mockFactory

Python implementation of mockFactory, right now populateSimulationHOD is implemented. Use it to make mocks and compute clustering.

Requirements

Python 3.6

numpy

pandas

colossus, for calculating halo concentration

if you want to use clustering module, Corrfunc is required

if you want to use MCMC module, emcee is required

Usage

Initialization

Feel free to change any cosmological parameters in parameters.py

import mockFactory

from mockFactory import MockFactory

You can define input halofile and hod parameters. In this example, "halo_test.dat" in data directory is 1% of MDPL2 simulation halo file at redshift z=0.84. If you don't pass hod params into arguments, default hod will be used.

Halo file should have the first 7 columns as in format: "M200b", "x", "y", "z", "vx", "vy", "vz".

halofile = "../data/halo_test.dat"

hod_params = {'f_max': 0.0919869695747, 'M_min': 6.8*10**12, 'M_cut': 1.45690882049e+12, 
               'sigma_logM':0.640647507034, 'alpha':0.899309153294, 
               'M_1': 1.99576840607e+14}

mockfactory = MockFactory(halofile, boxsize=1000, cvir_fac=1, vbias=0.8, hod_parameters=hod_params)

output should be:

[MockFactory] Reading halo file ../data/halo_test.dat ...
[MockFactory] Done reading halo file, time cost 1.61s ...
MAX HALOMASS 14.652430079305446
MAX HALOMASS 9.478681907362235
[MockFactory] Adjusting position ...
[MockFactory] Done adjusting position ...
[MockFactory] Computing halo concentration ...
[MockFactory] Read 1213430 halos ...
[MockFactory] memory used 92.5774 Mb ...

Populate mock

If you don't pass mock_flnm into the function, it will not write to file.

mockfile = "../data/mock_test.dat"
mock = mockfactory.populateSimulation(mock_flnm = mockfile, verbose=True)

[MockFactory] Begin populateSimulation ...
[MockFactory] Begin _populateCentral ...
number of central is 5105
[MockFactory] Done _populateCentral, time cost 0.10s ...
[MockFactory] Begin _populateSatellite ...
assign position and velocity...
number of satellite is 718
[MockFactory] Done _populateSatellite, time cost 0.14s ...
Writing to file ../data/mock_test.dat ...
[MockFactory] Done populateSimulation, time cost 0.27s ...

The mock has shape of (n_gal, 8), with columns as M_halo, x, y, z, vx, vy, vz, isCentral.

isCentral == 1 means the galaxy is a central galaxy, 0 means satellite galaxy.

mock.shape

(5823, 8)

Clustering

You can compute clustering as follows:

from clustering import Clustering
import numpy as np

rbins = np.logspace(np.log10(0.1), np.log10(70), 21)
cluster = Clustering(rbins)

The input mock should have first 6 columns as x, y, z, vx, vy, vz.