vlafillerfromdisk

Convert VLA archive data from a disk file to a measurement set

Synopsis
vlafillerfromdisk(msname, filename, project, start, stop, bandname, source, overwrite, verbose, async, freqTolerance)

Description

This global function prevents users from having to explicitly use the vlafiller tool by packaging its functions so they perform a common task ie., copying data from a disk file containing VLA archive data into a measurement set.

In the best case, there are only two arguments which the user must supply in order to successfully use this function, these are the filename and msname arguments. These arguments specify the names of the input vla archive file and the output measurement set. All other arguments are optional. See the diskinput & output functions for more details. Due to the variety of the dataset quality, however, some dataset requires a larger tolerance for frequeny in order to recognize the same spectral window. So the user may need to pass in a proper tolerance according to the specific dataset. As a rule of thumb, executing the filling script first with the default tolerance and examing the generated SPECTRAL_WINDOW subtable of MS will give you a good hint about what is the right tolerance for the frequency to use. For instance, for dataset G192, the proper tolerance for frequency is about 6 times of its channel width( see the glish test script g192_testTolerance.g ), while for dataset NGC7538, a much larger tolerance, 60 times of its channel width, ( see the glish test scripts ngc7538_testTolerance.g ) is required in order to recognize the two related frequencies as the same spectral window. The freqTolerance should be in the unit of Hz.

A number of arguments control what data is copied to the output measurement set. These are:

project: See the selectproject function.
start & stop: See the selecttime function.
bandname: See the selectband function.
source: See the selectsource function^1.7.

The remaining arguments control details of the filling process. The overwrite argument specifies whether the output measurement set is deleted prior to copying the data. See the output function for more details.

The verbose argument controls how much status information is sent to the logger and the async argument controls whether the function should run in the background. See the fill function for more details.

This function returns T is everything went well and F otherwise.

Arguments

msname	The measurement set name.
	Allowed:	string
	Default:	no default
filename	The input file name.
	Allowed:	string
	Default:	no default
project	The observing project name.
	Allowed:	string
	Default:	unset
start	The beginning of the time range.
	Allowed:	string
	Default:	unset
stop	The end of the time range.
	Allowed:	string
	Default:	unset
bandname	The frequency band to select.
	Allowed:	string
	Default:	unset
source	The source name.
	Allowed:	string
	Default:	unset
overwrite	Overwrite an existing file.
	Allowed:	Boolean
	Default:	F
verbose	Send messages when copying each record.
	Allowed:	Boolean
	Default:	F
async	Run this function asynchronously.
	Allowed:	Boolean
	Default:	F
freqTolerance	The tolerance for frequency.
	Allowed:	Double
	Default:	The channel width of the current spectral window in Hz

Returns
T or F

Example

      include 'vlafiller.g'
      vlafillerfromdisk('ab123.ms', 'file1.vla', project='ab123');

This example creates the measurement set called 'ab123.ms' from all the records in the file called 'file1.vla' that come from the observing project called 'AB123'.

Example

      include 'vlafiller.g'
      vlafillerfromdisk(filename='data/G192/AS758\_C030425.xp1',
                        msname='g192\_a.ms', overwrite=T,bandname='K',
                        async=F, freqTolerance=150000.0);

This example shows how a user can pass in a tolerance for the frequency matching. It creates the measurement set called 'g192_a.ms' from all the records in the file called 'data/G192/AS758_C030425.xp1'.

Next: vlafilleroldweights - Function Up: vla - Module Previous: vlafillerfromtape - Function Contents Index

	Package	nrao
	Module	vla

vlafillerfromdisk - Function