SIMBIG

Simulation-based Inference of Galaxies

Installation

First set up a new anaconda environment to avoid any package conflicts.

Activate the conda environment and then install the simbig package

# first clone the repo
git clone https://github.com/changhoonhahn/simbig.git

# go to the repo
cd simbig 

# install the package 
pip install -e .

You will also need to set the $QUIJOTE_DIR environment variable. To do this, add the following line

# if you're on tiger
export QUIJOTE_DIR="/projects/QUIJOTE/"

# if you're on flatiron popeye  
export QUIJOTE_DIR="/mnt/home/chahn/ceph/QUIJOTE/"

to your ~/.bashrc file. If you don't know how to do this then just copy paste the following:

# if you're on tiger
echo 'export QUIJOTE_DIR="/projects/QUIJOTE/"' >> ~/.bashrc

# if you're on flatiron popeye  
echo 'export QUIJOTE_DIR="/mnt/home/chahn/ceph/QUIJOTE/"' >> ~/.bashrc

Once you've added the line, don't forget to run

source ~/.bashrc

Setting Up a Conda Environment

On `tiger`

If you're on Princeton's tiger cluster, you don't have to install anaconda. You can load it using

module load anaconda

Afterwards you can create a new conda environment using

conda create -n ENV_NAME_HERE python=3.7 ipython

and following the instructions.

To activate the conda environment you created

conda activate ENV_NAME_HERE

Later, if you want to exist the conda environemtn

conda deactivate

`pySpectrum` installation

If you're interested in calculating the bispectrum, you'll have to install pySpectrum. More specifically, you'll have to install the survey branch of pySpectrum, which includes the latest updates (this will be merged into main branch soon).

To install pySpectrum, activate your conda environment and run:

git clone --single-branch --branch survey https://github.com/changhoonhahn/pySpectrum.git
cd pySpectrum
pip install -e .

Dependencies

The simbig package requires the following python pacakges:

tl;dr Run the following lines after activating the conda environment

conda install -c bccp nbodykit
pip install pymangle
pip install sbi

Generating an HOD catalog for HR Quijote LHC

import numpy as np 
from simbig.halos import Quijote_LHC_HR
from simbig import galaxies as Galaxies

# read in halo catalog 
halos = Quijote_LHC_HR(1, z=0.5)

# get LOWZ HOD parameters
theta_hod = Galaxies.thetahod_lowz_ngc()

# apply HOD 
gals = Galaxies.hodGalaxies(halos, theta_hod, seed=0) 
print(np.array(gals['Position']))

Resources

Details and resources on the original BOSS analysis: https://sites.google.com/view/learningouruniverse/boss-analysis?authuser=0

muntazirabidi/boss-sbi