public static Image GetAnisotropicFSC(Image volume1,
Image volume2,
Image mask,
float pixelsize,
float threshold,
int healpixOrder,
float scaleToGlobalShell)
{
float MaskFraction = mask.GetHostContinuousCopy().Sum() / mask.ElementsReal;
Image Masked1 = volume1.GetCopyGPU();
volume1.FreeDevice();
Masked1.Multiply(mask);
Image Volume1FT = Masked1.AsFFT(true);
Masked1.Dispose();
Image Masked2 = volume2.GetCopyGPU();
Masked2.Multiply(mask);
volume2.FreeDevice();
Image Volume2FT = Masked2.AsFFT(true);
Masked2.Dispose();
mask.FreeDevice();
float2[] Angles = Helper.GetHealpixRotTilt(healpixOrder, "C1", 91f);
float3[] Directions = Angles.Select(a => Matrix3.Euler(a.X * Helper.ToRad, a.Y * Helper.ToRad, 0).Transposed() * float3.UnitZ).ToArray();
float AngleSpacing = (float)(60.0 / Math.Pow(2, Math.Min(2, healpixOrder)));
float[] ConeShells = new float[Directions.Length];
CPU.ConicalFSC(Volume1FT.GetHostContinuousCopy(),
Volume2FT.GetHostContinuousCopy(),
volume1.Dims,
Helper.ToInterleaved(Directions),
Directions.Length,
AngleSpacing,
10,
threshold,
MaskFraction,
ConeShells);
Volume1FT.Dispose();
Volume2FT.Dispose();
float MeanShell = MathHelper.MeanWeighted(ConeShells, MathHelper.Mult(ConeShells, ConeShells));
ConeShells = ConeShells.Select(v => v / MeanShell * scaleToGlobalShell).ToArray();
int NRot = (int)Math.Ceiling(360f / AngleSpacing * 2);
float StepRot = 360f / NRot;
int NTilt = (int)Math.Ceiling(90f / AngleSpacing * 2);
float StepTilt = 90f / NTilt;
float[] PolarValues = new float[NRot * NTilt];
for (int t = 0; t < NTilt; t++)
{
float Tilt = t * StepTilt;
for (int r = 0; r < NRot; r++)
{
float Rot = r * StepRot;
float3 Direction = Matrix3.Euler(Rot * Helper.ToRad, Tilt * Helper.ToRad, 0).Transposed() * float3.UnitZ;
float WeightedShell = 0;
float Weights = 0;
for (int d = 0; d < Directions.Length; d++)
{
float AngleDiff = (float)Math.Acos(Math.Min(1, Math.Abs(float3.Dot(Directions[d], Direction)))) * Helper.ToDeg;
float Weight = 1 - Math.Min(1, AngleDiff / AngleSpacing);
WeightedShell += ConeShells[d] * Weight;
Weights += Weight;
}
PolarValues[t * NRot + r] = volume1.Dims.X * pixelsize / (WeightedShell / Weights);
}
}
return(new Image(PolarValues, new int3(NRot, NTilt, 1)));
}
