Deprecated: Using Inits and Other Tools

This section has been largely replaced by Creating Cosmological Initial Conditions.

Building inits

This is the initial conditions generator. See Using inits for more detailed information. Initial conditions with a single initial grid or multiple nested grids can be created with this executable. Output file names are user-specified, but in a standard cosmology simulation with a single initial grid there should be a file containing baryon density information, another containing baryon velocity information, and two more files containing particle position and velocity information. Simulations with multiple grids will have a set of these files for each level, appended with numbers to make them unique.

usage: inits [options] param_file
   options are:
      -s(ubgrid) param_file

Building is as simple as the follwing.

~/enzo/src/ring $ cd ../inits/
~/enzo/src/inits $ make
Compiling enzo_module.src90
Updating DEPEND
Compiling acml_st1.src
Compiling XChunk_WriteIntField.C

This will produce inits.exe.


ring must be run on the simulation particle position and velocity information before a simulation is executed when the Enzo runtime parameter ParallelParticleIO is set to 1. Running ring generates files called PPos.nnnn PVel.nnnn where nnnn goes from 0001 to the total number of processors that are used for the simulation. These files contain the particle position and velocity information for particles that belong to each processor individually, and will be read into the code instead of the monolithic particle position and velocity files. Note that if ParallelParticleIO is on and ring is NOT run, the simulation will crash.

usage:  ring [string] <particle position file> <particle velocity file>

[string] can be one of the following: pv, pvm, pvt, or pvmt. p, v, m and t correspond to position, velocity, mass, and type, respectively. The most common [string] choice is ‘pv’. In that case, and if you use the default names for the particle position and velocity files, your usage will look like:

ring pv ParticlePositions ParticleVelocities

Building is as simple as the following.

~/enzo/src/enzo $ cd ../ring/
~/enzo/src/ring $ make
Updating DEPEND
Compiling Ring_Decomp.C
Compiling Enzo_Dims_create.C
Compiling Mpich_V1_Dims_create.c

This will produce ring.exe.


The second (and generally favored) method used for finding density peaks in an Enzo simulation. More information can be found here. A file called HopAnalysis.out is output which contains halo position and mass information.

enzohop [-b #] [-f #] [-t #] [-g] [-d] amr_file
  -b)egin region
  -f)inish region
  -t)hreshold for hop (default 160)
  -g)as particles also used (normally just dm)


anyl is the analysis package written in C, previously known as enzo_anyl. Although the analysis toolkit for enzo that’s being constantly updated is YT, anyl has its own value for some users. It creates radial, disk, vertical profiles for baryon (each species), dark matter, and star particles. Works with all AMR formats including HDF4 and packed HDF5.

usage: anyl.exe <amr file> <anyl parameter file>