dsigma.precompute module
Module for pre-computing lensing results.
- dsigma.precompute.mean_photo_z_offset(z_l, table_c, cosmology, weighting=- 2, lens_source_cut=0)
Calculate the mean offset of source photometric redshifts.
- Parameters
- z_lfloat or numpy.ndarray
Redshift(s) of the lens.
- table_castropy.table.Table, optional
Photometric redshift calibration catalog.
- cosmologyastropy.cosmology
Cosmology to assume for calculations.
- weightingfloat, optional
The exponent of weighting of each lens-source pair by the critical surface density. A natural choice is -2 which minimizes shape noise. Default is -2.
- lens_source_cutNone, float or numpy.ndarray, optional
Determine the lens-source redshift separation cut. If None, no cut is applied. If a float, determines the minimum redshift separation between lens and source redshift for lens-source pairs to be used. If an array, it has to be the same length as the source table and determines the maximum lens redshift for a lens-source pair to be used. Default is 0.
- Returns
- dzfloat or numpy.ndarray
The mean source redshift offset for the lens redshift(s).
- dsigma.precompute.photo_z_dilution_factor(z_l, table_c, cosmology, weighting=- 2, lens_source_cut=0)
Calculate the photo-z delta sigma bias as a function of lens redshift.
- Parameters
- z_lfloat or numpy.ndarray
Redshift(s) of the lens.
- table_castropy.table.Table
Photometric redshift calibration catalog.
- cosmologyastropy.cosmology
Cosmology to assume for calculations.
- weightingfloat, optional
The exponent of weighting of each lens-source pair by the critical surface density. A natural choice is -2 which minimizes shape noise. Default is -2.
- lens_source_cutNone, float or numpy.ndarray, optional
Determine the lens-source redshift separation cut. If None, no cut is applied. If a float, determines the minimum redshift separation between lens and source redshift for lens-source pairs to be used. If an array, it has to be the same length as the source table and determines the maximum lens redshift for a lens-source pair to be used. Default is 0.
- Returns
- f_biasfloat or numpy.ndarray
The photo-z bias factor, f_bias, for the lens redshift(s).
- dsigma.precompute.precompute(table_l, table_s, bins, table_c=None, table_n=None, cosmology=FlatLambdaCDM(H0=100.0 km / (Mpc s), Om0=0.3, Tcmb0=0.0 K, Neff=3.04, m_nu=None, Ob0=None), comoving=True, weighting=-2, lens_source_cut=0, nside=256, n_jobs=1, progress_bar=False)
For all lenses in the catalog, precompute the lensing statistics.
- Parameters
- table_lastropy.table.Table
Catalog of lenses.
- table_sastropy.table.Table
Catalog of sources.
- binsnumpy.ndarray or u.quantity.Quantity
Bins in radius to use for the stacking. If a numpy array, bins are assumed to be in Mpc. If an astropy quantity, one can pass both length units, e.g. kpc and Mpc, as well as angular units, i.e. deg and rad.
- table_castropy.table.Table, optional
Additional photometric redshift calibration catalog. If provided, this will be used to statistically correct the photometric source redshifts and critical surface densities. Default is None.
- table_nastropy.table.Table, optional
Source redshift distributions. If provided, this will be used to compute mean source redshifts and critical surface densities. These mean quantities would be used instead the individual photometric redshift estimates. Default is None.
- cosmologyastropy.cosmology, optional
Cosmology to assume for calculations. Default is a flat LambdaCDM cosmology with h=1 and Om0=0.3.
- comovingboolean, optional
Whether to use comoving or physical quantities for radial bins (if given in physical units) and the excess surface density. Default is True.
- weightingfloat, optional
The exponent of weighting of each lens-source pair by the critical surface density. A natural choice is -2 which minimizes shape noise. Default is -2.
- lens_source_cutNone, float or numpy.ndarray, optional
Determine the lens-source redshift separation cut. If None, no cut is applied. If a float, determines the minimum redshift separation between lens and source redshift for lens-source pairs to be used. If an array, it has to be the same length as the source table and determines the maximum lens redshift for a lens-source pair to be used. Default is 0.
- nsideint, optional
dsigma uses pixelization to group nearby lenses together and process them simultaneously. This parameter determines the number of pixels. It has to be a power of 2. May impact performance. Default is 256.
- n_jobsint, optional
Number of jobs to run at the same time. Default is 1.
- progress_barboolean, option
Whether to show a progress bar for the main loop over lens pixels. Default is False.
- Returns
- table_lastropy.table.Table
Lens catalog with the pre-computation results attached to the table.
- Raises
- ValueError
If there are problems in the input.