The fors_spec_mflat recipe =============================================================== .. data:: fors_spec_mflat Synopsis -------- Computes master spectroscopic flat, removing bias first Description ----------- This recipe is used to subtract the master bias, produced by the recipe fors_bias, from a set of raw flat field frames. The input raw frames are summed, the master bias frame is rescaled accordingly, and subtracted from the result. The overscan regions, if present, are used to compensate for variations of the bias level between master bias and input raw frames. The overscan regions are then trimmed from the result. In the table below the MXU acronym can be alternatively read as MOS and LSS. Input files ^^^^^^^^^^^^ :: DO category: Type: Explanation: Required: SCREEN_FLAT_MXU Raw Raw data frame Y SLIT_LOCATION_MXU Calib Slits positions on CCD Y CURV_COEFF_MXU Calib Slits tracing fits Y DISP_COEFF_MXU Calib Wavelength calibration Y MASTER_BIAS Calib Master bias frame Y Output files ^^^^^^^^^^^^ :: DO category: Data type: Explanation: MASTER_SCREEN_FLAT_MXU FITS image Bias subtracted sum frame Constructor ----------- .. method:: cpl.Recipe("fors_spec_mflat") :noindex: Create an object for the recipe fors_spec_mflat. :: import cpl fors_spec_mflat = cpl.Recipe("fors_spec_mflat") Parameters ---------- .. py:attribute:: fors_spec_mflat.param.smooth_sed Smoothing size for each flat sed (float; default: 0.0) [default=0.0]. .. py:attribute:: fors_spec_mflat.param.stack_method Frames combination method (str; default: 'sum') [default="sum"]. .. py:attribute:: fors_spec_mflat.param.klow Low threshold in ksigma method (float; default: 3.0) [default=3.0]. .. py:attribute:: fors_spec_mflat.param.khigh High threshold in ksigma method (float; default: 3.0) [default=3.0]. .. py:attribute:: fors_spec_mflat.param.kiter Max number of iterations in ksigma method (int; default: 999) [default=999]. .. py:attribute:: fors_spec_mflat.param.nonlinear_level Level above which the detector is not linear (float; default: 50000.0) [default=50000.0]. .. py:attribute:: fors_spec_mflat.param.max_nonlinear_ratio Maximum allowed ratio of non-linear pixels per slit (float; default: 0.2) [default=0.2]. The following code snippet shows the default settings for the available parameters. :: import cpl fors_spec_mflat = cpl.Recipe("fors_spec_mflat") fors_spec_mflat.param.smooth_sed = 0.0 fors_spec_mflat.param.stack_method = "sum" fors_spec_mflat.param.klow = 3.0 fors_spec_mflat.param.khigh = 3.0 fors_spec_mflat.param.kiter = 999 fors_spec_mflat.param.nonlinear_level = 50000.0 fors_spec_mflat.param.max_nonlinear_ratio = 0.2 You may also set or overwrite some or all parameters by the recipe parameter `param`, as shown in the following example: :: import cpl fors_spec_mflat = cpl.Recipe("fors_spec_mflat") [...] res = fors_spec_mflat( ..., param = {"smooth_sed":0.0, "stack_method":"sum"}) .. seealso:: `cpl.Recipe `_ for more information about the recipe object. Bug reports ----------- Please report any problems to `Carlo Izzo `_. Alternatively, you may send a report to the `ESO User Support Department `_. 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:: Carlo Izzo