Definition of a Measure Value in a Table. More...

#include <TableMeasValueDesc.h>

Public Member Functions
	TableMeasValueDesc ()
	Null constructor.
	TableMeasValueDesc (const TableDesc &, const String &columnName)
	Construct the MeasValue column descriptor for the given column.
	TableMeasValueDesc (const String &columnName)
	Construct the MeasValue column descriptor for the given column.
	TableMeasValueDesc (const Char *columnName)
	TableMeasValueDesc (const TableMeasValueDesc &that)
	Copy constructor.
	~TableMeasValueDesc ()
TableMeasValueDesc &	operator= (const TableMeasValueDesc &that)
	Assignment operator.
void	write (TableDesc &, const TableRecord &measInfo)
	Write the type, unit, and MEASINFO record into the column keywords.
void	write (Table &, const TableRecord &measInfo)
const String &	columnName () const
	Get the name of the underlying column.
Private Member Functions
void	writeKeys (TableRecord &columnKeyset, const TableRecord &measInfo)
	Write the actual keywords.
void	checkColumn (const TableDesc &td) const
	Throw an exception if the quantum column doesn't exist or is of the wrong type.
Private Attributes
String	itsColumn

Detailed Description

Definition of a Measure Value in a Table.

Intended use:

Public interface

Review Status

Reviewed By:: Bob Garwood
Date Reviewed:: 1999/12/23
Test programs:: tTableMeasures

Prerequisite

Measures
Tables
TableMeasDesc

Synopsis

TableMeasValueDesc is a class for setting up the Measure value component of the TableMeasDesc in the TableMeasures system. Its purpose it to specify the Table column to be used as a Measure column through which Measures are subsequently written to and read from via either an ArrayMeasColumn or ScalarMeasColumn object.

The column used as the Measure column is always an ArrayColumn<Double> irrespective of whether it is to store scalars or arrays of Measures and irrespective of the type of Measure.

Example

       // Add a column to the table.  This column is to be used to store
       // MPositions.  Measure columns are alway ArrayColumn<Double>
       ArrayColumnDesc<Double> cdPosCol("MPosColumn", "MPosition column");
       td.addColumn(cdPosCol);
       ..\.
       // create the TableMeasValueDesc object
       TableMeasValueDesc valueDesc(td, "MPosColumn");

For an example of the use of the TableMeasValueDesc class in the context of a full TableMeasDesc declaration see class TableMeasDesc .

Motivation

Creating the required keyword for the definition of a Measure in a Table is somewhat complicated. This class assists in that process.

Thrown Exceptions

AipsError if the specified column doesn't exist or it isn't an ArrayColumn or its type is not Double.

Definition at line 106 of file TableMeasValueDesc.h.

Constructor & Destructor Documentation

casa::TableMeasValueDesc::TableMeasValueDesc ( )

Null constructor.

casa::TableMeasValueDesc::TableMeasValueDesc	(	const TableDesc &	,
		const String &	columnName
	)

Construct the MeasValue column descriptor for the given column.

The column must be a column of type Double and should exist in the TableDesc.

casa::TableMeasValueDesc::TableMeasValueDesc ( const String & columnName ) [inline]

Construct the MeasValue column descriptor for the given column.

Checking if the column exists is done in the write function.

Definition at line 120 of file TableMeasValueDesc.h.

casa::TableMeasValueDesc::TableMeasValueDesc ( const Char * columnName ) [inline]

Definition at line 122 of file TableMeasValueDesc.h.

casa::TableMeasValueDesc::TableMeasValueDesc ( const TableMeasValueDesc & that )

Copy constructor.

casa::TableMeasValueDesc::~TableMeasValueDesc ( )

Member Function Documentation

void casa::TableMeasValueDesc::checkColumn ( const TableDesc & td ) const [private]

Throw an exception if the quantum column doesn't exist or is of the wrong type.

const String& casa::TableMeasValueDesc::columnName ( ) const [inline]

Get the name of the underlying column.

Definition at line 142 of file TableMeasValueDesc.h.

References itsColumn.

Referenced by casa::TableMeasDescBase::columnName().

TableMeasValueDesc& casa::TableMeasValueDesc::operator= ( const TableMeasValueDesc & that )

Assignment operator.

void casa::TableMeasValueDesc::write	(	TableDesc &	,
		const TableRecord &	measInfo
	)

Write the type, unit, and MEASINFO record into the column keywords.

It checks if the column exists in the given table description.

void casa::TableMeasValueDesc::write	(	Table &	,
		const TableRecord &	measInfo
	)

void casa::TableMeasValueDesc::writeKeys	(	TableRecord &	columnKeyset,
		const TableRecord &	measInfo
	)		`[private]`

Write the actual keywords.

Member Data Documentation

String casa::TableMeasValueDesc::itsColumn [private]

Definition at line 146 of file TableMeasValueDesc.h.

Referenced by columnName().

The documentation for this class was generated from the following file:

casacore/measures/TableMeasures/TableMeasValueDesc.h

Public Member Functions

Private Member Functions

Private Attributes