Golang Slice.Size方法代碼示例

func crop(f *data.Slice) {
	N := f.Size()
	// default ranges
	x1, x2 := 0, N[X]
	y1, y2 := 0, N[Y]
	z1, z2 := 0, N[Z]
	havework := false

	if *flag_cropz != "" {
		z1, z2 = parseRange(*flag_cropz, N[Z])
		havework = true
	}
	if *flag_cropy != "" {
		y1, y2 = parseRange(*flag_cropy, N[Y])
		havework = true
	}
	if *flag_cropx != "" {
		x1, x2 = parseRange(*flag_cropx, N[X])
		havework = true
	}

	if havework {
		*f = *data.Crop(f, x1, x2, y1, y2, z1, z2)
	}
}

// Writes data in OMF Binary 4 format
func writeOVF1Binary4(out io.Writer, array *data.Slice) (err error) {
	data := array.Tensors()
	gridsize := array.Size()

	var bytes []byte

	// OOMMF requires this number to be first to check the format
	var controlnumber float32 = OVF_CONTROL_NUMBER_4
	// Conversion form float32 [4]byte in big-endian
	// Inlined for performance, terabytes of data will pass here...
	bytes = (*[4]byte)(unsafe.Pointer(&controlnumber))[:]
	bytes[0], bytes[1], bytes[2], bytes[3] = bytes[3], bytes[2], bytes[1], bytes[0] // swap endianess
	_, err = out.Write(bytes)

	ncomp := array.NComp()
	for iz := 0; iz < gridsize[Z]; iz++ {
		for iy := 0; iy < gridsize[Y]; iy++ {
			for ix := 0; ix < gridsize[X]; ix++ {
				for c := 0; c < ncomp; c++ {
					// dirty conversion from float32 to [4]byte
					bytes = (*[4]byte)(unsafe.Pointer(&data[c][iz][iy][ix]))[:]
					bytes[0], bytes[1], bytes[2], bytes[3] = bytes[3], bytes[2], bytes[1], bytes[0]
					out.Write(bytes)
				}
			}
		}
	}
	return
}

// shift dst by shx cells (positive or negative) along X-axis.
// new edge value is clampL at left edge or clampR at right edge.
func ShiftX(dst, src *data.Slice, shiftX int, clampL, clampR float32) {
	util.Argument(dst.NComp() == 1 && src.NComp() == 1)
	util.Assert(dst.Len() == src.Len())
	N := dst.Size()
	cfg := make3DConf(N)
	k_shiftx_async(dst.DevPtr(0), src.DevPtr(0), N[X], N[Y], N[Z], shiftX, clampL, clampR, cfg)
}

func writeOVF2DataBinary4(out io.Writer, array *data.Slice) {

	//w.count(w.out.Write((*(*[1<<31 - 1]byte)(unsafe.Pointer(&list[0])))[0 : 4*len(list)])) // (shortcut)

	data := array.Tensors()
	size := array.Size()

	var bytes []byte

	// OOMMF requires this number to be first to check the format
	var controlnumber float32 = OVF_CONTROL_NUMBER_4
	bytes = (*[4]byte)(unsafe.Pointer(&controlnumber))[:]
	out.Write(bytes)

	ncomp := array.NComp()
	for iz := 0; iz < size[Z]; iz++ {
		for iy := 0; iy < size[Y]; iy++ {
			for ix := 0; ix < size[X]; ix++ {
				for c := 0; c < ncomp; c++ {
					bytes = (*[4]byte)(unsafe.Pointer(&data[c][iz][iy][ix]))[:]
					out.Write(bytes)
				}
			}
		}
	}
}

func (b *magnetization) SetArray(src *data.Slice) {
	if src.Size() != b.Mesh().Size() {
		src = data.Resample(src, b.Mesh().Size())
	}
	data.Copy(b.Buffer(), src)
	M.normalize()
}

func readOVF1DataBinary8(in io.Reader, t *data.Slice) {
	size := t.Size()
	data := t.Tensors()

	// OOMMF requires this number to be first to check the format
	var controlnumber float64
	// OVF 1.0 is network byte order (MSB)
	binary.Read(in, binary.BigEndian, &controlnumber)

	if controlnumber != OVF_CONTROL_NUMBER_8 {
		panic("invalid OVF1 control number: " + fmt.Sprint(controlnumber))
	}

	var tmp float64
	for iz := 0; iz < size[Z]; iz++ {
		for iy := 0; iy < size[Y]; iy++ {
			for ix := 0; ix < size[X]; ix++ {
				for c := 0; c < 3; c++ {
					err := binary.Read(in, binary.BigEndian, &tmp)
					if err != nil {
						panic(err)
					}
					data[c][iz][iy][ix] = float32(tmp)
				}
			}
		}
	}
}

// Write the slice to out in binary format. Add time stamp.
func Write(out io.Writer, s *data.Slice, info data.Meta) error {
	w := newWriter(out)

	// Writes the header.
	w.writeString(MAGIC)
	w.writeUInt64(uint64(s.NComp()))
	size := s.Size()
	w.writeUInt64(uint64(size[2])) // backwards compatible coordinates!
	w.writeUInt64(uint64(size[1]))
	w.writeUInt64(uint64(size[0]))
	cell := info.CellSize
	w.writeFloat64(cell[2])
	w.writeFloat64(cell[1])
	w.writeFloat64(cell[0])
	w.writeString(info.MeshUnit)
	w.writeFloat64(info.Time)
	w.writeString("s") // time unit
	w.writeString(info.Name)
	w.writeString(info.Unit)
	w.writeUInt64(4) // precission

	// return header write error before writing data
	if w.err != nil {
		return w.err
	}

	w.writeData(s)
	w.writeHash()
	return w.err
}

func writeVTKHeader(out io.Writer, q *data.Slice) (err error) {
	gridsize := q.Size()
	_, err = fmt.Fprintln(out, "<?xml version=\"1.0\"?>")
	_, err = fmt.Fprintln(out, "<VTKFile type=\"StructuredGrid\" version=\"0.1\" byte_order=\"LittleEndian\">")
	_, err = fmt.Fprintf(out, "\t<StructuredGrid WholeExtent=\"0 %d 0 %d 0 %d\">\n", gridsize[0]-1, gridsize[1]-1, gridsize[2]-1)
	_, err = fmt.Fprintf(out, "\t\t<Piece Extent=\"0 %d 0 %d 0 %d\">\n", gridsize[0]-1, gridsize[1]-1, gridsize[2]-1)
	return
}

// Calculate the demag field of m * vol * Bsat, store result in B.
// 	m:    magnetization normalized to unit length
// 	vol:  unitless mask used to scale m's length, may be nil
// 	Bsat: saturation magnetization in Tesla
// 	B:    resulting demag field, in Tesla
func (c *DemagConvolution) Exec(B, m, vol *data.Slice, Bsat LUTPtr, regions *Bytes) {
	util.Argument(B.Size() == c.inputSize && m.Size() == c.inputSize)
	if c.is2D() {
		c.exec2D(B, m, vol, Bsat, regions)
	} else {
		c.exec3D(B, m, vol, Bsat, regions)
	}
}

// Calculate the demag field of m * vol * Bsat, store result in B.
// 	m:    magnetization normalized to unit length
// 	vol:  unitless mask used to scale m's length, may be nil
// 	Bsat: saturation magnetization in Tesla
// 	B:    resulting demag field, in Tesla
func (c *DemagConvolution) Exec(B, m, vol *data.Slice, Msat MSlice) {
	util.Argument(B.Size() == c.inputSize && m.Size() == c.inputSize)
	if c.is2D() {
		c.exec2D(B, m, vol, Msat)
	} else {
		c.exec3D(B, m, vol, Msat)
	}
}

// average of slice over universe
func sAverageUniverse(s *data.Slice) []float64 {
	nCell := float64(prod(s.Size()))
	avg := make([]float64, s.NComp())
	for i := range avg {
		avg[i] = float64(cuda.Sum(s.Comp(i))) / nCell
		checkNaN1(avg[i])
	}
	return avg
}

func writeOVF2Header(out io.Writer, q *data.Slice, meta data.Meta) {
	gridsize := q.Size()
	cellsize := meta.CellSize

	fmt.Fprintln(out, "# OOMMF OVF 2.0")
	hdr(out, "Segment count", "1")
	hdr(out, "Begin", "Segment")
	hdr(out, "Begin", "Header")

	hdr(out, "Title", meta.Name)
	hdr(out, "meshtype", "rectangular")
	hdr(out, "meshunit", "m")

	hdr(out, "xmin", 0)
	hdr(out, "ymin", 0)
	hdr(out, "zmin", 0)

	hdr(out, "xmax", cellsize[X]*float64(gridsize[X]))
	hdr(out, "ymax", cellsize[Y]*float64(gridsize[Y]))
	hdr(out, "zmax", cellsize[Z]*float64(gridsize[Z]))

	name := meta.Name
	var labels []interface{}
	if q.NComp() == 1 {
		labels = []interface{}{name}
	} else {
		for i := 0; i < q.NComp(); i++ {
			labels = append(labels, name+"_"+string('x'+i))
		}
	}
	hdr(out, "valuedim", q.NComp())
	hdr(out, "valuelabels", labels...) // TODO
	unit := meta.Unit
	if unit == "" {
		unit = "1"
	}
	if q.NComp() == 1 {
		hdr(out, "valueunits", unit)
	} else {
		hdr(out, "valueunits", unit, unit, unit)
	}

	// We don't really have stages
	//fmt.Fprintln(out, "# Desc: Stage simulation time: ", meta.TimeStep, " s") // TODO
	hdr(out, "Desc", "Total simulation time: ", meta.Time, " s")

	hdr(out, "xbase", cellsize[X]/2)
	hdr(out, "ybase", cellsize[Y]/2)
	hdr(out, "zbase", cellsize[Z]/2)
	hdr(out, "xnodes", gridsize[X])
	hdr(out, "ynodes", gridsize[Y])
	hdr(out, "znodes", gridsize[Z])
	hdr(out, "xstepsize", cellsize[X])
	hdr(out, "ystepsize", cellsize[Y])
	hdr(out, "zstepsize", cellsize[Z])
	hdr(out, "End", "Header")
}

func shiftMag(m *data.Slice, dx int) {
	m2 := cuda.Buffer(1, m.Size())
	defer cuda.Recycle(m2)
	for c := 0; c < m.NComp(); c++ {
		comp := m.Comp(c)
		cuda.ShiftX(m2, comp, dx, float32(ShiftMagL[c]), float32(ShiftMagR[c]))
		data.Copy(comp, m2) // str0 ?
	}
}

// Set s to the toplogogical charge density s = m · (m/∂x ❌ ∂m/∂y)
// See topologicalcharge.cu
func SetTopologicalCharge(s *data.Slice, m *data.Slice, mesh *data.Mesh) {
	cellsize := mesh.CellSize()
	N := s.Size()
	util.Argument(m.Size() == N)
	cfg := make3DConf(N)
	icxcy := float32(1.0 / (cellsize[X] * cellsize[Y]))

	k_settopologicalcharge_async(s.DevPtr(X),
		m.DevPtr(X), m.DevPtr(Y), m.DevPtr(Z),
		icxcy, N[X], N[Y], N[Z], mesh.PBC_code(), cfg)
}

// Add effective field of Dzyaloshinskii-Moriya interaction to Beff (Tesla).
// According to Bagdanov and Röβler, PRL 87, 3, 2001. eq.8 (out-of-plane symmetry breaking).
// See dmi.cu
func AddDMI(Beff *data.Slice, m *data.Slice, Aex_red, Dex_red SymmLUT, regions *Bytes, mesh *data.Mesh) {
	cellsize := mesh.CellSize()
	N := Beff.Size()
	util.Argument(m.Size() == N)
	cfg := make3DConf(N)

	k_adddmi_async(Beff.DevPtr(X), Beff.DevPtr(Y), Beff.DevPtr(Z),
		m.DevPtr(X), m.DevPtr(Y), m.DevPtr(Z),
		unsafe.Pointer(Aex_red), unsafe.Pointer(Dex_red), regions.Ptr,
		float32(cellsize[X]*1e9), float32(cellsize[Y]*1e9), float32(cellsize[Z]*1e9), N[X], N[Y], N[Z], mesh.PBC_code(), cfg)
}