Esempio n. 1
0
// Detects matrix symmetry.
// returns NOSYMMETRY, SYMMETRIC, ANTISYMMETRIC
func MatrixSymmetry(matrix *host.Array) int {
	AssertMsg(matrix.NComp() == 9, "MatrixSymmetry NComp")
	symm := true
	asymm := true
	max := 1e-100
	for i := 0; i < 3; i++ {
		for j := 0; j < 3; j++ {
			scount := 0
			acount := 0
			total := 0
			idx1 := FullTensorIdx[i][j]
			idx2 := FullTensorIdx[j][i]
			comp1 := matrix.Comp[idx1]
			comp2 := matrix.Comp[idx2]
			for x := range comp1 {
				if math.Abs(float64(comp1[x])) > max {
					max = math.Abs(float64(comp1[x]))
				}
				total++
				if comp1[x] == comp2[x] {
					scount++
				}
				if comp1[x] != comp2[x] {
					//Debug(comp1[x], "!=", comp2[x])
					symm = false
					//if !asymm {
					//break
					//}
				}
				if comp1[x] == -comp2[x] {
					acount++
				}
				if comp1[x] != -comp2[x] {
					//Debug(comp1[x] ,"!= -", comp2[x])
					asymm = false
					//if !symm {
					//break
					//}
				}
			}
			Debug("max", max)
			Debug(i, j, "symm", scount, "asymm", acount, "(of", total, ")")
		}
	}
	if symm {
		return SYMMETRIC // also covers all zeros
	}
	if asymm {
		return ANTISYMMETRIC
	}
	return NOSYMMETRY
}
Esempio n. 2
0
// Convert mumax's internal ZYX convention to userspace XYZ.
func convertXYZ(arr *host.Array) *host.Array {
	s := arr.Size3D
	n := arr.NComp()
	a := arr.Array
	transp := host.NewArray(n, []int{s[Z], s[Y], s[X]})
	t := transp.Array
	for c := 0; c < n; c++ {
		for i := 0; i < s[X]; i++ {
			for j := 0; j < s[Y]; j++ {
				for k := 0; k < s[Z]; k++ {
					t[(n-1)-c][k][j][i] = a[c][i][j][k]
				}
			}
		}
	}
	runtime.GC() // a LOT of garbage has been made
	return transp
}
Esempio n. 3
0
// Returns a new host array of size size2, re-sized from the input array by nearest-neighbor interpolation.
func Resample(in *host.Array, size2 []int) *host.Array {
	Assert(len(size2) == 3)

	out := host.NewArray(in.NComp(), size2)
	out_a := out.Array
	in_a := in.Array
	size1 := in.Size3D
	for c := range out_a {
		for i := range out_a[c] {
			i1 := (i * size1[X]) / size2[X]
			for j := range out_a[0][i] {
				j1 := (j * size1[Y]) / size2[Y]
				for k := range out_a[0][i][j] {
					k1 := (k * size1[Z]) / size2[Z]
					out_a[c][i][j][k] = in_a[c][i1][j1][k1]
				}
			}
		}
	}
	return out
}
Esempio n. 4
0
// Extract real or imaginary parts, copy them from src to dst.
// In the meanwhile, check if the other parts are nearly zero
// and scale the kernel to compensate for unnormalized FFTs.
// real_imag = 0: real parts
// real_imag = 1: imag parts
func extract(src *host.Array) *host.Array {

	sx := src.Size3D[X]/2 + 1 // antisymmetric
	sy := src.Size3D[Y]/2 + 1 // antisymmetric
	sz := src.Size3D[Z] / 2   // only real parts should be stored, the value of the imaginary part should stay below the zero threshould
	dst := host.NewArray(src.NComp(), []int{sx, sy, sz})

	dstArray := dst.Array
	srcArray := src.Array

	// Normally, the FFT'ed kernel is purely real because of symmetry,
	// so we only store the real parts...
	maxImg := float64(0.)
	maxReal := float64(0.)
	for c := range dstArray {
		for k := range dstArray[c] {
			for j := range dstArray[c][k] {
				for i := range dstArray[c][k][j] {
					dstArray[c][k][j][i] = srcArray[c][k][j][2*i]
					if Abs32(srcArray[c][k][j][2*i+1]) > maxImg {
						maxImg = Abs32(srcArray[c][k][j][2*i+1])
					}
					if Abs32(srcArray[c][k][j][2*i+0]) > maxReal {
						maxReal = Abs32(srcArray[c][k][j][2*i+0])
					}
				}
			}
		}
	}
	// ...however, we check that the imaginary parts are nearly zero,
	// just to be sure we did not make a mistake during kernel creation.
	Debug("FFT Kernel max real part", 0, ":", maxReal)
	Debug("FFT Kernel max imag part", 1, ":", maxImg)
	Debug("FFT Kernel max imag/real part=", maxImg/maxReal)
	if maxImg/maxReal > 1e-12 { // TODO: is this reasonable?
		panic(BugF("FFT Kernel max bad/good part=", maxImg/maxReal))
	}
	return dst
}
Esempio n. 5
0
//// 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
	}

}