snap.gen.param: Generates a Gadget paramter file

In asgr/snapshot: Gadget N-body cosmological simulation code snapshot format 1 and 2 I/O utilities

Description

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

Usage

snap.gen.param(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 parameter setup file.

Author(s)

Aaron Robotham

See Also

snap.write.1, snap.read.1, snap.write.head.2, snap.write.block.2, snap.read.2

Examples

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

## End(Not run)

asgr/snapshot documentation built on Oct. 8, 2020, 2:52 p.m.