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MMF NEXUS

Documentation for MMFNEXUS.

UNDER DEVELOPMENT

This is the Julia implementation for the NEXUS+ algorithm. More information and standalone application can be found on our website in the future.

Installation

<!– The Multiscale Morphology Filter (MMF) NEXUS can be installed with the Julia package manager. From the Pkg Repl mode run:

add pkg thing in julia –>

For now, the Multiscale Morphology Filter (MMF) NEXUS can not be installed through the package manager yet. This will become available soon.

Usage

The basic usage of the NEXUS+ routine requries a density field with non-zero values everywhere. For optimal results, we suggest density field reconstructions using DTFE, or Phase-Space DTFE. How to reconstruct a density field from a particle distribution is found on the respective pages. The density field should be normalized, i.e. $\frac{\rho}{\rho_{\text{mean}}} = 1 + \delta$.

Give the normalized density field (densityField), we identify the cosmic web environments as follows:

using MMFNEXUS

# field and box parameters (example from the reconstruction of the illustris-3 box sampled at 256^3)
N = 256 # number of gridpoints per dimension
L = 75. # Box size in cMpc/h
totalMass = 4e8 * 455^3 # total mass contained in simulation box in Msun/h 

MMF_node, MMF_filament, MMF_wall, MMF_void = NEXUS_Plus(densityField, N, L, totalMass);

The resulting MMF_* outputs are BitArray's of size (N,N,N) where for each voxel, one of the morphological environments has the value 1 and all others are 0 to indicate to which environment it belongs. There are a number of optinal settings which are discussed in the tutorial section of the documentation.

Contributors

This Julia implementation is written by:

The original NEXUS+ algorithm published as NEXUS: tracing the cosmic web connection (Marius Cautun , Rien van de Weygaert , Bernard J. T. Jones) is written by:

  • Marius Cautun

We thank:

  • Ivan Spirov
  • Rien van de Weijgaert
  • Job Feldbrugge