The vimos_ima_bias recipe
===============================================================

.. data:: vimos_ima_bias

Synopsis
--------

Bias combination for imaging

Description
-----------

vimos_ima_bias -- VIMOS bias combine recipe.


Combine a list of bias frames into a mean bias frame. Optionally compare 
the output frame to a reference bias frame

The program accepts the following files in the SOF:

    Tag                   Description
    BIAS                  A list of raw bias images
    REFERENCE_BIAS        Optional reference bias frame
If no reference bias frame is made available, then no comparison will
be done. This means there will be no output difference image or stats table. 

Constructor
-----------

.. method:: cpl.Recipe("vimos_ima_bias")
   :noindex:

   Create an object for the recipe vimos_ima_bias.

::

   import cpl
   vimos_ima_bias = cpl.Recipe("vimos_ima_bias")

Parameters
----------

.. py:attribute:: vimos_ima_bias.param.combtype

    Combination algorithm (str; default: 'median') [default="median"].
.. py:attribute:: vimos_ima_bias.param.xrej

    True if using extra rejection cycle (bool; default: True) [default=True].
.. py:attribute:: vimos_ima_bias.param.thresh

    Rejection threshold in sigma above background (float; default: 5.0) [default=5.0].
.. py:attribute:: vimos_ima_bias.param.ncells

    Number of cells for diff image stats (int; default: 64) [default=64].
.. py:attribute:: vimos_ima_bias.param.prettynames

    Use pretty output file names? (bool; default: False) [default=False].


The following code snippet shows the default settings for the available 
parameters.

::

   import cpl
   vimos_ima_bias = cpl.Recipe("vimos_ima_bias")

   vimos_ima_bias.param.combtype = "median"
   vimos_ima_bias.param.xrej = True
   vimos_ima_bias.param.thresh = 5.0
   vimos_ima_bias.param.ncells = 64
   vimos_ima_bias.param.prettynames = False


You may also set or overwrite some or all parameters by the recipe 
parameter `param`, as shown in the following example:

::

   import cpl
   vimos_ima_bias = cpl.Recipe("vimos_ima_bias")
   [...]
   res = vimos_ima_bias( ..., param = {"combtype":"median", "xrej":True})


.. seealso:: `cpl.Recipe <https://packages.python.org/python-cpl/recipe.html>`_
   for more information about the recipe object.

Bug reports
-----------

Please report any problems to `Jim Lewis <jrl@ast.cam.ac.uk>`_. Alternatively, you may 
send a report to the `ESO User Support Department <usd-help@eso.org>`_.

Copyright
---------

This file is part of the VIMOS Instrument Pipeline
Copyright (C) 2019 European Southern Observatory

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, 
MA  02111-1307  USA

.. codeauthor:: Jim Lewis <jrl@ast.cam.ac.uk>