#
# stub function definition file for docstring parsing
#
[docs]def uvmodelfit(vis, field='', spw='', selectdata=True, timerange='', uvrange='', antenna='', scan='', msselect='', niter=5, comptype='P', sourcepar=[1.0, 0.0, 0.0], varypar=[''], outfile=''):
r"""
Fit a single component source model to the uv data
[`Description`_] [`Examples`_] [`Development`_] [`Details`_]
Parameters
- vis_ (string) - Name of input visibility file
- field_ (string='') - Select field using field id(s) or field name(s)
- spw_ (string='') - Select spectral window/channels
- selectdata_ (bool=True) - Other data selection parameters
.. raw:: html
<details><summary><i> selectdata = True </i></summary>
- timerange_ (string='') - Select data based on time range
- uvrange_ (variant='') - Select data within uvrange (default units meters)
- antenna_ (string='') - Select data based on antenna/baseline
- scan_ (string='') - Scan number range
- msselect_ (string='') - Optional complex data selection (ignore for now)
.. raw:: html
</details>
- niter_ (int=5) - Number of fitting iterations to execute
- comptype_ (string='P') - component model type: P(oint), G(aussian), or D(isk)
- sourcepar_ (doubleArray=[1.0, 0.0, 0.0]) - Starting guess for component parameters (3 values for type P, 5 for G and D)
- varypar_ (boolArray=['']) - Control which parameters to let vary in the fit
- outfile_ (string='') - Optional output component list table
.. _Description:
Description
Fit a single component source model to the uv-data. Three
models are available: P=point; G=Gaussian; D=Disk. Fitting
parameters can be held fixed. The results are given in the CASA
log and placed in a components file. More information can be found
about uvmodelfit `here <../../notebooks/uv_manipulation.ipynb>`__ .
.. note:: **INFO:** The Nordic ALMA Regional Center Node has developed
tools for fitting multiple components of any shape to the
visibilities. Their versatile
uvmultifit [1]_ package is provided on their
`software tools <https://www.oso.nordic-alma.se/software-tools.php>`__
page.
.. rubric:: Parameter descriptions
*vis*
Name of input visibility file. Default: none. Examples:
vis='ngc5921.ms'
*field*
Select data based on field id(s) or name(s). Default: '' (all).
Examples: field='1'; field='0~2', field IDs inclusive from 0 to 2;
field='3C*', all field names starting with 3C
*spw*
Select data based on spectral window. Default: '' (all). Examples:
spw='1'; spw='<2' #spectral windows less than 2; spw='>1',
spectral windows greater than 1
*selectdata*
Select a subset of the visibility using MSSelection. Default:
False. Examples: selectdata=True
*timerange*
Select data based on time range. Default = '' (all). Examples:
timerange = 'YYYY/MM/DD/hh:mm:ss~YYYY/MM/DD/hh:mm:ss'
.. note:: NOTE: YYYY/MM/DD can be dropped as needed.
Further examples:* timerange='09:14:0~09:54:0'* yields the quoted
time range; *timerange='09:44:00'* yields data within one
integration of the specified time; *timerange='>10:24:00'*
yields data after the specified time;
*timerange='09:44:00+00:13:00'* yields data 13 minutes after the
specified time
*uvrange*
Select data within uvrange (default units kilo-lambda). Default:
'' (all). Examples: uvrange='0~1000klambda', uvrange from 0-1000
kilo-lambda; uvrange='>4klambda', uvranges greater than 4 kilo
lambda; uvrange='0~1000km', uvrange in kilometers
*antenna*
Select data based on antenna/baseline. Default: '' (all).
Examples: antenna='5&6', baseline 5-6; antenna='5&6;7&8',
baselines 5-6 and 7-8; antenna='5', all baselines with antenna 5;
antenna='5,6', all baselines with antennas 5 and 6
*scan*
Select data based on scan number. Default: '' (all). Examples:
scan='>3'
*msselect*
Optional data selection (field,spw,time,etc). Default:'' means
select all. Examples: msselect='FIELD_ID==0'; msselect='FIELD_ID
IN [0,1,2]' means select fields 0,1 and 2; msselect='FIELD_ID <=
1' means select fields 0, 1; msselect='FIELD_ID==0 && ANTENNA1 IN
[0] && ANTENNA2 IN [2:26]' means select field 0 and antennas 0 to
26, except antenna 1. Other msselect fields are: 'DATA_DESC_ID',
'SPECTRAL_WINDOW_ID', 'POLARIZATION_ID', 'SCAN_NUMBER', 'TIME',
'UVW'.
*niter*
Number of fitting iterations to execute. Default: 5. Examples:
niter=20
*comptype*
Component model type. Default: 'P'. Options: 'P' (point source),
'G' (elliptical gaussian), 'D' (elliptical disk)
*sourcepar*
Starting guess for component parameters. Default: [1,0,0] (for
comptype='P').
If comptype = 'P', then sourcepar = [flux,xoff,yoff], where flux =
flux (Jy), xoff = offset east (arcsec), yoff = offset north
(arcsec).
If comptype = 'G' or 'D', then sourcepar =
[flux,xoff,yoff,majax,axrat,pos], where majax = FWHM along the
major axis (arcsec), axrat < 1 is the ratio of minor to major
axis, pos = position angle (deg)
*varypar*
Control which parameters to let vary in the fit. Default: [ ] (all
vary). Examples: varypar=[False,True,True]
**Examples with comptype, sourcepar, and varypar**
Fit a point: comptype = 'P', sourcepar = [0.4,0.2,-0.3], varypar =
[True,True,True]
Fit a circular Gaussian: comptype = 'G', sourcepar =
[1.4,0.3,-0.2,0.3, 1, 0], varypar = [ True , True , True , True ,
False, False]
*outfile*
Optional output component list table. Default: ''. Examples:
outfile='componentlist.cl'
How to get the output values:
::
cl.open('componentlist.cl') #open the componentlist 'componentlist.cl'
fit = cl.getcomponent(0) #stores component informationof the first component
fit #to see the list
flux = fit['flux']['value'] #to store the I,Q,U,V, flux
print flux
ra = fit['shape']['direction']['m0']['value']
dec =fit['shape']['direction']['m1']['value']
print ra, dec
bmaj = fit['shape']['majoraxis']['value'] #to get major axis
bmin = fit['shape']['minoraxis']['value'] #to get minor axis
Bibliography
.. [1] Marti-Vidal et al. 2014, A&A 563, 136 `arXiv:1401.4984 <http://arxiv.org/abs/1401.4984>`__
.. _Examples:
Examples
More information on **uvmodelfit** can be found
`here <../../notebooks/uv_manipulation.ipynb>`__.
::
# Note: It's best to channel average the data if there are many channels before running a modelfit
split('ngc5921.ms','1445+099_avg.ms', datacolumn='corrected',field='1445*',width='63')
# Initial guess is that it's close to the phase center and has a flux of 2.0 (a priori we know it's 2.47)
uvmodelfit('1445+099_avg.ms', # use averaged data
niter=5, # Do 5 iterations
comptype='P', # P=Point source, G=Gaussian, D=Disk
sourcepar=[2.0,.1,.1], # Source parameters for a point source
spw='0',
outfile='gcal.cl') # Output component list file
.. _Development:
Development
No additional development details
.. _Details:
Parameter Details
Detailed descriptions of each function parameter
.. _vis:
| ``vis (string)`` - Name of input visibility file
.. _field:
| ``field (string='')`` - Select field using field id(s) or field name(s)
.. _spw:
| ``spw (string='')`` - Select spectral window/channels
.. _selectdata:
| ``selectdata (bool=True)`` - Other data selection parameters
.. _timerange:
| ``timerange (string='')`` - Select data based on time range
.. _uvrange:
| ``uvrange (variant='')`` - Select data within uvrange (default units meters)
.. _antenna:
| ``antenna (string='')`` - Select data based on antenna/baseline
.. _scan:
| ``scan (string='')`` - Scan number range
.. _msselect:
| ``msselect (string='')`` - Optional complex data selection (ignore for now)
.. _niter:
| ``niter (int=5)`` - Number of fitting iterations to execute
.. _comptype:
| ``comptype (string='P')`` - component model type: P(oint), G(aussian), or D(isk)
.. _sourcepar:
| ``sourcepar (doubleArray=[1.0, 0.0, 0.0])`` - Starting guess for component parameters (3 values for type P, 5 for G and D)
.. _varypar:
| ``varypar (boolArray=[''])`` - Control which parameters to let vary in the fit
.. _outfile:
| ``outfile (string='')`` - Optional output component list table
"""
pass