= VOBOZ (VOronoi BOund Zones) =

VOBOZ is a halo-finding algorithm developed by [http://www.ifa.hawaii.edu/~neyrinck Mark Neyrinck]. It also has a complement, ZOBOV, which is a void-finding algorithm. VOBOZ uses [http://en.wikipedia.org/wiki/Voronoi_diagram 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. 

[http://www.ifa.hawaii.edu/~neyrinck/voboz/ Home page, downloads, etc.]

== Running ==

Running VOBOZ has 4 steps:

 1. Use {{{vozinit}}} to create a script for {{{voz1b1}}} and {{{voztie}}}.
 1. Run the new script, creating the Voronoi diagrams.
 1. Create the joined zones using {{{jovoz}}}.
 1. 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 [http://www.ifa.hawaii.edu/~neyrinck/voboz/vobozhelp.html 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.

 * [wiki:VOBOZ/NullResult Null Result Test]
 * [wiki:VOBOZ/SingleHalo Single Halo Test]
 * [wiki:VOBOZ/EightHalo Eight Halo Test]