|

cwb_xtalk
~~~~~~~~~~~~~~

This page provides a description of the cwb_xtalk command.

|
| **Info**
|
| The xTalk catalog files contain the overlapping coefficients between WDM pixels and are used by 
| wavelet-packet to reconstruct the signal using pixels at different resolution levels.


|
| **Usage**
|
|  This command generates the xtalk catalog used in the Multi Resolution Analysis.
|
| **Syntax**
|

 - ``cwb_xtalk`` (without arguments)
    Prints help
 - ``cwb_xtalk low_res_level high_res_level iNu precision``
    It generates the xtalk catalog

|
| **Further information**
|
  The following options can be passed to cwb_xtalk:

 .. code-block:: bash

    action =    low_res_level     :  it corresponds to the lower resolution level.
                                     The level is selected as 2^low_res_level

                high_res_level    :  it corresponds to the higher resolution level. 
                                     The level is selected as 2^high_res_level

                iNu               :  (optional, by default set to 4) it corresponds to the sharpness 
                                     of the 'edge' of the basis function in Fourier domain
     
                precision         :  (optional, by default set to 10) it defines the filter length 
                                     by truncation error quantified by P = -log10(1 - norm_of_filter)

|
| **Examples**
|

 - The following command line generates the Overlap Catalog file OverlapCatalog-lLev3-hLev8-iNu4-P10.bin with low- and high-resolution layers equal to 8 and 256, respectively:
    ``cwb_xtalk 3 8``


.. note::
   The overlap catalog files used for the Second Observational run O2 searches is:

    - BurstLF, BurstHF, BBH, IMBHB: 
       OverlapCatalog16-1024.bin (is equal to the file OverlapCatalog-ilLev4-hLev10-iNu4-P10.xbin)

       The file is generate with the following command: ``cwb_xtalk 4 10 4 10``

    - BurstLD: 
       OverlapCatalog-ilLev6-hLev12-iNu6-P10.xbin 

       The file is generate with the following command: ``cwb_xtalk 6 12 6 10``

   For the Third Observational run O3 searches we will plan to use:

    - BurstLF, BurstHF, BBH, IMBHB: 
       OverlapCatalog-ilLev4-hLev10-iNu6-P10.xbin (almost equivalent to OverlapCatalog-ilLev4-hLev10-iNu4-P10.xbin)

       The file is generate with the following command: ``cwb_xtalk 4 10 6 10``

    - BurstLD: 
       OverlapCatalog-ilLev6-hLev12-iNu6-P10.xbin

       The file is generate with the following command: ``cwb_xtalk 6 12 6 10``


.. _cwb-xtalk-owncloud:

.. attention::
   The generation of the catalog files may takes a while. We suggest to download the files from the public directory `WDMxTalk-Catalogs <https://owncloud.ego-gw.it/index.php/s/I4r2Q2oyi4fLWWw>`_

   The line command to download **OverlapCatalog16-1024.bin** is:

   ``wget https://owncloud.ego-gw.it/index.php/s/qHBlJIOhpC6K9U3/download -O OverlapCatalog16-1024.bin``

   The line command to download **OverlapCatalog-ilLev6-hLev12-iNu6-P10.xbin** is:

   ``wget https://owncloud.ego-gw.it/index.php/s/cPsA5THoEUwLMXn/download -O OverlapCatalog-ilLev6-hLev12-iNu6-P10.xbin``