Enzo 2.4 documentation

Executables, Arguments, and Outputs

This page is a summary of all of the binaries that are created after make; make install is run in the Enzo code bundle. They should be located in the bin directory. Links to the various pages of the manual that describe a particular binary are also included.


This is the main simulation code executable. See Running Enzo for more detailed information.

When an Enzo simulation is run, at every datastep several files are output, inserted into subdirectories. The most important of these are the files with no extension and those ending in .hierarchy, of which there will be one of each for each datadump. For more information on the format of Enzo output, see Enzo Output Formats.

usage: ./enzo.exe [options] param_file
   options are:
      -l(evel_of_extract) level
   -p(roject_to_plane) dimension
   -P(roject_to_plane version 2) dimension
      -m(smooth projection)
   -o(utput as particle data)
   -g (Write Potential field only)
   -M (Write smoothed DM field only)
   -F(riends-of-friends halo finder only)
   -C(ooling time write only)
   -i(nformation output)
   -V (show compiler options and flags)
   -s(tart  index region) dim0 [dim1] [dim2]
   -e(nd    index region) dim0 [dim1] [dim2]
   -b(egin  coordinate region) dim0 [dim1] [dim2]
   -f(inish coordinate region) dim0 [dim1] [dim2]

The -g, -M, and -C flags will read in the dataset given on the command line and write additional data fields to the same data files. When running with these flags (or the -F flag), the -r flag must also be given so that the code knows to read in a dataset. For example, to write out the cooling time to the output DD0001, do the following:

enzo.exe -r -C DD0001/DD0001


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


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


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>