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# stub function definition file for docstring parsing
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[docs]def msuvbinflag(binnedvis, method='radial_per_plane', nsigma=5.0, doplot=False):
r"""
An algorithm to identify outliers in the UV plane via the UV grid generated by msuvbin.
Both msuvbin and msuvbinflag tasks are experimental
[`Description`_] [`Examples`_] [`Development`_] [`Details`_]
Parameters
- binnedvis_ (string) - Name of input binned MS from msuvbin task.
- method_ (string='radial_per_plane') - Flagging algorithm (radial_per_plane, radial_mean_annular)
.. raw:: html
<details><summary><i> method = radial_per_plane </i></summary>
- nsigma_ (double=5.0) - nsigma threshold above which to flag
.. raw:: html
</details>
.. raw:: html
<details><summary><i> method = radial_mean_annular </i></summary>
- nsigma_ (double=5.0) - nsigma threshold above which to flag
.. raw:: html
</details>
- doplot_ (bool=False) -
Generate plots of the radial profiles, useful for debugging. Warning : This can severely impact runtime performance.
.. _Description:
Description
.. warning:: **WARNING**: This task is currently experimental.
**msuvbinflag** An algorithm to identify outliers in the UV plane
through a defined uniform grid by msuvbin. Both msuvbin and msuvbinflag
tasks are experimental. Msuvbinflag is automatic flagging algorithm for
the identification of Radio Frequency Interference (RFI) in the UV plane
for experimental purpose. The visibilities in input CASA Measurements Set (MS)
is first gridded into an uniformed UV plane with msuvbin task.
Then the significant outliers are computed for entire UV grid based on
the criterional settings configurable by users for three method options:
radian, diffential and regional mean.
After computing flags for each visibility in each uniformed UV bin,
the visibilities are transformed reverslity back to original order in the
MS file with flagging information. The first msuvbinflag release version
is for NRAO internal use to evaluate the speed and numarical
analysis performance.
.. rubric:: Parameter descriptions
*vis*
Name of input visibility file
*field*
Field name list; note that this position will define the phase
center of the output uv grid
*spw*
Spectral window selection
*taql*
TaQl expression for data selection (see `Data Selection in a
Measurement
Set <../../notebooks/visibility_data_selection.ipynb>`__ or `CASAcore NOTE
199: Table Query
Language <https://casacore.github.io/casacore-notes/199.html>`__ for
more information)
*outvis*
Name of output grid
*phasecenter*
Phase center of the grid, to be used when the phase center of the
selected field is not the desired output phase center.
Example: phasecenter='J2000 18h03m04 -20d00m45.1'
*nx*
Number of pixels along the x axis of the grid. Default: 1000
*ny*
Number of pixels along the y axis of the grid. Default: 1000
*cell*
Cellsize of the grid (given in sky units). Default: '1arcsec'
*ncorr*
Number of correlation/polarization plane in uv grid (allowed 1, 2,
4). For example, if the input data set has the correlations RR and
LL, and *ncorr* =1, then the output uv grid will be written as
Stokes I. If *ncorr=* 2, then the output grid will have both the
RR and LL correlations. Default: 1
*nchan*
Number of spectral channels in the output uv grid. Default: 1
*fstart*
Frequency of the first channel. Default: '1GHz' (the user needs to
give a useful input here)
*fstep*
Width of spectral channel. Default: '1kHz'
*wproject*
Do wprojection correction while gridding. Default: False
*memfrac*
Controls how much of computer's memory is available for gridding.
Default=0.5
.. _Examples:
Examples
.. _Development:
Development
No additional development details
.. _Details:
Parameter Details
Detailed descriptions of each function parameter
.. _binnedvis:
| ``binnedvis (string)`` - Name of input binned visibility data (MS) (the output of the msuvbin task).
| default: none;
| example: binnedvis='SNR_binnedvis.ms'
.. _method:
| ``method (string='radial_per_plane')`` - There are currently two algorithm options to identify outliers in the UV domain: radial_per_plane, radial_mean_annular
| radial_per_plane: This algorithm works independently
| on each plane (channel, polarization) of the binned ms. A mean radial profile is
| generated by doing a weighted average of all data at a given
| UV-radius. A polynomial is fit to the radially averaged
| profile. All the binned UV points that are larger than the
| nsigma threshold are flagged. The threshold is calculated as :
| originalValue[u,v] > radialfitValue[r]+nsigma*rms
| where (u,v) are the UV coordinates, r is the radial distance from the
| center, and rms is the rms of the radial profile at radius r.
| radial_mean_annular: This algorithm combines all the planes in the
| binned MS on to a single UV grid. This combined grid is then
| divided into annular circles from 0 through the maximum UV radius
| in log-spaced intervals. A radial profile is constructed by
| calculating the median values within each annulus, as well as
| the median absolute deviation scaled to the standard deviation.
| Similar to the radial_per_plane method, each plane is then individually
| treated, and a point in the UV plane is flagged if it is greater than
| the nsigma threshold. The threshold is calculated as :
| originalValue[u,v] > radiatValue[n] + nsigma*rms[n]
| where (u,v) are the UV coordinates, and n is the nth annulus.
|
| default: 'radial_per_plane'
| example: method='radial_mean_annular'
.. _nsigma:
| ``nsigma (double=5.0)`` - User defined nsigma value for flagging.
| The default value is 5.
.. _doplot:
| ``doplot (bool=False)`` - Generate plots of the radial profiles calculated prior to flagging. This can be useful to
| debug the performance of the algorithm, however it can severely impact runtime performance.
| In general you do not need to turn this option on.
| The default value is False.
"""
pass