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ms.virtconcatenate - Function

1.3.1 Concatenate two measurement sets virtually


Description

This function virtually concatenates two measurement sets together such that they can later be turned into a multi-MS with createmultims().

You need to open the measurement set for writing in order to use this function.

Arguments

Inputs

msfile

The name of the measurement set to append

allowed:

string

Default:

auxfilename

The name of a auxiliary file which is needed when more than two MSs are to be concatenated.

allowed:

string

Default:

freqtol

Frequency difference within which 2 spectral windows are considered similar; e.g ’10Hz’

allowed:

any

Default:

variant 1Hz

dirtol

Direction difference within which 2 fields are considered the same; e.g ’1mas’

allowed:

any

Default:

variant 1mas

weightscale

Scale the weights of the MS to be appended by this factor

allowed:

float

Default:

1.

respectname

If true, fields with a different name are not merged even if their direction agrees

allowed:

bool

Default:

true

Returns
bool

Example

 
 
 
      ms.open("3C273XC1.ms", nomodify=False)  
      ms.virtconcatenate("3C273XC1-2.ms", ’3Caux.dat’, ’1GHz’, ’1arcsec’)  
      ms.virtconcatenate("3C273XC1-3.ms", ’3Caux.dat’, ’1GHz’, ’1arcsec’)  
      ms.close()  
      os.remove(’3Caux.dat’)  
      m.createmultims(concatvis,  
                      ["3C273XC1.ms","3C273XC1-2.ms","3C273XC1-3.ms"],  
      [],  
      True, # nomodify  
      False,# lock  
      True) # copysubtables from first to all other members  
      ms.close()  
 
    This example virtually appends the data from the 3C273XC1-2 and 3C273XC1-3 to  
    the end of the 3C273XC1 measurement set. Its going to assume a  
    frequency tolerance of 1GHz and position tolerance of 1 arcsec in  
    deciding if the spw and field in the measurementsets are  
    similar or not. The file 3Caux.dat which is created in the process is  
    no longer needed after the last call to virtconcatenate() and can  
    be deleted.  

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