clearcal

clearcal(vis, field='', spw='', intent='', addmodel=False)[source]

Re-initializes the calibration for a visibility data set

[Description] [Examples] [Development] [Details]

Parameters

vis (path) - Name of input visibility file (MS)
field (string=’’) - Select field using field id(s) or field name(s)
spw (string=’’) - Select spectral window/channels
intent (string=’’) - Select observing intent
addmodel (bool=False) - Add MODEL_DATA scratch column

Description

re-initializes the calibration for a visibility data set

Re-initializes the calibration columns in a MeasurementSet. Specificially, it will set the MODEL_DATA column (if present) to unity in total intensity and zero in polarization, and it will set the CORRECTED_DATA column to the original (observed) DATA in the DATA column. Use the field and spw parameters to select which data to initialize.

If the dataset does not yet have the scratch columns, they will be created (MODEL_DATA only if addmodel=True) and initilized for the whole dataset. In this case, the arguments field, spw, and intent will be ignored.

Parameters

vis

Name of input visibility file.

field

Standard selection of fields using the field id(s) or field name(s).

spw

Standard selection of spectral windows.

Note

NOTE: Multiple channel ranges per spw are not supported in clearcal.

intent

Select observing intent. For example, intent=’*BANDPASS’* selects data labelled with BANDPASS intent.

addmodel

If True, add a MODEL_DATA column along with CORRECTED_DATA column. If False, only the CORRECTED_DATA will be added and reset, model visibilities will then be evaluated when needed. Default is False (i.e., MODEL_DATA column will not be added).

Examples

To reinitialize the CORRECTED_DATA and fill the column with the (original) observed DATA, and in addition also add a MODEL_DATA column that is set to unity in total intensity and zero in polarization:

clearcal(vis='measurementset.ms', spw='0:5~61', addmodel=True)

Note

NOTE: The above will only be done for channels 5 to 61 in spw 0, provided that the scratch columns already existed in the input MeasurementSet. If the scratch columns initially did not exist and are thus added, they will be initialized for the whole data set and the spw parameter will be ignored.

Development: No additional development details

Parameter Details: Detailed descriptions of each function parameter

vis (path) - Name of input visibility file (MS)

Default: none

Example: vis=’ngc5921.ms’

field (string='') - Select field using field id(s) or field name(s)

default: ‘’ (all fields)

Use ‘go listobs’ to obtain the list id’s or
names. If field string is a non-negative integer,
it is assumed a field index,  otherwise, it is
assumed a field name.
Examples:
field=’0~2’; field ids 0,1,2
field=’0,4,5~7’; field ids 0,4,5,6,7
field=’3C286,3C295’; field named 3C286 and
3C295
field = ‘3,4C*’; field id 3, all names
starting with 4C

spw (string='') - Select spectral window/channels

Examples:
spw=’0~2,4’; spectral windows 0,1,2,4 (all
channels)
spw=’<2’;  spectral windows less than 2
(i.e. 0,1)
spw=’0:5~61’; spw 0, channels 5 to 61,
INCLUSIVE
spw=’*:5~61’; all spw with channels 5 to 61
spw=’0,10,3:3~45’; spw 0,10 all channels, spw
3, channels 3 to 45.
spw=’0~2:2~6’; spw 0,1,2 with channels 2
through 6 in each.
spw=’0:0~10;15~60’; spectral window 0 with
channels 0-10,15-60. (NOTE ‘;’ to separate
channel selections)
spw=’0:0~10^2,1:20~30^5’; spw 0, channels
0,2,4,6,8,10, spw 1, channels 20,25,30 
type ‘help par.selection’ for more examples.

intent (string='') - Select observing intent

default: ‘’ (no selection by intent)

Example: intent=’BANDPASS’ (selects data

labelled with BANDPASS intent)

addmodel (bool=False) - add MODEL_DATA along with CORRECTED_DATA?

Default: False (model will not be added)
Options: False|True
If False, it will add/reset only CORRECTED_DATA,
model visibilities will then be evaluated when
needed.