VOBOZ (VOronoi BOund Zones)

VOBOZ is a halo-finding algorithm developed by Mark Neyrinck. It also has a complement, ZOBOV, which is a void-finding algorithm. VOBOZ uses Voronoi diagrams to measure the volume occupied by each particle, which in turn gives an estimate of its density.

We're trying out VOBOZ as a new halo finder, and this page documents a little bit about its usage, and some of the tests I've put it through.

Home page, downloads, etc.

Running

Running VOBOZ has 4 steps:

  1. Use vozinit to create a script for voz1b1 and voztie.
  2. Run the new script, creating the Voronoi diagrams.
  3. Create the joined zones using jovoz.
  4. Unbind energetic particle, and get the actual halo list with boz.

vozinit isn't too smart about paths, so you may have to do a quick find and replace in the resulting script. Or, put the executables somewhere in your path, and edit vozinit.c to remove any relative paths. Optionally, you can skip the first step, and call voz1b1 and voztie directly, but this would be tedious with a large number of divisions.

The help page has documentation on the inputs and outputs of each of the programs.

A script to do everything would look something like this: 

#!/bin/bash -f

VOBOZBIN=../bin

# create the run script
$VOBOZBIN/vozinit uniform_grid.raw 0.3 1.0 UG 

# script is named scr+suffix
./scrUG

# join the zones
$VOBOZBIN/jovoz adjUG.dat volUG.dat zonesUG.dat zonesUG.txt 0.01

# unbind particles
$VOBOZBIN/boz 1.0 0.3 1.0 uniform_grid.raw uniform_grid_vel.raw \
 zonesUG.dat halosUG.dat halosUG.txt 1.2

Testing

These tests are rudimentary, and were used to learn how VOBOZ works.

Attachments