//, ref double[] D, ref double[] T)///Add 'D' term, for distance traveled laterally before exit. One number for each direction.
public static Complex[][] Transfer_Matrix_Explicit_Alpha(bool freq_log, bool Rigid_Backed, int sample_Freq, double c_sound, List<ABS_Layer> LayerList, ref double[] frequency, ref Complex[] anglesdeg)
{
if (freq_log)
{
//3rd octave band frequencies...
List<double> freq = new List<double>();
double f = 15.625;
int ct = 1;
while (f < sample_Freq / 2)
{
ct++;
f = 15.625 * Math.Pow(2, ct / 3);
freq.Add(f);
}
frequency = freq.ToArray();
}
else
{
//Linear frequency scale
frequency = new double[4096];
double step = (sample_Freq / 2) / 4096;
for (int i = 0; i < frequency.Length; i++) frequency[i] = (i + .5) * step;
}
anglesdeg = new Complex[(int)(180 / 5)];
double[] Angle = new double[anglesdeg.Length];
Complex[][] sintheta_inc = new Complex[36][];
Complex[][][] Angle_Inc = new Complex[LayerList.Count][][];
Complex[] K_Air = AbsorptionModels.Operations.Air_Wavenumber(c_sound, frequency);
Complex[] Zc_Air = AbsorptionModels.Operations.Air_CharImpedance(1.2, c_sound, frequency);
for (double a = 2.5, i = 0; a <= 180; a += 5, i++)
{
sintheta_inc[(int)i] = new Complex[frequency.Length];
anglesdeg[(int)i] = 90 - a;
if (a <= 90) Angle[(int)i] = (90 - a) * Utilities.Numerics.Pi_180;
sintheta_inc[(int)i][0] = Complex.Sin(a <= 90 ? Angle[(int)i] : Angle[36 - (int)i]);
for (int j = 1; j < sintheta_inc[(int)i].Length; j++) sintheta_inc[(int)i][j] = sintheta_inc[(int)i][0];
}
SparseMatrix[][][] T = new SparseMatrix[LayerList.Count][][];
for (int a = 0; a < anglesdeg.Length; a++)
{
//sintheta_trans[i][j] = K0[j] * sintheta_inc[i][j] / K[j];
//Kxi[i][j] = Complex.Sqrt(K[j] * K[j] * (1 - sintheta_trans[i][j] * sintheta_trans[i][j]));
}
for (int i = LayerList.Count - 1; i >= 0; i--)
{
ABS_Layer Layer_i = (LayerList[i] as ABS_Layer);
T[i] = new SparseMatrix[anglesdeg.Length][];
for(int a = 0; a < anglesdeg.Length; a++)
{
T[i][a] = new SparseMatrix[4096];
double sintheta = Math.Sin(Angle[a]);
switch (Layer_i.T)
{
case ABS_Layer.LayerType.AirSpace:
for(int f = 0; f < 4096; f++)
{
Complex Ksintheta = K_Air[f] * sintheta;
T[i][a][f] = Explicit_TMM.FluidMatrix(Layer_i.depth * 1000, Complex.Sqrt(K_Air[f] * K_Air[f] - Ksintheta * Ksintheta), frequency[f], 1.2);
}
break;
case ABS_Layer.LayerType.PorousDB:
Complex[] Kdb = Equivalent_Fluids.DelaneyBazley_WNumber(1.2, c_sound, Layer_i.Flow_Resist, frequency);
for(int f = 0; f < 4096; f++)
{
Complex Ksintheta = K_Air[f] * sintheta;
T[i][a][f] = Explicit_TMM.FluidMatrix(Layer_i.depth, Complex.Sqrt(Kdb[f] * Kdb[f] - Ksintheta * Ksintheta), frequency[f], 1.2);
}
break;
case ABS_Layer.LayerType.PorousCA:
Complex[] Kca = Equivalent_Fluids.DBAllardChampoux_WNumber(1.2, c_sound, Layer_i.Flow_Resist, frequency);
for(int f = 0; f < 4096; f++)
{
Complex Ksintheta = K_Air[f] * sintheta;
T[i][a][f] = Explicit_TMM.FluidMatrix(Layer_i.depth, Complex.Sqrt(Kca[f] * Kca[f] - Ksintheta * Ksintheta), frequency[f], 1.2);
}
break;
case ABS_Layer.LayerType.PorousM:
Complex[] Km = Equivalent_Fluids.DB_Miki_WNumber(1.2, c_sound, Layer_i.Flow_Resist, frequency);
for(int f = 0; f < 4096; f++)
{
//Complex Ksintheta = K_Air[f] * sintheta;
T[i][a][f] = Explicit_TMM.FluidMatrix(Layer_i.depth, Complex.Sqrt(Km[f] * Km[f] * (1 - sintheta * sintheta)), frequency[f], 1.2);
}
break;
//case ABS_Layer.LayerType.Perforated_Modal:
//case ABS_Layer.LayerType.Slotted_Modal:
//case ABS_Layer.LayerType.CircularPerforations:
//case ABS_Layer.LayerType.SquarePerforations:
//case ABS_Layer.LayerType.Slots:
//case ABS_Layer.LayerType.MicroPerforated:
//case ABS_Layer.LayerType.Microslit:
default:
throw new Exception("Unknown Layer Type");
}
}
}
SparseMatrix[] I = new SparseMatrix[LayerList.Count];
SparseMatrix[] J = new SparseMatrix[LayerList.Count];
//SparseMatrix Yterm;
//if ((int)LayerList[0].T <= 10)
//{
// //Fluid Layer
// Yterm = Explicit_TMM.RigidTerminationF();
//}
//else if ((int)LayerList[0].T == 15 || (int)LayerList[0].T == 16)
//{
// //Biot Porous absorbers
// Yterm = Explicit_TMM.RigidTerminationP();
//}
//else
//{
// //Solid Layer
// Yterm = Explicit_TMM.RigidTerminationS();
//}
//Get Interface Matrices
for (int i = 0; i < LayerList.Count; i++)
{
if (i == LayerList.Count - 1)
{
if ((int)LayerList[i].T <= 10)
{
//Fluid Layer
I[i] = MathNet.Numerics.LinearAlgebra.Complex.SparseMatrix.CreateIdentity(2);
J[i] = MathNet.Numerics.LinearAlgebra.Complex.SparseMatrix.CreateIdentity(2);
}
else if ((int)LayerList[i].T == 15 || (int)LayerList[i].T == 16)
{
//Biot Porous absorbers
I[i] = Explicit_TMM.Interfacepf_Porous(LayerList[i].porosity);
J[i] = Explicit_TMM.Interfacepf_Fluid(LayerList[i].porosity);
}
else
{
//Solid Layer
I[i] = Explicit_TMM.InterfaceSF_Solid();
J[i] = Explicit_TMM.InterfaceSF_Fluid();
}
continue;
}
if ((int)LayerList[i].T <= 10)
{
//Fluid Layer
if ((int)LayerList[i + 1].T <= 10)
{
//Fluid Layer
I[i] = MathNet.Numerics.LinearAlgebra.Complex.SparseMatrix.CreateIdentity(2);
J[i] = MathNet.Numerics.LinearAlgebra.Complex.SparseMatrix.CreateIdentity(2);
}
else if ((int)LayerList[i + 1].T == 15 || (int)LayerList[i + 1].T == 16)
{
//Biot Porous absorbers
I[i] = Explicit_TMM.Interfacepf_Fluid(LayerList[i + 1].porosity) as SparseMatrix;
J[i] = Explicit_TMM.Interfacepf_Porous(LayerList[i + 1].porosity);
}
else
{
//Solid Layer
I[i] = SparseMatrix.CreateIdentity(4);
J[i] = SparseMatrix.CreateIdentity(4);
}
}
else if ((int)LayerList[i].T == 15 || (int)LayerList[i + 1].T == 16)
{
//Biot Porous absorbers
if ((int)LayerList[i + 1].T <= 10)
{
//Fluid Layer
I[i] = Explicit_TMM.Interfacepf_Porous(LayerList[i].porosity);
J[i] = Explicit_TMM.Interfacepf_Fluid(LayerList[i].porosity);
}
else if ((int)LayerList[i + 1].T == 15 || (int)LayerList[i + 1].T == 16)
{
//Biot Porous absorbers
I[i] = Explicit_TMM.InterfacePP(LayerList[i].porosity, LayerList[i + 1].porosity);//TODO: Check that we have the right porosities in the right places...
J[i] = SparseMatrix.CreateIdentity(6);
}
else
{
//Solid Layer
I[i] = Explicit_TMM.Interfacesp_Porous();
J[i] = Explicit_TMM.Interfacesp_Solid();
}
}
else
{
//Solid Layer
if ((int)LayerList[i + 1].T <= 10)
{
//Fluid Layer
I[i] = Explicit_TMM.InterfaceSF_Solid();
J[i] = Explicit_TMM.InterfaceSF_Fluid();
}
else if ((int)LayerList[i + 1].T == 15 || (int)LayerList[i + 1].T == 16)
{
//Biot Porous absorbers
I[i] = Explicit_TMM.Interfacesp_Solid();
J[i] = Explicit_TMM.Interfacesp_Porous();
}
else
{
//Solid Layer
I[i] = Explicit_TMM.InterfaceSF_Fluid() as SparseMatrix;
J[i] = Explicit_TMM.InterfaceSF_Solid();
}
}
}
//List<SparseMatrix[][]> T = Layer(LayerList.Count - 1, LayerList, K_Air, sintheta_inc, K_Air, c_sound, frequency);
Complex[][] Z = new Complex[sintheta_inc.Length][];
for (int a = 0; a < sintheta_inc.Length; a++)
{
Z[a] = new Complex[sintheta_inc[a].Length];
for(int f = 0; f < sintheta_inc[a].Length; f++)
{
SparseMatrix V;
if (T.First()[a][f].RowCount == 2)
{
V = new SparseMatrix(2, 1);
V[0, 0] = 1;
}
else if (T.First()[a][f].RowCount == 4)
{
V = new SparseMatrix(4, 1);
V[0, 0] = 1;
V[1, 0] = 1;
}
else
{
V = new SparseMatrix(6, 1);
V[0, 0] = 1;
V[1, 0] = 1;
V[2, 0] = 1;
}
for (int i = 0; i < T.Length; i++)
{
V = -((J[i] * T[i][a][f]) * I[i].Inverse() as SparseMatrix) * V;
//V = T[i][a][f] * V;
}
V = -(J.Last() * I.Last().Inverse() as SparseMatrix) * V;
Z[a][f] = V[0, 0] * 100000 / V[1, 0];
}
}
return Z;
}