The fors_photometry recipe
===============================================================

.. data:: fors_photometry

Synopsis
--------

Compute corrected flatfield

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

Input files
^^^^^^^^^^^^
::

  DO category:               Type:       Explanation:             Number:
  PHOT_TABLE                 FITS table  Expected extinction params  1
  ALIGNED_PHOT               FITS table  Photometry                  1+
  MASTER_SKY_FLAT_IMG        FITS image  Master flat field           1

Output files
^^^^^^^^^^^^
::

  DO category:               Data type:  Explanation:
  PHOT_COEFF_TABLE           FITS image  Observed extinction coefficients
  CORRECTION_MAP             FITS image  Correction map (magnitude)
  CORRECTION_FACTOR          FITS image  Correction map (flux)
  MASTER_FLAT_IMG            FITS image  Corrected master flat field

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

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

   Create an object for the recipe fors_photometry.

::

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

Parameters
----------

.. py:attribute:: fors_photometry.param.fitz

    Fit zeropoint (bool; default: True) [default=True].
.. py:attribute:: fors_photometry.param.fit_all_mag

    Always fit star magnitudes (bool; default: False) [default=False].
.. py:attribute:: fors_photometry.param.fite

    Fit atmospheric extinctions (str; default: 'pernight') [default="pernight"].
.. py:attribute:: fors_photometry.param.fitc

    Fit color correction term (bool; default: False) [default=False].
.. py:attribute:: fors_photometry.param.use_all_stars

    Use also non-standard stars to fit polynomial f (bool; default: False) [default=False].
.. py:attribute:: fors_photometry.param.degreef1

    FLatfield correction map polynomial degree (x) (int; default: 0) [default=0].
.. py:attribute:: fors_photometry.param.degreef2

    Flatfield correction map polynomial degree (y), or negative for  triangular coefficient matrix (int; default: -1) [default=-1].
.. py:attribute:: fors_photometry.param.degreep

    Extinction/color coupling degree (int; default: 0) [default=0].
.. py:attribute:: fors_photometry.param.mjd_obs_target

    MJD-OBS used to match the raw frame from which EXTINCTION_PER_NIGHT  and PHOT_COEFF inherit MJD-OBS. If negative theMJD-OBS of the first  raw frame isused (float; default: -1.0) [default=-1.0].


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

::

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

   fors_photometry.param.fitz = True
   fors_photometry.param.fit_all_mag = False
   fors_photometry.param.fite = "pernight"
   fors_photometry.param.fitc = False
   fors_photometry.param.use_all_stars = False
   fors_photometry.param.degreef1 = 0
   fors_photometry.param.degreef2 = -1
   fors_photometry.param.degreep = 0
   fors_photometry.param.mjd_obs_target = -1.0


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

::

   import cpl
   fors_photometry = cpl.Recipe("fors_photometry")
   [...]
   res = fors_photometry( ..., param = {"fitz":True, "fit_all_mag":False})


.. 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 `Jonas M. Larsen <usd-help@eso.org>`_. Alternatively, you may 
send a report to the `ESO User Support Department <usd-help@eso.org>`_.

Copyright
---------

This file is currently part of the FORS Instrument Pipeline
Copyright (C) 2002-2011 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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA


.. codeauthor:: Jonas M. Larsen <usd-help@eso.org>