<casaxml xsi:schemaLocation="http://casa.nrao.edu/schema/casa.xsd file:///opt/casa/code/xmlcasa/xml/casa.xsd" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://casa.nrao.edu/schema/psetTypes.html">
<task category="manipulation" name="concat" type="function">
<shortdescription>Concatenate several visibility data sets.</shortdescription>
<description>
The list of data sets given in the vis argument are chronologically
concatenated into an output data set in concatvis, i.e. the data sets
in vis are first ordered by the time of their earliest integration and
then concatenated. If concatvis already exists (e.g., it is the same
as the first input data set), then the other input data sets will be
appended to the concatvis data set.There is no limit to the number of
input data sets.
If there are fields whose direction agrees within the direction will
be the one from the chronologically first input MS. Spectral windows
for each data set with the same chanelization, and within a specified
frequency tolerance of another data set will be combined into one
spectral window.
If none of the input data sets have any scratch columns (model and
corrected columns), none are created in the concatvis. Otherwise
these columns are created on output and initialized to their default
value (1 in model column, data in corrected column) for those data
with no input columns.
Each appended dataset is assigned a new observation id (provided the
entries in the observation table are indeed different).
</description>
<input>
<param mustexist="true" name="vis" type="pathVec">
<shortdescription>Name of input visibility file</shortdescription>
<description>Name of input visibility file
default: none
Example:
vis='['src2.ms','ngc5921.ms','ngc315.ms']
</description>
<value/>
</param>
<param name="concatvis" type="string">
<shortdescription>Name of output visibility file</shortdescription>
<description>Name of visibility file that will contain the
concatenated data
default: none
Example: concatvis='outvis.ms'
Note: if this file exits on disk then the input
files are added to this file. Otherwise the new
file contains the concatenated data. Be careful
here when concatenating to an existing file.
</description>
<value/>
</param>
<param name="freqtol" type="any">
<shortdescription>Frequency shift tolerance for considering data as the same spwid</shortdescription>
<description>Frequency shift tolerance for considering data as the
same spwid. The number of channels must also be the same.
Default: '' == 1 Hz
Example: freqtol='10MHz' will not combine spwid
unless they are within 10 MHz.
Note: This option is useful to combine spectral
windows with very slight frequency differences
caused by Doppler tracking, for example.
</description>
<any type="variant"/>
<value type="string"/>
</param>
<param name="dirtol" type="any">
<shortdescription>Direction shift tolerance for considering data as the same field</shortdescription>
<description>Direction shift tolerance for considering data as the
same field
Default: '' == 1 mas (milliarcsec)
Example: dirtol='1arcsec' will not combine
data for a field unless their phase center
differ by less than 1 arcsec.
Note: If the field names are different in the
input data sets, the name in the output data set
will be the first relevant data set in the list.
</description>
<any type="variant"/>
<value type="string"/>