Examples
Detailed description of keyword arguments:
--- Input/Output parameters ---
vis -- Name of input visibility file
default: ''; example: vis='ngc5921.ms'
outputvis -- Name of output visibility file or Multi-MS
default: ''; example: outputvis='ngc5921.mms'
keepmms -- Create a Multi-MS as the output if the input is a Multi-MS.
default: True
By default it will create a Multi-MS when the input is a Multi-MS.
The output Multi-MS will have the same partition axis of the input MMS.
See 'help partition' for more information on the MMS format.
NOTE: It is not possible to combine the spws if the input MMS was partitioned with
separationaxis='spw'. In this case, the task will abort with an error.
--- Data selection parameters ---
field -- Select field using field id(s) or field name(s).
[run listobs to obtain the list iof d's or names]
default: ''=all fields If field string is a non-negative
integer, it is assumed to be a field index
otherwise, it is assumed to be a field name
field='0~2'; field ids 0,1,2
field='0,4,5~7'; field ids 0,4,5,6,7
field='3C286,3C295'; fields named 3C286 and 3C295
field = '3,4C*'; field id 3, all names starting with 4C
spw -- Select spectral window/channels
default: ''=all spectral windows and channels
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
spw='0,10,3:3~45'; spw 0,10 all channels, spw 3 - chans 3 to 45.
spw='0~2:2~6'; spw 0,1,2 with channels 2 through 6 in each.
spw = '*:3~64' channels 3 through 64 for all sp id's
spw = ' :3~64' will NOT work.
NOTE: mstransform does not support multiple channel ranges per
spectral window (';').
scan -- Scan number range
default: ''=all
antenna -- Select data based on antenna/baseline
default: '' (all)
Non-negative integers are assumed to be antenna indices, and
anything else is taken as an antenna name.
examples:
antenna='5&6': baseline between antenna index 5 and index 6.
antenna='VA05&VA06': baseline between VLA antenna 5 and 6.
antenna='5&6;7&8': baselines 5-6 and 7-8
antenna='5': all baselines with antenna 5
antenna='5,6,10': all baselines including antennas 5, 6, or 10
antenna='5,6,10&': all baselines with *only* antennas 5, 6, or
10. (cross-correlations only. Use &&
to include autocorrelations, and &&&
to get only autocorrelations.)
antenna='!ea03,ea12,ea17': all baselines except those that
include EVLA antennas ea03, ea12, or
ea17.
correlation -- Correlation types or expression.
default: '' (all correlations)
example: correlation='XX,YY'
timerange -- Select data based on time range:
default: '' (all); examples,
timerange = 'YYYY/MM/DD/hh:mm:ss~YYYY/MM/DD/hh:mm:ss'
Note: if YYYY/MM/DD is missing date, timerange defaults to the
first day in the dataset
timerange='09:14:0~09:54:0' picks 40 min on first day
timerange='25:00:00~27:30:00' picks 1 hr to 3 hr 30min
on next day
timerange='09:44:00' data within one integration of time
timerange='>10:24:00' data after this time
array -- (Sub)array number range
default: ''=all
uvrange -- Select data within uvrange (default units meters)
default: ''=all; example:
uvrange='0~1000klambda'; uvrange from 0-1000 kilo-lambda
uvrange='>4klambda';uvranges greater than 4 kilo-lambda
uvrange='0~1000km'; uvrange in kilometers
observation -- Select by observation ID(s)
default: ''=all
feed -- Selection based on the feed - NOT IMPLEMENTED YET
default: ''=all
datacolumn -- Which data column to use for processing (case-insensitive).
default: 'all';
options: 'data', 'model', 'corrected', 'all','float_data', 'lag_data',
'float_data,data', 'lag_data,data'.
example: datacolumn='data'
NOTE: 'all' = whichever of the above that are present. If the requested
column does not exist, the task will exit with an error.
mode -- Frequency Specification:
NOTE: See examples below:
default: 'channel'
mode = 'channel'; Use with nchan, start, width to specify
output spw. Produces equidistant grid based on first
selected channel. See examples below.
mode = 'velocity', means channels are specified in
velocity.
mode = 'frequency', means channels are specified in
frequency.
mode = 'channel_b', alternative 'channel' mode.
Does not force an equidistant grid. Faster.
>>> mode expandable parameters
Start, width are given in units of channels, frequency
or velocity as indicated by mode
nchan -- Number of channels in output spw
default: -1 = all channels; example: nchan=3
start -- Start or end input channel (zero-based) depending on the sign of the width parameter
default=0; example: start=5
width -- Output channel width in units of the input
channel width (sign indicates whether the start parameter is lower(+) or upper(-) end of the range)
default=1; example: width=4
interpolation -- Interpolation method (linear, nearest, cubic, spline, fftshift)
default = 'linear'
examples:
spw = '0,1'; mode = 'channel'
will produce a single spw containing all channels in spw
0 and 1
spw='0:5~28^2'; mode = 'channel'
will produce a single spw made with channels
(5,7,9,...,25,27)
spw = '0'; mode = 'channel': nchan=3; start=5; width=4
will produce an spw with 3 output channels
new channel 1 contains data from channels (5+6+7+8)
new channel 2 contains data from channels (9+10+11+12)
new channel 3 contains data from channels (13+14+15+16)
spw = '0:0~63^3'; mode='channel'; nchan=21; start = 0;
width = 1
will produce an spw with 21 channels
new channel 1 contains data from channel 0
new channel 2 contains data from channel 2
new channel 21 contains data from channel 61
spw = '0:0~40^2'; mode = 'channel'; nchan = 3; start =
5; width = 4
will produce an spw with three output channels
new channel 1 contains channels (5,7)
new channel 2 contains channels (13,15)
new channel 3 contains channels (21,23)
phasecenter -- Direction measure or fieldid. To be used in mosaics to indicate
the center direction to be used in the spectral coordinate transformation.
default: '' (first selected field)
options: FIELD_ID (int) or center coordinate measure (str).
example: phasecenter=6 or phasecenter='J2000 19h30m00 -40d00m00'
restfreq -- Specify rest frequency to use for output image
default='' Occasionally it is necessary to set this (for
example some VLA spectral line data). For example for
NH_3 (1,1) put restfreq='23.694496GHz'
outframe -- output reference frame (not case-sensitive)
possible values: LSRK, LSRD, BARY, GALACTO, LGROUP, CMB, GEO, TOPO, or SOURCE
(SOURCE is meant for solar system work and corresponds to GEO + radial velocity
correction for ephemeris objects).
default='' (keep original reference frame) ; example: outframe='BARY'
veltype -- definition of velocity (in mode)
default = 'radio'
hanning -- if true, Hanning smooth frequency channel data to remove Gibbs ringing