casacore::DerivedMSCal Class Reference

Virtual column engine to return derived MS values. More...

#include <DerivedMSCal.h>

Inheritance diagram for casacore::DerivedMSCal:

Public Member Functions
	DerivedMSCal ()
	Create the data manager.
	DerivedMSCal (const Record &spec)
	Create a Lofar storage manager with the given name.
	~DerivedMSCal ()
virtual DataManager *	clone () const
	Clone this object.
virtual void	prepare ()
	Prepare the object.
virtual String	dataManagerType () const
	Get the type name of the data manager (i.e.
virtual Record	dataManagerSpec () const
	Record a record containing data manager specifications.
virtual Bool	canAddColumn () const
	Columns can be added.
virtual Bool	canRemoveColumn () const
	Columns can be removed.
Static Public Member Functions
static DataManager *	makeObject (const String &dataManName, const Record &spec)
	Make the object from the type name string.
static void	registerClass ()
	Register the class name and the static makeObject "constructor".
Private Member Functions
	DerivedMSCal (const DerivedMSCal &that)
	Copy constructor cannot be used.
DerivedMSCal &	operator= (const DerivedMSCal &that)
	Assignment cannot be used.
virtual void	addColumn (DataManagerColumn *)
	Do the final addition of a column.
virtual void	removeColumn (DataManagerColumn *)
	Remove a column from the data file.
virtual DataManagerColumn *	makeScalarColumn (const String &aName, int aDataType, const String &aDataTypeID)
	Create a column in the storage manager on behalf of a table column.
virtual DataManagerColumn *	makeIndArrColumn (const String &aName, int aDataType, const String &aDataTypeID)
	Create an indirect array column.
Private Attributes
MSCalEngine	itsEngine
vector< DataManagerColumn * >	itsColumns

Detailed Description

Virtual column engine to return derived MS values.

Intended use:

Public interface

Review Status

Test programs:: tDerivedMSCal

Prerequisite

The Table Data Managers concept as described in module file Tables.h
MeasurementSet

Synopsis

DerivedMSCal makes it possible to have virtual columns for the derived MeasurementSet values hourangle, parallactic angle, azimuth/elevation, and local sidereal time. In this way such derived values appear to be ordinary columns with the exception that no values can be put into them.

The following columns can be defined:

HA is the hourangle of the array center (observatory position).
HA1 is the hourangle of ANTENNA1.
HA2 is the hourangle of ANTENNA2.
HADEC is the hourangle/DEC of the array center (observatory position).
HADEC1 is the hourangle/DEC of ANTENNA1.
HADEC2 is the hourangle/DEC of ANTENNA2.
LAST is the local sidereal time of the array center.
LAST1 is the local sidereal time of ANTENNA1.
LAST2 is the local sidereal time of ANTENNA2.
PA1 is the parallactic angle of ANTENNA1.
PA2 is the parallactic angle of ANTENNA2.
AZEL1 is the azimuth/elevation of ANTENNA1.
AZEL2 is the azimuth/elevation of ANTENNA2.
UVW_J2000 is the UVW coordinates in J2000 (in meters)

All columns have data type double and unit radian (except UVW). The HADEC, AZEL, and UVW columns are array columnns while the others are scalar columns.

This engine is meant for a MeasurementSet, but can be used for any table containing an ANTENNA and FIELD subtable and the relevant columns in the main table (ANTENNA1 and/or ANTENNA2, FIELD_ID, and TIME).
In principle the array center is the Observatory position, which is taken from the Measures Observatory table using the telescope name found in the OBSERVATION subtable. However, if the subtable is not defined or empty or if the telescope name is unknown, the position of the first antenna is used as the array position.

The engine can also be used for a CASA Calibration Table. It understands how it references the MeasurementSets. Because calibration tables contain no ANTENNA2 columns, columns XX2 are the same as XX1.

Motivation

It makes it possible to use generic table software (like querying, plotting, tablebrowser) on these values.

Example

The following example shows how to add such columns to an MS and use them thereafter.

 // Open the table for update (to be able to add the columns).
 Table tab ("tDerivedMSCal_tmp.tab", Table::Update);
 // Define the columns and add them using DerivedMSCal.
 TableDesc td;
 td.addColumn (ScalarColumnDesc<double>("HA1"));
 td.addColumn (ScalarColumnDesc<double>("HA2"));
 td.addColumn (ScalarColumnDesc<double>("PA1"));
 td.addColumn (ScalarColumnDesc<double>("PA2"));
 DerivedMSCal dataMan;
 tab.addColumn (td, dataMan);
 // Print values of all rows.
 ScalarColumn<double> ha1(tab, "HA1");
 ScalarColumn<double> ha2(tab, "HA2");
 ScalarColumn<double> pa1(tab, "PA1");
 ScalarColumn<double> pa2(tab, "PA2");
 for (uInt row=0; row<tab.nrow(); ++row) {
 cout << ha1(row)<<' '<<ha2(row)<<' '<<pa1(row)<<' '<<pa2(row)<<endl;
 }

To Do

Take care of the feeds and their offsets.
Have a conversion engine per field/antenna/feed?

Definition at line 130 of file DerivedMSCal.h.

Constructor & Destructor Documentation

casacore::DerivedMSCal::DerivedMSCal ( )

Create the data manager.

casacore::DerivedMSCal::DerivedMSCal ( const Record & spec ) [explicit]

Create a Lofar storage manager with the given name.

The specifications are part of the record (as created by dataManagerSpec).

casacore::DerivedMSCal::~DerivedMSCal ( )

casacore::DerivedMSCal::DerivedMSCal ( const DerivedMSCal & that ) [private]

Copy constructor cannot be used.

Member Function Documentation

virtual void casacore::DerivedMSCal::addColumn ( DataManagerColumn * ) [private, virtual]

Do the final addition of a column.

It won't do anything.

Reimplemented from casacore::DataManager.

virtual Bool casacore::DerivedMSCal::canAddColumn ( ) const [virtual]

Columns can be added.

Reimplemented from casacore::DataManager.

virtual Bool casacore::DerivedMSCal::canRemoveColumn ( ) const [virtual]

Columns can be removed.

Reimplemented from casacore::DataManager.

virtual DataManager* casacore::DerivedMSCal::clone ( ) const [virtual]

Clone this object.

Implements casacore::DataManager.

virtual Record casacore::DerivedMSCal::dataManagerSpec ( ) const [virtual]

Record a record containing data manager specifications.

Reimplemented from casacore::DataManager.

virtual String casacore::DerivedMSCal::dataManagerType ( ) const [virtual]

Get the type name of the data manager (i.e.

DerivedMSCal).

Implements casacore::DataManager.

virtual DataManagerColumn* casacore::DerivedMSCal::makeIndArrColumn	(	const String &	aName,
		int	aDataType,
		const String &	aDataTypeID
	)			`[private, virtual]`

Create an indirect array column.

Reimplemented from casacore::VirtualColumnEngine.

static DataManager* casacore::DerivedMSCal::makeObject	(	const String &	dataManName,
		const Record &	spec
	)			`[static]`

Make the object from the type name string.

This function gets registered in the DataManager "constructor" map. The caller has to delete the object. The dataManName is not used.

virtual DataManagerColumn* casacore::DerivedMSCal::makeScalarColumn	(	const String &	aName,
		int	aDataType,
		const String &	aDataTypeID
	)			`[private, virtual]`