamLocation.X - UnityVector.Y * (x - xOffset), MidStreamLocation.Y + UnityVector.X * (x - xOffset), z));
}
return(interpolatedpoints);
}
/// <summary>
/// Interpolation of the interface points onto the equidistant Fourier points
/// </summary>
protected void InterpolateOntoFourierPoints(MultidimensionalArray interP, double[] samplP)
{
int numP = interP.Lengths[0];
// set interpolation data
double[] independentVal = new double[numP + 2];
double[] dependentVal = new double[numP + 2];
for (int sp = 1; sp <= numP; sp++)
{
independentVal[sp] = interP[sp - 1, 0];
dependentVal[sp] = interP[sp - 1, 1];
}
// extend the interpolation data for sample points at the boundary of the domain
independentVal[0] = interP[numP - 1, 0] - DomainSize;
dependentVal[0] = interP[numP - 1, 1];
independentVal[numP + 1] = interP[0, 0] + DomainSize;
dependentVal[numP + 1] = interP[0, 1];
switch (this.InterpolationType)
{
case Interpolationtype.LinearSplineInterpolation:
LinearSplineInterpolation LinSpline = new LinearSplineInterpolation();
LinSpline.Initialize(independentVal, dependentVal);
for (int sp = 0; sp < numFp; sp++)
{
samplP[sp] = LinSpline.Interpolate(FourierP[sp]);
//invDFT_coeff[sp] = (Complex)samplP[sp];
}
break;
case Interpolationtype.CubicSplineInterpolation:
CubicSplineInterpolation CubSpline = new CubicSplineInterpolation();
CubSpline.Initialize(independentVal, dependentVal);
for (int sp = 0; sp < numFp; sp++)
{
samplP[sp] = CubSpline.Interpolate(FourierP[sp]);
//invDFT_coeff[sp] = (Complex)samplP[sp];
}
break;
default:
throw new NotImplementedException();
}
}
public void TestClampedCubicSplineInterpolation()
{
Random r = new Random(Environment.TickCount);
TearDown();
var interpolation = new CubicSplineInterpolation();
interpolation.Initialize(_times, _rates);
for (int i = 0; i < 10; ++i)
{
double time = (i + r.Next(-10000, 10000) / 10000);
double interpRate = interpolation.ValueAt(time, true);
Debug.WriteLine($"interpolatedRate : {interpRate} Time: {time}");
}
}
/// <summary>
/// Interpolation of no equidistant sample point onto equidistant Fourier points
/// </summary>
public static void InterpolateOntoFourierPoints(MultidimensionalArray samplP, double DomainSize, double[] samplFp)
{
int numSp = samplP.Lengths[0];
// set interpolation data (delete multiple independent values)
ArrayList independentList = new ArrayList();
ArrayList dependentList = new ArrayList();
for (int sp = 0; sp < numSp; sp++)
{
if (independentList.Contains(samplP[sp, 0]) == false)
{
independentList.Add(samplP[sp, 0]);
dependentList.Add(samplP[sp, 1]);
}
}
// extend the interpolation data for sample points at the boundary of the domain
independentList.Insert(0, samplP[numSp - 1, 0] - DomainSize);
independentList.Insert(independentList.Count, samplP[0, 0] + DomainSize);
dependentList.Insert(0, samplP[numSp - 1, 1]);
dependentList.Insert(dependentList.Count, samplP[0, 1]);
double[] independentVal = (double[])independentList.ToArray(typeof(double));
double[] dependentVal = (double[])dependentList.ToArray(typeof(double));
// set Fourier points
int numSFp = samplFp.Length;
double[] FourierP = new double[numSFp];
for (int i = 0; i < numSFp; i++)
{
FourierP[i] = (DomainSize / numSFp) * i;
}
switch (InterpolationType)
{
case Interpolationtype.LinearSplineInterpolation:
LinearSplineInterpolation LinSpline = new LinearSplineInterpolation();
LinSpline.Initialize(independentVal, dependentVal);
for (int Fp = 0; Fp < numSFp; Fp++)
{
samplFp[Fp] = LinSpline.Interpolate(FourierP[Fp]);
}
break;
case Interpolationtype.CubicSplineInterpolation:
CubicSplineInterpolation CubSpline = new CubicSplineInterpolation();
CubSpline.Initialize(independentVal, dependentVal);
for (int Fp = 0; Fp < numSFp; Fp++)
{
samplFp[Fp] = CubSpline.Interpolate(FourierP[Fp]);
}
break;
default:
throw new NotImplementedException();
}
}