engine

package
v3.9.3+incompatible Latest Latest
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This package is not in the latest version of its module.

 Go to latest Published: Sep 30, 2016 License: CC-BY-3.0, Freetype, GPL-3.0-or-later Imports: 37 Imported by: 86

Documentation

Overview

engine does the simulation bookkeeping, I/O and GUI.

space-dependence: value: space-independent param: region-dependent parameter (always input) field: fully space-dependent field

TODO: godoc everything

Index

Constants

View Source 
const (
	TILE   = 2           // tile size in grains
	LAMBDA = TILE * TILE // expected grains per tile
)
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const (
	BACKWARD_EULER = -1
	EULER          = 1
	HEUN           = 2
	BOGAKISHAMPINE = 3
	RUNGEKUTTA     = 4
	DORMANDPRINCE  = 5
)

Arguments for SetSolver

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const (
	X = 0
	Y = 1
	Z = 2
)
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const (
	SCALAR = 1
	VECTOR = 3
)
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const CSS = `` /* 756-byte string literal not displayed */
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const MAX_GNUPLOTS = 5 // maximum allowed number of gnuplot processes
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const NREGION = 256 // maximum number of regions, limited by size of byte.
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const TableAutoflushRate = 5 // auto-flush table every X seconds
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const VERSION = "mumax 3.9.3"

Variables

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var (
	Ku1        = NewScalarParam("Ku1", "J/m3", "1st order uniaxial anisotropy constant", &ku1_red)
	Ku2        = NewScalarParam("Ku2", "J/m3", "2nd order uniaxial anisotropy constant", &ku2_red)
	Kc1        = NewScalarParam("Kc1", "J/m3", "1st order cubic anisotropy constant", &kc1_red)
	Kc2        = NewScalarParam("Kc2", "J/m3", "2nd order cubic anisotropy constant", &kc2_red)
	Kc3        = NewScalarParam("Kc3", "J/m3", "3rd order cubic anisotropy constant", &kc3_red)
	AnisU      = NewVectorParam("anisU", "", "Uniaxial anisotropy direction")
	AnisC1     = NewVectorParam("anisC1", "", "Cubic anisotropy direction #1")
	AnisC2     = NewVectorParam("anisC2", "", "Cubic anisotorpy directon #2")
	B_anis     = NewVectorField("B_anis", "T", "Anisotropy filed", AddAnisotropyField)
	Edens_anis = NewScalarField("Edens_anis", "J/m3", "Anisotropy energy density", AddAnisotropyEnergyDensity)
	E_anis     = NewScalarValue("E_anis", "J", "total anisotropy energy", GetAnisotropyEnergy)
)

Anisotropy variables

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var (
	Msat = NewScalarParam("Msat", "A/m", "Saturation magnetization",
		&Bsat, &lex2, &din2, &dbulk2, &ku1_red, &ku2_red, &kc1_red, &kc2_red, &kc3_red, &temp_red)
	Bsat        DerivedParam
	M_full      = NewVectorField("m_full", "A/m", "Unnormalized magnetization", SetMFull)
	B_demag     = NewVectorField("B_demag", "T", "Magnetostatic field", SetDemagField)
	Edens_demag = NewScalarField("Edens_demag", "J/m3", "Magnetostatic energy density", AddEdens_demag)
	E_demag     = NewScalarValue("E_demag", "J", "Magnetostatic energy", GetDemagEnergy)

	EnableDemag  = true // enable/disable global demag field
	NoDemagSpins = NewScalarParam("NoDemagSpins", "", "Disable magnetostatic interaction per-spin (set to 1 to disable)")

	DemagAccuracy = 6.0   // Demag accuracy (divide cubes in at most N^3 points)
	CacheDir      = ""    // directory for kernel cache
	TestDemag     = false // enable convolution self-test
)

Demag variables

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var (
	Edens_total = NewScalarField("Edens_total", "J/m3", "Total energy density", SetTotalEdens)
	E_total     = NewScalarValue("E_total", "J", "total energy", GetTotalEnergy)
)
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var (
	Aex   = NewScalarParam("Aex", "J/m", "Exchange stiffness", &lex2)
	Dind  = NewScalarParam("Dind", "J/m2", "Interfacial Dzyaloshinskii-Moriya strength", &din2)
	Dbulk = NewScalarParam("Dbulk", "J/m2", "Bulk Dzyaloshinskii-Moriya strength", &dbulk2)

	B_exch = NewVectorField("B_exch", "T", "Exchange field", AddExchangeField)

	E_exch     = NewScalarValue("E_exch", "J", "Total exchange energy", GetExchangeEnergy)
	Edens_exch = NewScalarField("Edens_exch", "J/m3", "Total exchange energy density", AddExchangeEnergyDensity)

	// Average exchange coupling with neighbors. Useful to debug inter-region exchange
	ExchCoupling = NewScalarField("ExchCoupling", "arb.", "Average exchange coupling with neighbors", exchangeDecode)
)
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var (
	BubblePos   = NewVectorValue("ext_bubblepos", "m", "Bubble core position", bubblePos)
	BubbleDist  = NewScalarValue("ext_bubbledist", "m", "Bubble traveled distance", bubbleDist)
	BubbleSpeed = NewScalarValue("ext_bubblespeed", "m/s", "Bubble velocity", bubbleSpeed)
)
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var (
	DWPos   = NewScalarValue("ext_dwpos", "m", "Position of the simulation window while following a domain wall", GetShiftPos) // TODO: make more accurate
	DWSpeed = NewScalarValue("ext_dwspeed", "m/s", "Speed of the simulation window while following a domain wall", getShiftSpeed)
)
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var (
	Ext_TopologicalCharge        = NewScalarValue("ext_topologicalcharge", "", "2D topological charge", GetTopologicalCharge)
	Ext_TopologicalChargeDensity = NewScalarField("ext_topologicalchargedensity", "1/m2",
		"2D topological charge density m·(m/∂x ❌ ∂m/∂y)", SetTopologicalChargeDensity)
)
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var (
	MaxAngle  = NewScalarValue("MaxAngle", "rad", "maximum angle between neighboring spins", GetMaxAngle) // TODO: Max(...)
	SpinAngle = NewScalarField("spinAngle", "rad", "Angle between neighboring spins", SetSpinAngle)
)
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var (
	MFM        = NewScalarField("MFM", "arb.", "MFM image", SetMFM)
	MFMLift    inputValue
	MFMTipSize inputValue
)
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var (
	DmSamples int     = 10   // number of dm to keep for convergence check
	StopMaxDm float64 = 1e-6 // stop minimizer if sampled dm is smaller than this
)
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var (
	Time float64 // time in seconds

	Inject                          = make(chan func()) // injects code in between time steps. Used by web interface.
	Dt_si                   float64 = 1e-15             // time step = dt_si (seconds) *dt_mul, which should be nice float32
	MinDt, MaxDt            float64                     // minimum and maximum time step
	MaxErr                  float64 = 1e-5              // maximum error/step
	Headroom                float64 = 0.8               // solver headroom, (Gustafsson, 1992, Control of Error and Convergence in ODE Solvers)
	LastErr, PeakErr        float64                     // error of last step, highest error ever
	LastTorque              float64                     // maxTorque of last time step
	NSteps, NUndone, NEvals int                         // number of good steps, undone steps
	FixDt                   float64                     // fixed time step?

)

Solver globals

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var (
	FilenameFormat = "%s%06d" // formatting string for auto filenames.
	SnapshotFormat = "jpg"    // user-settable snapshot format

)
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var (
	TotalShift                      float64                        // accumulated window shift (X) in meter
	ShiftMagL, ShiftMagR            data.Vector                    // when shifting m, put these value at the left/right edge.
	ShiftM, ShiftGeom, ShiftRegions bool        = true, true, true // should shift act on magnetization, geometry, regions?
)
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var (
	Temp = NewScalarParam("Temp", "K", "Temperature", &temp_red)

	E_therm     = NewScalarValue("E_therm", "J", "Thermal energy", GetThermalEnergy)
	Edens_therm = NewScalarField("Edens_therm", "J/m3", "Thermal energy density", AddThermalEnergyDensity)
	B_therm     thermField // Thermal effective field (T)
)
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var (
	Alpha        = NewScalarParam("alpha", "", "Landau-Lifshitz damping constant", &temp_red)
	Xi           = NewScalarParam("xi", "", "Non-adiabaticity of spin-transfer-torque")
	Pol          = NewScalarParam("Pol", "", "Electrical current polarization")
	Lambda       = NewScalarParam("Lambda", "", "Slonczewski Λ parameter")
	EpsilonPrime = NewScalarParam("EpsilonPrime", "", "Slonczewski secondairy STT term ε'")
	FrozenSpins  = NewScalarParam("frozenspins", "", "Defines spins that should be fixed") // 1 - frozen, 0 - free. TODO: check if it only contains 0/1 values

	FixedLayer                       = NewExcitation("FixedLayer", "", "Slonczewski fixed layer polarization")
	Torque                           = NewVectorField("torque", "T", "Total torque/γ0", SetTorque)
	LLTorque                         = NewVectorField("LLtorque", "T", "Landau-Lifshitz torque/γ0", SetLLTorque)
	STTorque                         = NewVectorField("STTorque", "T", "Spin-transfer torque/γ0", AddSTTorque)
	J                                = NewExcitation("J", "A/m2", "Electrical current density")
	MaxTorque                        = NewScalarValue("maxTorque", "T", "Maximum torque/γ0, over all cells", GetMaxTorque)
	GammaLL                  float64 = 1.7595e11 // Gyromagnetic ratio of spins, in rad/Ts
	Precess                          = true
	DisableZhangLiTorque             = false
	DisableSlonczewskiTorque         = false
)
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var (
	B_ext        = NewExcitation("B_ext", "T", "Externally applied field")
	Edens_zeeman = NewScalarField("Edens_Zeeman", "J/m3", "Zeeman energy density", AddEdens_zeeman)
	E_Zeeman     = NewScalarValue("E_Zeeman", "J", "Zeeman energy", GetZeemanEnergy)
)
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var AddEdens_demag = makeEdensAdder(&B_demag, -0.5)
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var AddEdens_zeeman = makeEdensAdder(B_ext, -1)
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var AddExchangeEnergyDensity = makeEdensAdder(&B_exch, -0.5) // TODO: normal func
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var AddThermalEnergyDensity = makeEdensAdder(&B_therm, -1)
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var B_eff = NewVectorField("B_eff", "T", "Effective field", SetEffectiveField)
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var CorePos = NewVectorValue("ext_corepos", "m", "Vortex core position (x,y) + polarization (z)", corePos)
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var DWTiltPMA = NewScalarValue("ext_dwtilt", "rad", "PMA domain wall tilt", dwTiltPMA)

PMA domain wall tilt assuming straight wall.

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var (
	InputFile string
)
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var M magnetization // reduced magnetization (unit length)
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var StartTime = time.Now()
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var (
	StringFromOutputFormat = map[OutputFormat]string{
		OVF1_TEXT:   "ovf",
		OVF1_BINARY: "ovf",
		OVF2_TEXT:   "ovf",
		OVF2_BINARY: "ovf",
		DUMP:        "dump"}
)
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var Table = *newTable("table") // output handle for tabular data (average magnetization etc.)
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var (
	Timeout = 3 * time.Second // exit finished simulation this long after browser was closed
)

global GUI state stores what is currently shown in the web page.

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var UNAME = VERSION + " " + runtime.GOOS + "_" + runtime.GOARCH + " " + runtime.Version() + " (" + runtime.Compiler + ")"
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var World = script.NewWorld()

holds the script state (variables etc)

Functions

func AddAnisotropyEnergyDensity 

func AddAnisotropyEnergyDensity(dst *data.Slice)

func AddAnisotropyField 

func AddAnisotropyField(dst *data.Slice)

Add the anisotropy field to dst

func AddExchangeField 

func AddExchangeField(dst *data.Slice)

Adds the current exchange field to dst

func AddSTTorque 

func AddSTTorque(dst *data.Slice)

Adds the current spin transfer torque to dst

func AutoSave 

func AutoSave(q outputField, period float64)

Register quant to be auto-saved every period. period == 0 stops autosaving.

func AutoSnapshot 

func AutoSnapshot(q outputField, period float64)

Register quant to be auto-saved as image, every period.

func Break 

func Break()

func CenterWall 

func CenterWall(magComp int)

This post-step function centers the simulation window on a domain wall between up-down (or down-up) domains (like in perpendicular media). E.g.: 

PostStep(CenterPMAWall)

func CheckRecoverable 

func CheckRecoverable(err error)

func Close 

func Close()

Cleanly exits the simulation, assuring all output is flushed.

func CompileFile 

func CompileFile(fname string) (*script.BlockStmt, error)

func Const 

func Const(e script.Expr) bool

checks if a script expression contains t (time)

func Crop 

func Crop(parent outputField, x1, x2, y1, y2, z1, z2 int) *cropped

func CropLayer 

func CropLayer(parent outputField, layer int) *cropped

func CropRegion 

func CropRegion(parent outputField, region int) *cropped

func CropX 

func CropX(parent outputField, x1, x2 int) *cropped

func CropY 

func CropY(parent outputField, y1, y2 int) *cropped

func CropZ 

func CropZ(parent outputField, z1, z2 int) *cropped

func DeclConst 

func DeclConst(name string, value float64, doc string)

Add a constant to the script world

func DeclFunc 

func DeclFunc(name string, f interface{}, doc string)

Add a function to the script world

func DeclLValue 

func DeclLValue(name string, value LValue, doc string)

Add an LValue to the script world. Assign to LValue invokes SetValue()

func DeclROnly 

func DeclROnly(name string, value interface{}, doc string)

Add a read-only variable to the script world. It can be changed, but not by the user.

func DeclTVar 

func DeclTVar(name string, value interface{}, doc string)

Hack for fixing the closure caveat: Defines "t", the time variable, handled specially by Fix()

func DeclVar 

func DeclVar(name string, value interface{}, doc string)

Add a (pointer to) variable to the script world

func DefRegion 

func DefRegion(id int, s Shape)

Define a region with id (0-255) to be inside the Shape.

func DefRegionCell 

func DefRegionCell(id int, x, y, z int)

func DoOutput 

func DoOutput()

Periodically called by run loop to save everything that's needed at this time.

func DotProduct 

func DotProduct(a, b outputField) *dotProduct

DotProduct creates a new quantity that is the dot product of quantities a and b. E.g.: 

DotProct(&M, &B_ext)

func Download 

func Download(q outputField) *data.Slice

Download a quantity to host, or just return its data when already on host.

func EnableUnsafe 

func EnableUnsafe()

func Eval 

func Eval(code string)

func Eval1Line 

func Eval1Line(code string) interface{}

func EvalFile 

func EvalFile(code *script.BlockStmt)

evaluate code, exit on error (behavior for input files)

func Exit 

func Exit()

func Expect 

func Expect(msg string, have, want, maxError float64)

Test if have lies within want +/- maxError, and print suited message.

func ExpectV 

func ExpectV(msg string, have, want data.Vector, maxErr float64)

func Export 

func Export(q interface {
	Name() string
	Unit() string
}, doc string)

func FifoRing 

func FifoRing(length int) fifoRing

func Fprintln 

func Fprintln(filename string, msg ...interface{})

Append msg to file. Used to write aggregated output of many simulations in one file.

func FreezeSpins 

func FreezeSpins(dst *data.Slice)

func GUIAdd 

func GUIAdd(name string, value interface{})

func GetAnisotropyEnergy 

func GetAnisotropyEnergy() float64

Returns anisotropy energy in joules.

func GetBusy 

func GetBusy() bool

func GetDemagEnergy 

func GetDemagEnergy() float64

Returns the current demag energy in Joules.

func GetExchangeEnergy 

func GetExchangeEnergy() float64

Returns the current exchange energy in Joules.

func GetMaxAngle 

func GetMaxAngle() float64

func GetMaxTorque 

func GetMaxTorque() float64

Gets

func GetShiftPos 

func GetShiftPos() float64

position of the window lab frame

func GetThermalEnergy 

func GetThermalEnergy() float64

func GetTopologicalCharge 

func GetTopologicalCharge() float64

func GetTotalEnergy 

func GetTotalEnergy() float64

Returns the total energy in J.

func GetZeemanEnergy 

func GetZeemanEnergy() float64

func GoServe 

func GoServe(addr string) string

func Index2Coord 

func Index2Coord(ix, iy, iz int) data.Vector

converts cell index to coordinate, internal coordinates

func InitIO 

func InitIO(inputfile, od string, force bool)

SetOD sets the output directory where auto-saved files will be stored. The -o flag can also be used for this purpose.

func InjectAndWait 

func InjectAndWait(task func())

inject code into engine and wait for it to complete.

func LoadFile 

func LoadFile(fname string) *data.Slice

Read a magnetization state from .dump file.

func LogErr 

func LogErr(msg ...interface{})

func LogIn 

func LogIn(msg ...interface{})

func LogOut 

func LogOut(msg ...interface{})

func Mesh 

func Mesh() *data.Mesh

func Minimize 

func Minimize()

func NewScalarMask 

func NewScalarMask(Nx, Ny, Nz int) *data.Slice

func NewSlice 

func NewSlice(ncomp, Nx, Ny, Nz int) *data.Slice

Returns a new new slice (3D array) with given number of components and size.

func NewVectorMask 

func NewVectorMask(Nx, Ny, Nz int) *data.Slice

func OD 

func OD() string

func PostStep 

func PostStep(f func())

Register function f to be called after every time step. Typically used, e.g., to manipulate the magnetization.

func Relax 

func Relax()

func RemoveLRSurfaceCharge 

func RemoveLRSurfaceCharge(region int, mxLeft, mxRight float64)

For a nanowire magnetized in-plane, with mx = mxLeft on the left end and mx = mxRight on the right end (both -1 or +1), add a B field needed to compensate for the surface charges on the left and right edges. This will mimic an infinitely long wire.

func Run 

func Run(seconds float64)

Run the simulation for a number of seconds.

func RunInteractive 

func RunInteractive()

Runs as long as browser is connected to gui.

func RunWhile 

func RunWhile(condition func() bool)

Runs as long as condition returns true, saves output.

func SanityCheck 

func SanityCheck()

func Save 

func Save(q outputField)

Save once, with auto file name

func SaveAs 

func SaveAs(q outputField, fname string)

Save under given file name (transparent async I/O).

func ScaleInterExchange 

func ScaleInterExchange(region1, region2 int, scale float64)

Scales the heisenberg exchange interaction between region1 and 2. Scale = 1 means the harmonic mean over the regions of Aex/Msat.

func SetBusy 

func SetBusy(b bool)

We set SetBusy(true) when the simulation is too busy too accept GUI input on Inject channel. E.g. during kernel init.

func SetCellSize 

func SetCellSize(cx, cy, cz float64)

func SetDemagField 

func SetDemagField(dst *data.Slice)

Sets dst to the current demag field

func SetEffectiveField 

func SetEffectiveField(dst *data.Slice)

Sets dst to the current effective field (T). TODO: extensible slice

func SetGeom 

func SetGeom(s Shape)

func SetGridSize 

func SetGridSize(Nx, Ny, Nz int)

func SetLLTorque 

func SetLLTorque(dst *data.Slice)

Sets dst to the current Landau-Lifshitz torque

func SetMFM 

func SetMFM(dst *data.Slice)

func SetMFull 

func SetMFull(dst *data.Slice)

Sets dst to the full (unnormalized) magnetization in A/m

func SetMesh 

func SetMesh(Nx, Ny, Nz int, cellSizeX, cellSizeY, cellSizeZ float64, pbcx, pbcy, pbcz int)

Set the simulation mesh to Nx x Ny x Nz cells of given size. Can be set only once at the beginning of the simulation. TODO: dedup arguments from globals

func SetPBC 

func SetPBC(nx, ny, nz int)

func SetSolver 

func SetSolver(typ int)

func SetSpinAngle 

func SetSpinAngle(dst *data.Slice)

func SetTopologicalChargeDensity 

func SetTopologicalChargeDensity(dst *data.Slice)

func SetTorque 

func SetTorque(dst *data.Slice)

Sets dst to the current total torque TODO: extensible

func SetTotalEdens 

func SetTotalEdens(dst *data.Slice)

Set dst to total energy density in J/m3

func Shift 

func Shift(dx int)

shift the simulation window over dx cells in X direction

func Snapshot 

func Snapshot(q outputField)

Save image once, with auto file name

func Steps 

func Steps(n int)

Run the simulation for a number of steps.

func TableAdd 

func TableAdd(col TableData)

func TableAddVariable 

func TableAddVariable(x script.ScalarFunction, name, unit string)

func TableAutoSave 

func TableAutoSave(period float64)

func TablePrint 

func TablePrint(msg ...interface{})

func TableSave 

func TableSave()

func ThermSeed 

func ThermSeed(seed int)

Seeds the thermal noise generator

func Vector 

func Vector(x, y, z float64) data.Vector

Constructs a vector

func Voronoi 

func Voronoi(grainsize float64, numRegions, seed int)

Types

type BackwardEuler 

type BackwardEuler struct {
	// contains filtered or unexported fields
}

func (*BackwardEuler) Free 

func (s *BackwardEuler) Free()

func (*BackwardEuler) Step 

func (s *BackwardEuler) Step()

Euler method, can be used as solver.Step.

type Config 

type Config func(x, y, z float64) data.Vector

Magnetic configuration returns m vector for position (x,y,z)

func AntiVortex 

func AntiVortex(circ, pol int) Config

func BlochSkyrmion 

func BlochSkyrmion(charge, pol int) Config

func NeelSkyrmion 

func NeelSkyrmion(charge, pol int) Config

func RandomMag 

func RandomMag() Config

func RandomMagSeed 

func RandomMagSeed(seed int) Config

func TwoDomain 

func TwoDomain(mx1, my1, mz1, mxwall, mywall, mzwall, mx2, my2, mz2 float64) Config

Make a 2-domain configuration with domain wall. (mx1, my1, mz1) and (mx2, my2, mz2) are the magnetizations in the left and right domain, respectively. (mxwall, mywall, mzwall) is the magnetization in the wall. The wall is smoothed over a few cells so it will easily relax to its ground state. E.g.: 

TwoDomain(1,0,0,  0,1,0,  -1,0,0) // head-to-head domains with transverse (Néel) wall
TwoDomain(1,0,0,  0,0,1,  -1,0,0) // head-to-head domains with perpendicular (Bloch) wall
TwoDomain(0,0,1,  1,0,0,   0,0,-1)// up-down domains with Bloch wall

func Uniform 

func Uniform(mx, my, mz float64) Config

Returns a uniform magnetization state. E.g.: 

M = Uniform(1, 0, 0)) // saturated along X

func Vortex 

func Vortex(circ, pol int) Config

Make a vortex magnetization with given circulation and core polarization (+1 or -1). The core is smoothed over a few exchange lengths and should easily relax to its ground state.

func VortexWall 

func VortexWall(mleft, mright float64, circ, pol int) Config

Make a vortex wall configuration.

func (Config) Add 

func (c Config) Add(weight float64, other Config) Config

func (Config) RotZ 

func (c Config) RotZ(θ float64) Config

Rotates the configuration around the Z-axis, over θ radians.

func (Config) Scale 

func (c Config) Scale(sx, sy, sz float64) Config

Scale returns a scaled copy of configuration c.

func (Config) Transl 

func (c Config) Transl(dx, dy, dz float64) Config

Transl returns a translated copy of configuration c. E.g.: 

M = Vortex(1, 1).Transl(100e-9, 0, 0)  // vortex with center at x=100nm

type DataTable 

type DataTable struct {
	// contains filtered or unexported fields
}

func (*DataTable) Add 

func (t *DataTable) Add(output TableData)

func (*DataTable) AddVariable 

func (t *DataTable) AddVariable(x script.ScalarFunction, name, unit string)

func (*DataTable) Flush 

func (t *DataTable) Flush() error

func (*DataTable) NComp 

func (i *DataTable) NComp() int

func (*DataTable) Name 

func (i *DataTable) Name() string

func (*DataTable) Println 

func (t *DataTable) Println(msg ...interface{})

func (*DataTable) Save 

func (t *DataTable) Save()

func (*DataTable) Unit 

func (i *DataTable) Unit() string

func (*DataTable) Write 

func (t *DataTable) Write(p []byte) (int, error)

type DerivedParam 

type DerivedParam struct {
	// contains filtered or unexported fields
}

parameter derived from others (not directly settable). E.g.: Bsat derived from Msat

func NewDerivedParam 

func NewDerivedParam(nComp int, parents []parent, updater func(*DerivedParam)) *DerivedParam

func (*DerivedParam) GetRegion 

func (p *DerivedParam) GetRegion(r int) []float64

Get value in region r.

func (*DerivedParam) NComp 

func (b *DerivedParam) NComp() int

func (*DerivedParam) Slice 

func (p *DerivedParam) Slice() (*data.Slice, bool)

uncompress the table to a full array with parameter values per cell.

type Euler 

type Euler struct{}

func (*Euler) Free 

func (_ *Euler) Free()

func (*Euler) Step 

func (_ *Euler) Step()

Euler method, can be used as solver.Step.

type Excitation 

type Excitation struct {
	// contains filtered or unexported fields
}

An excitation, typically field or current, can be defined region-wise plus extra mask*multiplier terms. TODO: unify with param.

func NewExcitation 

func NewExcitation(name, unit, desc string) *Excitation

func (*Excitation) Add 

func (e *Excitation) Add(mask *data.Slice, f script.ScalarFunction)

Add an extra mask*multiplier term to the excitation.

func (*Excitation) AddGo 

func (e *Excitation) AddGo(mask *data.Slice, mul func() float64)

An Add(mask, f) equivalent for Go use

func (*Excitation) AddTo 

func (e *Excitation) AddTo(dst *data.Slice)

func (*Excitation) Average 

func (e *Excitation) Average() data.Vector

func (*Excitation) Comp 

func (e *Excitation) Comp(c int) ScalarField

func (*Excitation) Eval 

func (e *Excitation) Eval() interface{}

func (*Excitation) InputType 

func (e *Excitation) InputType() reflect.Type

func (*Excitation) IsUniform 

func (e *Excitation) IsUniform() bool

func (*Excitation) Mesh 

func (e *Excitation) Mesh() *data.Mesh

func (*Excitation) NComp 

func (e *Excitation) NComp() int

func (*Excitation) Name 

func (e *Excitation) Name() string

func (*Excitation) Region 

func (e *Excitation) Region(r int) *vOneReg

func (*Excitation) RemoveExtraTerms 

func (e *Excitation) RemoveExtraTerms()

After resizing the mesh, the extra terms don't fit the grid anymore and there is no reasonable way to resize them. So remove them and have the user re-add them.

func (*Excitation) Set 

func (e *Excitation) Set(v data.Vector)

func (*Excitation) SetRegion 

func (e *Excitation) SetRegion(region int, f script.VectorFunction)

func (*Excitation) SetRegionFn 

func (e *Excitation) SetRegionFn(region int, f func() [3]float64)

func (*Excitation) SetValue 

func (e *Excitation) SetValue(v interface{})

func (*Excitation) Slice 

func (e *Excitation) Slice() (*data.Slice, bool)

func (*Excitation) Type 

func (e *Excitation) Type() reflect.Type

func (*Excitation) Unit 

func (e *Excitation) Unit() string

type Heun 

type Heun struct{}

Adaptive Heun solver.

func (*Heun) Free 

func (_ *Heun) Free()

func (*Heun) Step 

func (_ *Heun) Step()

Adaptive Heun method, can be used as solver.Step

type Info 

type Info interface {
	Name() string // number of components (scalar, vector, ...)
	Unit() string // name used for output file (e.g. "m")
	NComp() int   // unit, e.g. "A/m"
}

The Info interface defines the bare minimum methods a quantity must implement to be accessible for scripting and I/O.

type LValue 

type LValue interface {
	SetValue(interface{}) // assigns a new value
	Eval() interface{}    // evaluate and return result (nil for void)
	Type() reflect.Type   // type that can be assigned and will be returned by Eval
}

LValue is settable

type Minimizer 

type Minimizer struct {
	// contains filtered or unexported fields
}

func (*Minimizer) Free 

func (mini *Minimizer) Free()

func (*Minimizer) Step 

func (mini *Minimizer) Step()

type OutputFormat 

type OutputFormat int
const (
	OVF1_TEXT OutputFormat = iota + 1
	OVF1_BINARY
	OVF2_TEXT
	OVF2_BINARY
	DUMP
)

type Param 

type Param interface {
	NComp() int
	Name() string
	Unit() string

	IsUniform() bool
	// contains filtered or unexported methods
}

displayable quantity in GUI Parameters section

type RK23 

type RK23 struct {
	// contains filtered or unexported fields
}

Bogacki-Shampine solver. 3rd order, 3 evaluations per step, adaptive step. 

http://en.wikipedia.org/wiki/Bogacki-Shampine_method

k1 = f(tn, yn)
k2 = f(tn + 1/2 h, yn + 1/2 h k1)
k3 = f(tn + 3/4 h, yn + 3/4 h k2)
y{n+1}  = yn + 2/9 h k1 + 1/3 h k2 + 4/9 h k3            // 3rd order
k4 = f(tn + h, y{n+1})
z{n+1} = yn + 7/24 h k1 + 1/4 h k2 + 1/3 h k3 + 1/8 h k4 // 2nd order

func (*RK23) Free 

func (rk *RK23) Free()

func (*RK23) Step 

func (rk *RK23) Step()

type RK4 

type RK4 struct {
}

func (*RK4) Free 

func (_ *RK4) Free()

func (*RK4) Step 

func (rk *RK4) Step()

type RK45DP 

type RK45DP struct {
	// contains filtered or unexported fields
}

func (*RK45DP) Free 

func (rk *RK45DP) Free()

func (*RK45DP) Step 

func (rk *RK45DP) Step()

type Regions 

type Regions struct {
	// contains filtered or unexported fields
}

stores the region index for each cell

func (*Regions) Average 

func (r *Regions) Average() float64

func (*Regions) GetCell 

func (r *Regions) GetCell(ix, iy, iz int) int

func (*Regions) Gpu 

func (r *Regions) Gpu() *cuda.Bytes

Get the region data on GPU

func (*Regions) HostArray 

func (r *Regions) HostArray() [][][]byte

func (*Regions) HostList 

func (r *Regions) HostList() []byte

func (*Regions) LoadFile 

func (r *Regions) LoadFile(fname string)

Load regions from ovf file, use first component. Regions should be between 0 and 256

func (*Regions) Mesh 

func (r *Regions) Mesh() *data.Mesh

func (*Regions) NComp 

func (i *Regions) NComp() int

func (*Regions) Name 

func (i *Regions) Name() string

func (*Regions) SetCell 

func (r *Regions) SetCell(ix, iy, iz int, region int)

Set the region of one cell

func (*Regions) Slice 

func (r *Regions) Slice() (*data.Slice, bool)

Get returns the regions as a slice of floats, so it can be output.

func (*Regions) Unit 

func (i *Regions) Unit() string

type ScalarField 

type ScalarField struct {
	// contains filtered or unexported fields
}

ScalarField enhances an outputField with methods specific to a space-dependent scalar quantity.

func AsScalarField 

func AsScalarField(q outputField) ScalarField

AsScalarField promotes a quantity to a ScalarField, enabling convenience methods particular to scalars.

func Comp 

func Comp(parent outputField, c int) ScalarField

Comp returns vector component c of the parent Quantity

func NewScalarField 

func NewScalarField(name, unit, desc string, f func(dst *data.Slice)) ScalarField

NewVectorField constructs an outputable space-dependent scalar quantity whose value is provided by function f.

func (ScalarField) Average 

func (s ScalarField) Average() float64

func (ScalarField) Region 

func (s ScalarField) Region(r int) ScalarField

type ScalarParam 

type ScalarParam struct {
	// contains filtered or unexported fields
}

specialized param with 1 component

func NewScalarParam 

func NewScalarParam(name, unit, desc string, children ...derived) *ScalarParam

TODO: auto derived

func (*ScalarParam) Average 

func (p *ScalarParam) Average() float64

func (*ScalarParam) Eval 

func (p *ScalarParam) Eval() interface{}

func (*ScalarParam) GetRegion 

func (p *ScalarParam) GetRegion(region int) float64

func (*ScalarParam) InputType 

func (p *ScalarParam) InputType() reflect.Type

func (*ScalarParam) IsUniform 

func (p *ScalarParam) IsUniform() bool

func (*ScalarParam) Mesh 

func (p *ScalarParam) Mesh() *data.Mesh

func (*ScalarParam) Name 

func (p *ScalarParam) Name() string

func (*ScalarParam) Region 

func (p *ScalarParam) Region(r int) *sOneReg

func (*ScalarParam) Set 

func (p *ScalarParam) Set(v float64)

func (*ScalarParam) SetRegion 

func (p *ScalarParam) SetRegion(region int, f script.ScalarFunction)

func (*ScalarParam) SetRegionFuncGo 

func (p *ScalarParam) SetRegionFuncGo(region int, f func() float64)

func (*ScalarParam) SetRegionValueGo 

func (p *ScalarParam) SetRegionValueGo(region int, v float64)

func (*ScalarParam) SetValue 

func (p *ScalarParam) SetValue(v interface{})

func (*ScalarParam) Type 

func (p *ScalarParam) Type() reflect.Type

func (*ScalarParam) Unit 

func (p *ScalarParam) Unit() string

type ScalarValue 

type ScalarValue struct {
	// contains filtered or unexported fields
}

ScalarValue enhances an outputValue with methods specific to a space-independent scalar quantity (e.g. total energy).

func NewScalarValue 

func NewScalarValue(name, unit, desc string, f func() float64) *ScalarValue

NewScalarValue constructs an outputable space-independent scalar quantity whose value is provided by function f.

func (ScalarValue) Average 

func (s ScalarValue) Average() float64

func (ScalarValue) Get 

func (s ScalarValue) Get() float64

type Shape 

type Shape func(x, y, z float64) bool

geometrical shape for setting sample geometry

func Cell 

func Cell(ix, iy, iz int) Shape

Single cell with given index

func Circle 

func Circle(diam float64) Shape

func Cuboid 

func Cuboid(sidex, sidey, sidez float64) Shape

3D Rectangular slab with given sides.

func Cylinder 

func Cylinder(diam, height float64) Shape

cylinder along z.

func Ellipse 

func Ellipse(diamx, diamy float64) Shape

func Ellipsoid 

func Ellipsoid(diamx, diamy, diamz float64) Shape

Ellipsoid with given diameters

func GrainRoughness 

func GrainRoughness(grainsize, zmin, zmax float64, seed int) Shape

func ImageShape 

func ImageShape(fname string) Shape

func Layer 

func Layer(index int) Shape

func Layers 

func Layers(a, b int) Shape

Cell layers #a (inclusive) up to #b (exclusive).

func Rect 

func Rect(sidex, sidey float64) Shape

2D Rectangle with given sides.

func Square 

func Square(side float64) Shape

2D square with given side.

func Universe 

func Universe() Shape

func XRange 

func XRange(a, b float64) Shape

All cells with x-coordinate between a and b

func YRange 

func YRange(a, b float64) Shape

All cells with y-coordinate between a and b

func ZRange 

func ZRange(a, b float64) Shape

All cells with z-coordinate between a and b

func (Shape) Add 

func (a Shape) Add(b Shape) Shape

Union of shapes a and b (logical OR).

func (Shape) Intersect 

func (a Shape) Intersect(b Shape) Shape

Intersection of shapes a and b (logical AND).

func (Shape) Inverse 

func (s Shape) Inverse() Shape

Inverse (outside) of shape (logical NOT).

func (Shape) Repeat 

func (s Shape) Repeat(periodX, periodY, periodZ float64) Shape

Infinitely repeats the shape with given period in x, y, z. A period of 0 or infinity means no repetition.

func (Shape) RotX 

func (s Shape) RotX(θ float64) Shape

Rotates the shape around the X-axis, over θ radians.

func (Shape) RotY 

func (s Shape) RotY(θ float64) Shape

Rotates the shape around the Y-axis, over θ radians.

func (Shape) RotZ 

func (s Shape) RotZ(θ float64) Shape

Rotates the shape around the Z-axis, over θ radians.

func (Shape) Scale 

func (s Shape) Scale(sx, sy, sz float64) Shape

Scale returns a scaled copy of the shape.

func (Shape) Sub 

func (a Shape) Sub(b Shape) Shape

Removes b from a (logical a AND NOT b)

func (Shape) Transl 

func (s Shape) Transl(dx, dy, dz float64) Shape

Transl returns a translated copy of the shape.

func (Shape) Xor 

func (a Shape) Xor(b Shape) Shape

Logical XOR of shapes a and b

type Stepper 

type Stepper interface {
	Step() // take time step using solver globals
	Free() // free resources, if any (e.g.: RK23 previous torque)
}

Time stepper like Euler, Heun, RK23

type TableData 

type TableData interface {
	Name() string
	Unit() string
	NComp() int
	// contains filtered or unexported methods
}

can be saved in table

type UserErr 

type UserErr string

Special error that is not fatal when paniced on and called from GUI E.g.: try to set bad grid size: panic on UserErr, recover, print error, carry on.

func (UserErr) Error 

func (e UserErr) Error() string

type VectorField 

type VectorField struct {
	// contains filtered or unexported fields
}

VectorField enhances an outputField with methods specific to a space-dependent vector quantity.

func AsVectorField 

func AsVectorField(q outputField) VectorField

AsVectorField promotes a quantity to a VectorField, enabling convenience methods particular to vectors.

func NewVectorField 

func NewVectorField(name, unit, desc string, f func(dst *data.Slice)) VectorField

NewVectorField constructs an outputable space-dependent vector quantity whose value is provided by function f.

func (VectorField) Average 

func (v VectorField) Average() data.Vector

func (VectorField) Comp 

func (v VectorField) Comp(c int) ScalarField

func (VectorField) Region 

func (v VectorField) Region(r int) VectorField

type VectorParam 

type VectorParam struct {
	// contains filtered or unexported fields
}

vector input parameter, settable by user

func NewVectorParam 

func NewVectorParam(name, unit, desc string) *VectorParam

func (*VectorParam) Average 

func (p *VectorParam) Average() data.Vector

func (*VectorParam) Comp 

func (p *VectorParam) Comp(c int) ScalarField

func (*VectorParam) Eval 

func (p *VectorParam) Eval() interface{}

func (*VectorParam) GetRegion 

func (p *VectorParam) GetRegion(region int) [3]float64

func (*VectorParam) InputType 

func (p *VectorParam) InputType() reflect.Type

func (*VectorParam) IsUniform 

func (p *VectorParam) IsUniform() bool

func (*VectorParam) Mesh 

func (p *VectorParam) Mesh() *data.Mesh

func (*VectorParam) Name 

func (p *VectorParam) Name() string

func (*VectorParam) Region 

func (p *VectorParam) Region(r int) *vOneReg

func (*VectorParam) SetRegion 

func (p *VectorParam) SetRegion(region int, f script.VectorFunction)

func (*VectorParam) SetRegionFn 

func (p *VectorParam) SetRegionFn(region int, f func() [3]float64)

func (*VectorParam) SetValue 

func (p *VectorParam) SetValue(v interface{})

func (*VectorParam) Type 

func (p *VectorParam) Type() reflect.Type

func (*VectorParam) Unit 

func (p *VectorParam) Unit() string

type VectorValue 

type VectorValue struct {
	// contains filtered or unexported fields
}

VectorValue enhances an outputValue with methods specific to a space-independent vector quantity (e.g. averaged magnetization).

func NewVectorValue 

func NewVectorValue(name, unit, desc string, f func() []float64) *VectorValue

NewVectorValue constructs an outputable space-independent vector quantity whose value is provided by function f.

func (*VectorValue) Average 

func (v *VectorValue) Average() data.Vector

func (*VectorValue) Get 

func (v *VectorValue) Get() data.Vector

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