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shear_xi module
Compute the likelihood of a tomographic shear correlation function data set
Name: shear_xi
File: cosmosis-standard-library/likelihood/shear_xi/xipm_like_interface.py
Version: 1.0
Author(s):
- Niall Maccrann
URL:
Cite:
Rules:
Assumptions:
- Gaussian likelihood of shear xi
- Redshift distribution used correctly matches tomographic bins
Explanation
DEPRECATED: This module is not recommended for use any more; use the 2pt_like likelihood instead.
Several surveys are measuring the cosmic shear 2-pt correlation functions xi_+(theta)
and xi_minus(theta) of the gravitational lensing in tomographic redshift bins.
This module calculates the likelihood of theoretical xi(theta) values
values given a data set. It assumes a simple Gaussian likelihood, so the only
complexities are:
selecting exactly which data to use - angular ranges, whether to use xi_minus
if the covariance matrix came from simulations this
adds noise to the covariance matrix - this the number of sims can be set
##Parameters
These parameters can be set in the module's section in the ini parameter file.
If no default is specified then the parameter is required.
| Parameter | Description |
|---|---|
| data_file | string, file containing the data vector. Each row should be one angle, and then the ordering for e.g. three bins is: xip(0,1) xip(0,2) xip(1,1) xip(1,2) xip(2,2) xim(0,0) xim(0,1) xim(0,2) xim(1,1) xim(1,2) xim(2,2) |
| covmat_file | string, file containing the covariance matrix, either text file or numpy npy file. Ordering goes down the columns of the data vector first. |
| n_z_bins | integer, number of redshift bins to use |
| cov_num_rlzn | integer; default=0, number of realizations to assume for covariance simulations. Zero means no simulation errors. |
| plus_only | boolean; default=False, whether to use only xi+ and ignore xi- |
| theta_mins | string; default=empty, Comma separated minimum angles in arcmin for the different bin pairs |
| theta_maxs | string; default=empty, Comma separated maximum angles in arcmin for the different bin pairs |
##Inputs
These parameters and data are inputs to the module, either supplied as parameters by the sampler or computed by some previous module. They are loaded from the data block.
| Section | Parameter | Description |
|---|---|---|
| shear_xi | theta | 1D real array, theta values of theory correlation functions |
| xi_plus_i_j | xi_plus meausurements for i,j=(1..n_z_bins) | |
| xi_minus_i_j | xi_minus meausurements for i,j=(1..n_z_bins) |
##Outputs
These parameters and data are computed as outputs from the module
| Section | Parameter | Description |
|---|---|---|
| likelihoods | xipm_like | real, likelihood of supplied theory correlation functions |
Updated