snapwrite {snapshot}

Write in Gadget snapshots

Description

This function allows the user to write standard format Gadget binaries. It can write the particle information and header information, which are provided as separate R objects.

Usage

snapwrite(part, head, file)

Arguments

part

A data.frame containing the main particle level information. Columns required are:

ID	particle ID
x	x position in units of Mpc
y	y position in units of Mpc
z	z position in units of Mpc
vx	x velocity in units of km/s
vy	y velocity in units of km/s
vz	z velocity in units of km/s
Mass	particle mass in units of Msun

head

A list containing various header information as list elements. These are:

Npart	Vector of length 6 containing the number of particles in this snapshot file, where:
	gas [1] / collisionless particles [2:6]
Massarr	Vector of length 6 containing the particle masses for the respective particle types
	in Npart
Time	Time of snapshot in units of km/s and kpc so 1 unit is ~10 Gyrs
z	Redshift of snapshot
FlagSfr	Star formation turned on/off
Nall	Vector of length 6 containing the number of particles in all snapshot files, where:
	gas [1] / collisionless particles [2:6]
FlagFeedback	Feedback turned on/off
FlagCooling	Cooling turned on/off
NumFiles	Number of files per snapshot- usually 1
BoxSize	Size of simulation box edge length in units of kpc
OmegaM	Omega matter of the simulation
OmegaL	Omega lambda of the simulation
h	Hubble constant divided by 100 used in the simulation
FlagAge	Stellar ages on/off
FlagMetals	Stellar metallacities on/off
NallHW	Tell Gadget to use large integers for the respective particle types in Npart
	- not usually necessary
flag_entr_ics	Entropy for gas on/off

file

The full path to the Gadget snapshot to be created.

Value

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

Author(s)

Aaron Robotham

See Also

snapread,addhead,genparam

Examples

## Not run: 
temp=snapwrite(snap$part,snap$head,'somepath/snapshot_XXX')

## End(Not run)