<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="split" type="function">
<shortdescription>Create a visibility subset from an existing visibility set</shortdescription>
Split is the general purpose program to make a new data set that is a
subset or averaged form of an existing data set. General selection
parameters are included, and one or all of the various data columns
(DATA, LAG_DATA and/or FLOAT_DATA, MODEL_DATA and/or CORRECTED_DATA)
Split is often used after the initial calibration of the data to make
a smaller Measurement Set with only the data that will be used in
further flagging, imaging and/or self-calibration. Split can average
over frequency (channels) and time (integrations).
The split task uses the MSTransform framework underneath. Split also
supports the Multi-MS (MMS) format as input.
<param mustexist="true" name="vis" type="path">
<shortdescription>Name of input visibility file</shortdescription>
<description>Name of input visibility file
Example: vis='ngc5921.ms'
<param mustexist="false" name="outputvis" type="path">
<shortdescription>Name of output visibility file</shortdescription>
<description>Name of output visibility file
Default: '' (same as vis)
Example: outputvis='ngc5921_out.ms'
IMPORTANT: if a .flagversions file with the name
of the output MS exist, this task will exit with
an error. The user needs to rename or remove the
existing flagbackup or choose a different output
<param name="keepmms" type="bool">
<shortdescription>If the input is a Multi-MS the output will also be a Multi-MS.</shortdescription>
<description>Create a Multi-MS as the output if the input is a
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 CASA Docs for more information on
NOTE: It is not possible to do time average with
combine='scan' if the input MMS was partitioned