casa6

<casaxml xsi:schemaLocation="http://casa.nrao.edu/schema/casa.xsd file:///opt/casa/code/xmlcasa/xml/casa.xsd" xmlns="http://casa.nrao.edu/schema/psetTypes.html" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">

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<task type="function" name="virtualconcat" category="manipulation">

<shortdescription>Concatenate several visibility data sets into a multi-MS</shortdescription>

​

<input>

  <param type="pathVec" name="vis" mustexist="true"><shortdescription>List of names of input visibility files to be concatenated</shortdescription><description>List of names of input visibility files to be concatenated</description>

    <value/>

  </param>

​

  <param type="string" name="concatvis"><shortdescription>Name of the output visibility file (a multi-MS)</shortdescription><description>Name of the output visibility file (a multi-MS)</description>

    <value/>

  </param>

  <param type="any" name="freqtol"><shortdescription>Frequency shift tolerance for considering data as the same spwid</shortdescription><description>Frequency shift tolerance for considering data as the same spwid</description>

    <any type="variant"/>

    <value type="string"/>

  </param>

​

  <param type="any" name="dirtol"><shortdescription>Direction shift tolerance for considering data as the same field</shortdescription><description>Direction shift tolerance for considering data as the same field</description>

    <any type="variant"/>

    <value type="string"/>

  </param>

​

  <param type="bool" name="respectname"><shortdescription>If true, fields with a different name are not merged even if their direction agrees</shortdescription><description>If true, fields with a different name are not merged even if their direction agrees</description>

    <value>True</value>

  </param>

​

  <param type="doubleVec" name="visweightscale"><shortdescription>List of the weight scaling factors to be applied to the individual MSs</shortdescription><description>List of the weight scaling factors to be applied to the individual MSs</description>

    <value/>

  </param>

​

  <param type="bool" name="keepcopy"><shortdescription>If true, a copy of the input MSs is kept in their original place.</shortdescription><description>If true, a copy of the input MSs is kept in their original place.</description>

    <value>False</value>

  </param>

​

  <param type="bool" name="copypointing"><shortdescription>If true, keep the POINTING table information in the output MMS. If false, don\'t.</shortdescription><description>If true, keep the POINTING table information in the output MMS. If false, don\'t.</description>

    <value>True</value>

  </param>

​

</input>

<example>

​

The list of data sets given in the vis argument are moved into an output

multi-MS data set concatvis and virtually concatenated. 

​

NOTE: This task will modify the input datasets by moving them and reindexing them.

If you want to keep a copy of your original data, please set the parameter 

keepcopy to True.

​

There is no limit to the number of input data sets.

​

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.

​

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.

​

A field position in one data set that is within a specified direction tolerance

of another field position in any other data set will be combined into one

field.  The field names need not be the same---only their position is used.

​

Each appended dataset is assigned a new observation id if the corresponding

rows in the observation table are not the same.

​

Keyword arguments:

vis -- Name of input visibility files to be combined

        default: none; example: vis = ['src2.ms','ngc5921.ms','ngc315.ms']

concatvis -- Name of visibility file that will contain the concatenated data

        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.

        default: none; example: concatvis='src2.ms'

                 example: concatvis='outvis.ms'

​

        other examples: 

           virtualconcat(vis=['src2.ms','ngc5921.ms'], concatvis='out.mms') 

               will concatenate 'ngc5921.ms' and 'src2.ms' into a file named 

               'out.mms'; the original 'ngc5921.ms' and 'src2.ms' are gone.

               'out.mms' is a multims. As most of the data is only moved, not 

               copied, this is faster and subsequent tasks can run in parallel

               on the subMSs of out.mms.

           virtualconcat(vis=['src2.ms','ngc5921.ms'], concatvis='out.mms', keepcopy=True) 

               will concatenate 'ngc5921.ms' and 'src2.ms' into a file named 

               'out.mms'; the original 'ngc5921.ms' and 'src2.ms' are as before

               but you consume more disk space and time for the copy.

               .

​

     Note: run flagmanager to save flags in the concatvis

​

freqtol -- Frequency shift tolerance for considering data to be in the same

           spwid.  The number of channels must also be the same.

        default: ''  do not combine unless frequencies are equal

        example: freqtol='10MHz' will not combine spwid unless they are

           within 10 MHz.

        Note: This option is useful to conbine spectral windows with very slight

           frequency differences caused by Doppler tracking, for example.

​

dirtol -- Direction shift tolerance for considering data as the same field

        default: '' means always combine.

        example: dirtol='1.arcsec' will not combine data for a field unless

           their phase center differ by less than 1 arcsec.  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.

​

respectname -- If true, fields with a different name are not merged even if their 

        direction agrees (within dirtol). 

        default: True

​

visweightscale -- The weights of the individual MSs will be scaled in the concatenated

        output MS by the factors in this list. Useful for handling heterogeneous arrays.

        Use plotms to inspect the "Wt" column as a reference for determining the scaling 

        factors. See the cookbook for more details.

        example: [1.,3.,3.] - scale the weights of the second and third MS by a factor 3.

        default: [] (empty list) - no scaling

​

keepcopy -- If true, a copy of the input MSs is kept in their original place.

        default: false

​

copypointing -- If true, the POINTING table information will be present in the output.

                If false, the result is an empty POINTING table.

         default: true

​

</example> 

​

<returns>void</returns></task>

</casaxml>