additive_systematic
================================================

Model additive systematic errors for HSC cosmic shear analysis

+-------------+--------------------------------------------------------------+
| File        | likelihood/hsc_cosmic_shear/additive_systematic/sys_model.py |
+-------------+--------------------------------------------------------------+
| Attribution | Roohi Dalal                                                  |
+-------------+--------------------------------------------------------------+
|             | Xiangchong Li                                                |
+-------------+--------------------------------------------------------------+
|             | HSC Collaboration                                            |
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| URL         |                                                              |
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| Citations   | https://arxiv.org/abs/2304.00701                             |
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This module models additive systematic errors for the Hyper Suprime-Cam
(HSC) cosmic shear analysis. It implements parametric models for
systematics that are added to the theoretical cosmic shear correlation
functions to account for observational effects that are not captured
by the standard cosmological model.


Assumptions
-----------

 - Additive systematics can be modeled with simple parametric forms
 - Systematics are additive to the cosmic shear signal



Setup Parameters
----------------

.. list-table::
   :header-rows: 1

   * - Name
     - Type
     - Default
     - Description

   * - theta_min
     - real
     - 6.0
     - Minimum angular scale to include (arcmin)
   * - theta_max
     - real
     - 200.0
     - Maximum angular scale to include (arcmin)
   * - model_type
     - str
     - 
     - Type of systematic model to use ('systematics' or 'pca')
   * - psf_file
     - str
     - 
     - Path to file containing PSF systematic matrices (required for model_type='systematics')
   * - nzs
     - int
     - 
     - Number of redshift bins (required for model_type='systematics')
   * - tfile
     - str
     - 
     - Optional transformation file for parameter space (for model_type='systematics')


Input values
----------------

.. list-table::
   :header-rows: 1

   * - Section
     - Name
     - Type
     - Default
     - Description

   * - shear_xi_plus
     - nbin_a
     - int
     - 
     - Number of redshift bins for first shear measurement
   * - 
     - nbin_b
     - int
     - 
     - Number of redshift bins for second shear measurement
   * - 
     - theta
     - real 1d
     - 
     - Angular separation values
   * - psf_systematics_parameters
     - psf_cor{i}_z{j}
     - real
     - 
     - PSF correlation systematic parameters for component i, redshift bin j
   * - 
     - psf_c1_z{j}
     - real
     - 
     - PSF additive bias c1 parameter for redshift bin j
   * - 
     - psf_c2_z{j}
     - real
     - 
     - PSF additive bias c2 parameter for redshift bin j


Output values
----------------


.. list-table:: Output values
   :header-rows: 1

   * - Section
     - Name
     - Type
     - Description

   * - shear_xi_plus
     - theta
     - real 1d
     - Modified angular separation values (trimmed to theta_min/theta_max range)