README

SImple HOD
----------

.. image:: https://travis-ci.org/bccp/simplehod.svg?branch=master
    :target: https://travis-ci.org/bccp/simplehod


This is an adoption of Martin White's simple HOD scheme into Python.

No bloat intended. Just the bare basic stuff.

- 'simplehod.hod' is the main entry point.

- If only intended to draw satellites from NFW, use `simplehod.mksat`. 

- Drawing centrals, use `simplehod.mkcen`.

- computing expected number of galaxies, use `simplehod.mkn`;
  use `simplehod.mknint` to draw integers from the expection.

FAQ:

- Q: What if I do not know the concentration of halos?

  A: use 5~7 is usually good enough. Or compute it from mass from some formula
     like halotools [1], or

     https://nbodykit.readthedocs.io/en/latest/api/_autosummary/nbodykit.transform.html#nbodykit.transform.HaloConcentration

- Q: What if I do not know the virial radius of halos?

  A: https://nbodykit.readthedocs.io/en/latest/api/_autosummary/nbodykit.transform.html#nbodykit.transform.HaloRadius
     but note that function returns proper Mpc/h. So usually you want to modify this to comoving by divide by scaling factor.

- Q: What if I do not know the velocity dispersion of halos?

  A: https://nbodykit.readthedocs.io/en/latest/api/_autosummary/nbodykit.transform.html#nbodykit.transform.HaloSigma (may be a broken link)
  A: https://nbodykit.readthedocs.io/en/latest/api/_autosummary/nbodykit.transform.html#nbodykit.transform.HaloVelocityDispersion


.. [1] :: https://github.com/astropy/halotools/blob/v0.6/halotools/empirical_models/phase_space_models/analytic_models/satellites/nfw/conc_mass/dutton_maccio14.py#L11