func NewFFTUpdater(qin, qout *Quant) *FFTUpdater {
u := new(FFTUpdater)
u.in = qin
u.out = qout
meshSize := engine.GridSize()
u.win = gpu.NewArray(1, meshSize)
u.win.CopyFromHost(genWindow(meshSize))
u.q = gpu.NewArray(qin.NComp(), meshSize)
u.norm = 1.0 / float64(gpu.FFTNormLogic(meshSize))
u.plan = gpu.NewDefaultFFT(meshSize, meshSize)
engine.Depends(qout.Name(), qin.Name())
return u
}
//// Loads a sub-kernel at position pos in the 3x3 global kernel matrix.
//// The symmetry and real/imaginary/complex properties are taken into account to reduce storage.
func (plan *MaxwellPlan) LoadKernel(kernel *host.Array, matsymm int, realness int) {
// for i := range kernel.Array {
// Debug("kernel", TensorIndexStr[i], ":", kernel.Array[i], "\n\n\n")
// }
//Assert(kernel.NComp() == 9) // full tensor
if kernel.NComp() > 3 {
testedsymm := MatrixSymmetry(kernel)
Debug("matsymm", testedsymm)
// TODO: re-enable!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
//Assert(matsymm == testedsymm)
}
Assert(matsymm == SYMMETRIC || matsymm == ANTISYMMETRIC || matsymm == NOSYMMETRY || matsymm == DIAGONAL)
//if FFT'd kernel is pure real or imag,
//store only relevant part and multiply by scaling later
scaling := [3]complex128{complex(1, 0), complex(0, 1), complex(0, 0)}[realness]
Debug("scaling=", scaling)
// FFT input on GPU
logic := plan.logicSize[:]
devIn := gpu.NewArray(1, logic)
defer devIn.Free()
// FFT output on GPU
devOut := gpu.NewArray(1, gpu.FFTOutputSize(logic))
defer devOut.Free()
fullFFTPlan := gpu.NewDefaultFFT(logic, logic)
defer fullFFTPlan.Free()
// Maximum of all elements gives idea of scale.
max := maxAbs(kernel.List)
// FFT all components
for k := 0; k < 9; k++ {
i, j := IdxToIJ(k) // fills diagonal first, then upper, then lower
// ignore off-diagonals of vector (would go out of bounds)
if k > ZZ && matsymm == DIAGONAL {
Debug("break", TensorIndexStr[k], "(off-diagonal)")
break
}
// elements of diagonal kernel are stored in one column
if matsymm == DIAGONAL {
i = 0
}
// clear data first
AssertMsg(plan.fftKern[i][j] == nil, "I'm afraid I can't let you overwrite that")
AssertMsg(plan.fftMul[i][j] == 0, "Likewise")
// auto-fill lower triangle if possible
if k > XY {
if matsymm == SYMMETRIC {
plan.fftKern[i][j] = plan.fftKern[j][i]
plan.fftMul[i][j] = plan.fftMul[j][i]
continue
}
if matsymm == ANTISYMMETRIC {
plan.fftKern[i][j] = plan.fftKern[j][i]
plan.fftMul[i][j] = -plan.fftMul[j][i]
continue
}
}
// ignore zeros
if k < kernel.NComp() && IsZero(kernel.Comp[k], max) {
Debug("kernel", TensorIndexStr[k], " == 0")
plan.fftKern[i][j] = gpu.NilArray(1, []int{plan.fftKernSize[X], plan.fftKernSize[Y], plan.fftKernSize[Z]})
continue
}
// calculate FFT of kernel elementx
Debug("use", TensorIndexStr[k])
devIn.CopyFromHost(kernel.Component(k))
fullFFTPlan.Forward(devIn, devOut)
hostOut := devOut.LocalCopy()
// extract real part of the kernel from the first quadrant (other parts are redundunt due to the symmetry properties)
hostFFTKern := extract(hostOut)
rescale(hostFFTKern, 1/float64(gpu.FFTNormLogic(logic)))
plan.fftKern[i][j] = gpu.NewArray(1, hostFFTKern.Size3D)
plan.fftKern[i][j].CopyFromHost(hostFFTKern)
plan.fftMul[i][j] = scaling
}
}