poisson_sample_gal_position module

Script to Poisson-sample the matter density field traced by the p(z) redshift distribution at each map slice in redshift space. Generates a number count of galaxies per Healpix pixel, which is saved as a simple table ‘cat_indices.hdf5’ on disk to then load and assign shear values to in the following ‘compile_cat.py’ script. Repeated over a given number of realisations/iterations.

catalogue_sim.poisson_sample_gal_position.execute_poisson_sampling()

Execute the Poisson sampling routine - load in pipeline parameters from variables file, then apply observation mask and Poisson sample the observed pixels. This process essentially assigns each galaxy in the sample a given Healpix pixel ID - the location on the sky where it is observed. This table is then saved to disk under the ‘cat_products/cat_indices/’ location.

catalogue_sim.poisson_sample_gal_position.poisson_sample_masked_map(expected_numb_dens_map, mask, n_pixels)

Function to poisson sample a given matter field map by returning an integer number count of galaxies per pixel

Parameters

expected_numb_dens_map(arr)

Array of the ‘expected’ number density of galaxies converted from the raw density field

mask(arr)

Healpix map of the given mask used for observation

n_pixels(float)

Number of pixels in the given map

Returns

A Healpix map contaning the per pixel integer number density of galaxies. Pixels that fall outside of the mask are given the hp.UNSEEN value.