#
# stub function definition file for docstring parsing
#
[docs]def uvcontsub3(vis, fitspw='', combine='', fitorder=0, field='', spw='', scan='', intent='', correlation='', observation=''):
r"""
An experimental clone of uvcontsub
[`Description`_] [`Examples`_] [`Development`_] [`Details`_]
Parameters
- vis_ (string)
- fitspw_ (string='')
- combine_ (string='')
- fitorder_ (int=0)
- field_ ({string, stringArray, int, intArray}='')
- spw_ (string='')
- scan_ (string='')
- intent_ (string='')
- correlation_ ({string, stringArray}='')
- observation_ ({string, int}='')
.. _Description:
Description
.. warning:: **ALERT: uvcontsub3** is an experimental task and will
eventually replace the current **uvcontsub** code with the
goal of taking less time and temporary disk space.
**uvcontsub3** is a task to perform continuum fitting and
subtraction in the uv plane
This task estimates the continuum emission by fitting
polynomials to the real and imaginary parts of the spectral
windows and channels selected by *fitspw*. This fit represents
a model of the continuum in all channels. The fitted continuum
spectrum is subtracted from all channels selected in *spw*, and
the result (presumably only line emission) is stored in a new
MS that is always called vis + ".contsub". If an MS with the
output name already exists, it will be overwritten.
**uvcontsub3** will read from the CORRECTED_DATA column
of *vis* if it is present, or DATA if it is not. Whichever
column is read is presumed to have already been calibrated.
.. note::
**WARNING:** Strictly speaking, the **uvcontsub3** model
is only a good representation of the continuum at the
phase center. Residuals may be visible for sources far
away and one may try **imcontsub** in the image domain
for improved results.
.. note:: **WARNING** **:** * fitorders* > 1 are strongly
discouraged because high order polynomials have more
flexibility, may absorb line emission, and tend to go wild
at the edges of *fitspw*, which is not what you
want. default: *0* (constant)
.. rubric:: Parameter descriptions
*vis*
Name of input MS. Output goes to vis + ".contsub" (will be
overwritten if already exists)
*fitspw*
Selection of spectral windows and channels to use in the fit for
the continuum, using general `MS selection
syntax <../../notebooks/visibility_data_selection.ipynb>`__ for
spectral windows, e.g. in spw:chan format (spw ids are required
but '\*' can be used) or as frequencies. See the note
under *combine*. default: *fitspw=''* (all)
.. warning:: **WARNING:** The *fitspw* selection is based on the channel
numbers in the uv-data of the input MS file, which are most
likely different from the channel numbers in the image plane
after running **tclean**.
*combine*
Continuum solutions will by default break at scan, field, and spw
boundaries. To allow solutions across spw boundaries, *combine*
can be set to '*spw*'. '*combine*' must include *'spw'* if spw
contains spws that are not in *fitspw*! default: '' which is that
solutions will break at scan, field, and spw
.. warning:: **WARNING:** uvcontsub3 (deliberately) does not
support combination by anything except '*spw*'. Other
combination options supported in uvcontsub, '*scan*',
or '*spw*', are not supported in this experimental
uvcontsub3 version. Also, combination by spw is only
expected to work correctly for spws with the same
number of channels.
*fitorder*
Polynomial order for the fits of the continuum w.r.t.
frequency. *fitorders* > 1 are strongly discouraged because high
order polynomials have more flexibility, may
absorb line emission, and tend to go wild at the edges
of *fitspw*, which is not what you want. default: *0* (constant)
*field*
Field selection for
continuum estimation and subtraction. The estimation and
subtraction is done for each selected field separately in turn.
default: '' (all fields).
*spw*
Optional per spectral window selection of channels to include in
the output. See the note under *combine*. The sub-MS output
spectral windows will be renumbered to start from 0, as
in **split**. default: '' (all spws)
*scan*
Scan id selection. default: '' (all scans)
*intent*
Selection by scan intent. default: '' (all intents)
*correlation*
Selection by correlation. default: '' (all correlations)
(polarization products)
*observation*
Selection by observation id. default: '' (all obs ids)
.. _Examples:
Examples
**Example 1:**
Subtract the continuum of channels 10~100 and 300~350 in spw 0
(assuming that the line is in channels 101~299). Note that we also
exclude edge channels, e.g. the first 9 channels. We use a
fitorder of 0 (default).
::
uvcontsub3(vis='myMS.ms',fitspw='0:10~100;300~350')
.. _Development:
Development
No additional development details
.. _Details:
Parameter Details
Detailed descriptions of each function parameter
.. _vis:
| ``vis (string)`` - Name of input MS. Output goes to vis + ".contsub"
.. _fitspw:
| ``fitspw (string='')`` - Spectral window:channel selection for fitting the continuum
.. _combine:
| ``combine (string='')`` - Data axes to combine for the continuum estimation (none ('') or spw)
.. _fitorder:
| ``fitorder (int=0)`` - Polynomial order for the fits
.. _field:
| ``field ({string, stringArray, int, intArray}='')`` - Select field(s) using id(s) or name(s)
.. _spw:
| ``spw (string='')`` - Spectral window selection for output
.. _scan:
| ``scan (string='')`` - Select data by scan numbers
.. _intent:
| ``intent (string='')`` - Select data by scan intents
.. _correlation:
| ``correlation ({string, stringArray}='')`` - Select correlations
.. _observation:
| ``observation ({string, int}='')`` - Select by observation ID(s)
"""
pass