genparam {snapshot}

Generates a Gadget paramter file

Description

Function to generator a legal Gadget paramter setup file. This has a sensible selection of defaults chosen for fairly small (non Cosmological) simulations.

Usage

genparam(ParamFile = "galaxy.param", ParamBase = "./HernTest/",
InitCondFile = "./HernStart.gdt", OutputDir = "./HernTest/", EnergyFile = "energy.txt",
InfoFile = "info.txt", TimingsFile = "timings.txt", CpuFile = "cpu.txt",
RestartFile = "restart", SnapshotFileBase = "snapshot",
OutputListFilename = "parameterfiles/output_list.txt", TimeLimitCPU = 36000,
ResubmitOn = 0, ResubmitCommand = "my-scriptfile", ICFormat = 1, SnapFormat = 1,
ComovingIntegrationOn = 0, TypeOfTimestepCriterion = 0, OutputListOn = 0,
PeriodicBoundariesOn = 0, TimeBegin = 0, TimeMax = 0.001, Omega0 = 0, OmegaLambda = 0,
OmegaBaryon = 0, HubbleParam = 1, BoxSize = 0, TimeBetSnapshot = 1e-05,
TimeOfFirstSnapshot = 0, CpuTimeBetRestartFile = 36000, TimeBetStatistics = 0.05,
NumFilesPerSnapshot = 1, NumFilesWrittenInParallel = 1, ErrTolIntAccuracy = 0.025,
CourantFac = 0.3, MaxSizeTimestep = 0.1, MinSizeTimestep = 0, ErrTolTheta = 0.5,
TypeOfOpeningCriterion = 1, ErrTolForceAcc = 0.005, TreeDomainUpdateFrequency = 0.1,
DesNumNgb = 32, MaxNumNgbDeviation = 8, ArtBulkViscConst = 1, InitGasTemp = 0,
MinGasTemp = 100, PartAllocFactor = 3.0, TreeAllocFactor = 4.8, BufferSize = 25,
UnitLength_in_cm = 3.085678e+21, UnitMass_in_g = 1.989e+43,
UnitVelocity_in_cm_per_s = 1e+05, GravityConstantInternal = 0,
MinGasHsmlFractional = 0.25, SofteningGas = 1e-04, SofteningHalo = 1e-04,
SofteningDisk = 0.4, SofteningBulge = 0.8, SofteningStars = 0, SofteningBndry = 0.1,
SofteningGasMaxPhys = 1e-04, SofteningHaloMaxPhys = 1e-04, SofteningDiskMaxPhys = 0.4,
SofteningBulgeMaxPhys = 0.8, SofteningStarsMaxPhys = 0, SofteningBndryMaxPhys = 0.1,
MaxRMSDisplacementFac = 0.2, NFWConcentration = 10, VirialMass = 200, FlatRadius = 1e-05,
DeltaVir = 200, addNFW = FALSE)

Arguments

ParamFile

Name for the paramter file

ParamBase

Base file path for the paramter file

InitCondFile

Full path of file containing initial conditions

OutputDir

Base directory in which to put the major Gadget outputs, including snapshots etc

EnergyFile

Name to give energy file

InfoFile

Name to give info file

TimingsFile

Name to give timings file

CpuFile

Name to give CPU file

RestartFile

Name to give restart file

SnapshotFileBase

Base name for snapshots, appended by snapshot number

OutputListFilename

Name of file containing output times / expansion factors

TimeLimitCPU

Max CPU time to use for Gadget run

ResubmitOn

Flag to tell super-computer there is a resubmit file

ResubmitCommand

Specific to super-computer resubmit command

ICFormat

Initial conditions format: PUT OPTIONS IN TABLE HERE

SnapFormat

Snapshot format: PUT OPTIONS IN TABLE HERE

ComovingIntegrationOn

Allow for expansion of Universe

TypeOfTimestepCriterion

Type of particle integrator- leave at 0

OutputListOn

Flag to tell it to use OutputListFilename as input

PeriodicBoundariesOn

Flag to turn on/off periodic box boundaries, only needed for large cosmological runs

TimeBegin

Time at the beginning of simulation

TimeMax

Max time to evolve particles to

Omega0

Total energy density

OmegaLambda

Cosmological constant energy density

OmegaBaryon

Baryonic energy density

HubbleParam

Value of H0/100 to be used

BoxSize

Length of box edge (important for cosmological runs only)

TimeBetSnapshot

Time between snapshots

TimeOfFirstSnapshot

Time at which to output first snapshot

CpuTimeBetRestartFile

How often to output full restart file

TimeBetStatistics

Time between energy.txt updates

NumFilesPerSnapshot

How many files to split snapshots over

NumFilesWrittenInParallel

How many files to split snapshots over (probably ignore)

ErrTolIntAccuracy

Orbital integration accuracy

CourantFac

Limit on time step compared to sound crossing time for hydro runs

MaxSizeTimestep

Maximum time step allowed

MinSizeTimestep

Minimum time step allowed

ErrTolTheta

Controls the accurary of integration (smaller is closer to direct N-body)

TypeOfOpeningCriterion

Barnes-Hut or modified opening criteria (probably ignore)

ErrTolForceAcc

Only used for modified opening criterion (use default)

TreeDomainUpdateFrequency

How often should a tree be constructed

DesNumNgb

Number of neighbours to use for denisty estimation in SPH

MaxNumNgbDeviation

How much tolerance is allowed when finding neighbours

ArtBulkViscConst

Artificial viscosity term (use default)

InitGasTemp

Initial gas temperature

MinGasTemp

Minimum gas temperature allowed in the run

PartAllocFactor

Memory buffer per particle per processor

TreeAllocFactor

Memory buffer for tree calculation

BufferSize

Total memory buffer between processors

UnitLength_in_cm

Assumed IC distance units in cm (default assumes Kpc for input)

UnitMass_in_g

Assumed mass of provided IC mass units in grams (default assumes 1e10 Msun for input)

UnitVelocity_in_cm_per_s

Assumed velocity of provided units in cm/s (default assumes km/s)

GravityConstantInternal

Internal units for g

MinGasHsmlFractional

Minimum multiplicitive factor for smoothing length in hyrdo gas

SofteningGas

Softening to use for gas particles

SofteningHalo

Softening to use for halo particles

SofteningDisk

Softening to use for disk particles

SofteningBulge

Softening to use for bulge particles

SofteningStars

Softening to use for star particles

SofteningBndry

Softening to use for boundary particles

SofteningGasMaxPhys

Physical softening to use for gas particles (only relevant for Cosmo run)

SofteningHaloMaxPhys

Physical softening to use for halo particles (only relevant for Cosmo run)

SofteningDiskMaxPhys

Physical softening to use for disk particles (only relevant for Cosmo run)

SofteningBulgeMaxPhys

Physical softening to use for bulge particles (only relevant for Cosmo run)

SofteningStarsMaxPhys

Physical softening to use for star particles (only relevant for Cosmo run)

SofteningBndryMaxPhys

Physical softening to use for boundary particles (only relevant for Cosmo run)

MaxRMSDisplacementFac

Biggest distance that a particle can move in a time step

NFWConcentration

Concentration of analytic NFW profile, addNFW must be set to TRUE

VirialMass

Mass within virial radius of analytic NFW profile, addNFW must be set to TRUE

FlatRadius

Forces the NFW profile to be cored (not cusped), addNFW must be set to TRUE

DeltaVir

Virial overdensity of NFW profile, addNFW must be set to TRUE

addNFW

Logic determining whether the analyic NFW specific paramters be added to the setup file? See above

Value

No value returned, called for the side-effect of writing out a Gadget paramter setup file.

Author(s)

Aaron Robotham

See Also

snapwrite,snapread,addhead

Examples

## Not run: 
genparam('example.param','Demo/Example1/')

## End(Not run)