== Null Result ==

This is a test to verify that a uniform distribution of particles will not return a bound group. [attachment:uniform_grid.c uniform_grid.c] is used to generate the initial grid, including a zero velocity field. Note that you'll need to edit {{{readfiles.c}}} to read this and the velocity field file in.

=== Create Grid ===

{{{
cable:~/packages/voboz1.1.1 rpwagner$ gcc uniform_grid.c
cable:~/packages/voboz1.1.1 rpwagner$ a.out
cable:~/packages/voboz1.1.1 rpwagner$ ls -l uniform_grid*
-rw-r--r--   1 rpwagner  rpwagner  772 Jan 14 10:37 uniform_grid.raw
-rw-r--r--   1 rpwagner  rpwagner  772 Jan 14 10:37 uniform_grid_vel.raw
cable:~/packages/voboz1.1.1 rpwagner$ 
}}}

=== {{{vozinit}}} ===

{{{vozinit}}} is kind of trivial; it creates a script to call the tools that do the real work. However, it is also a nice convenience. The inputs are: particle ''file name'', fractional ''buffer size'', comoving ''box length'', number of ''tiles per axis'', and a ''run name'''.

{{{
cable:~/packages/voboz1.1.1 rpwagner$ ./vozinit 
Wrong number of arguments.
arg1: position file
arg2: buffer size (default 0.1)
arg3: box size
arg4: number of divisions (default 2)
arg5: suffix describing this run

cable:~/packages/voboz1.1.1 rpwagner$ 
}}}

The buffers zones need to capture a significant enough number of particles to keep the guard particles away from the region of interest. For this case, the particles are separated by {{{0.25}}}, so the ''ghost'' zone needs to be at least {{{0.25}}}.

{{{
cable:~/packages/voboz1.1.1 rpwagner$ ./vozinit uniform_grid.raw 0.3 1 2 foo
}}}

The output is named {{{scr<}}}''run name''{{{>}}}.

{{{
cable:~/packages/voboz1.1.1 rpwagner$ cat scrfoo 
#!/bin/bash -f
./voz1b1 uniform_grid.raw 0.300000 1.000000 foo 2 0 0 0
./voz1b1 uniform_grid.raw 0.300000 1.000000 foo 2 0 0 1
./voz1b1 uniform_grid.raw 0.300000 1.000000 foo 2 0 1 0
./voz1b1 uniform_grid.raw 0.300000 1.000000 foo 2 0 1 1
./voz1b1 uniform_grid.raw 0.300000 1.000000 foo 2 1 0 0
./voz1b1 uniform_grid.raw 0.300000 1.000000 foo 2 1 0 1
./voz1b1 uniform_grid.raw 0.300000 1.000000 foo 2 1 1 0
./voz1b1 uniform_grid.raw 0.300000 1.000000 foo 2 1 1 1
./voztie 2 foo
}}}


=== {{{voz1b1}}} and {{{voztie}}} ===

Read the documentation about what these programs do. You can tell when something goes wrong, because you will either have no {{{part.<run name>.*}}} files, or you'll see a bunch of complaints about the guard particles. So, {{{<<blah, blah, blah>>}}} is what you hope for, not what you may see.

{{{
cable:~/packages/voboz1.1.1 rpwagner$ ./scrfoo 
<< blah, blah, blah >>
}}}

The {{{voz1b1}}} output are blocks of Voronoi diagrams, one per tile.

{{{
cable:~/packages/voboz1.1.1 rpwagner$ ls -1 part.foo.0*
part.foo.00.00.00
part.foo.00.00.01
part.foo.00.01.00
part.foo.00.01.01
part.foo.01.00.00
part.foo.01.00.01
part.foo.01.01.00
part.foo.01.01.01
cable:~/packages/voboz1.1.1 rpwagner$ 
}}}

The {{{voztie}}} output are an adjacency file and volume file.

{{{
cable:~/packages/voboz1.1.1 rpwagner$ ls -1 *dat
adjfoo.dat
volfoo.dat
cable:~/packages/voboz1.1.1 rpwagner$ 
}}}

=== {{{jovoz}}} ===

Hook'em together step. {{{jovoz}}} is fed the adjacency and volume file names, and the desired output names of a binary zone file and text listing of the zones. The final parameter controls the minimum density of halos.

{{{
cable:~/packages/voboz1.1.1 rpwagner$ ./jovoz 
Wrong number of arguments.
arg1: adjacency file
arg2: volume file
arg3: output zone membership file
arg4: output text file
arg5: volume tolerance (e.g. 1)
cable:~/packages/voboz1.1.1 rpwagner$ 
}}}

{{{
cable:~/packages/voboz1.1.1 rpwagner$ ./jovoz adjfoo.dat volfoo.dat foozone.dat foozone.txt 0.01
About to jump ...
Post-jump ...
64 initial haloes found
Found zone adjacencies
Volumes range from 1.000000e+00 to 1.000000e+00.
Maxprob = 1.000000.
about to sort ...
cable:~/packages/voboz1.1.1 rpwagner$ 
}}}

Some files.

{{{
cable:~/packages/voboz1.1.1 rpwagner$ ls -1 foozone.*
foozone.dat
foozone.txt
}}}

As expected, we get {{{64}}} zones, one per particle, each with the same density.

{{{
cable:~/packages/voboz1.1.1 rpwagner$ head foozone.txt 
64
0       1       1.000000e+00    1.000000e+00
1       1       1.000000e+00    1.000000e+00
2       1       1.000000e+00    1.000000e+00
3       1       1.000000e+00    1.000000e+00
4       1       1.000000e+00    1.000000e+00
5       1       1.000000e+00    1.000000e+00
6       1       1.000000e+00    1.000000e+00
7       1       1.000000e+00    1.000000e+00
8       1       1.000000e+00    1.000000e+00
cable:~/packages/voboz1.1.1 rpwagner$ 
}}}

=== {{{boz}}} ===

Unbinding step, with lots of arguments, but only one parameter (the last argument).

{{{
cable:~/packages/voboz1.1.1 rpwagner$ ./boz 
Wrong number of arguments.
arg1: box size
arg2: Omega_matter
arg3: scale factor a
arg4: position file
arg5: velocity file
arg6: input zone file
arg7: output bound zone file
arg8: output text file
arg9: unbinding f
}}}

I'm setting ''f'' here to {{{1.2}}} for no good reason. Read more about it in the paper.

{{{
cable:~/packages/voboz1.1.1 rpwagner$ 
cable:~/packages/voboz1.1.1 rpwagner$ ./boz 1.0 0.3 1.0 uniform_grid.raw uniform_grid_vel.raw foozone.dat foohalos.dat foohalos.txt 1.2
a = 1.000000 => Multiplying H0 by 1.000000e+00
cell, potconst = 0.007812,1.707547e-04
np = 64
np: 64, x: 0.000000,0.875000; y: 0.000000,0.875000; z: 0.000000,0.875000
vx: 0.000000,0.000000; vy: 0.000000,0.000000; vz: 0.000000,0.000000
np = 64, nhaloes = 64
Done! Outputting ...
Nhunb = 0
cable:~/packages/voboz1.1.1 rpwagner$
}}}

Hurrah! Final output is the actual number of halos found, which is zero, as expected.

{{{
cable:~/packages/voboz1.1.1 rpwagner$ cat foohalos.txt 
64      0
cable:~/packages/voboz1.1.1 rpwagner$ 
}}}