casacore::TableMeasValueDesc Class Reference

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

#include <TableMeasValueDesc.h>

List of all members.

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

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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

1.  // 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 107 of file TableMeasValueDesc.h.

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Constructor & Destructor Documentation

casacore::TableMeasValueDesc::TableMeasValueDesc

(

)

Null constructor.

casacore::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.

casacore::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 121 of file TableMeasValueDesc.h.

casacore::TableMeasValueDesc::TableMeasValueDesc

(

const Char *

columnName

)

[inline]

Definition at line 123 of file TableMeasValueDesc.h.

casacore::TableMeasValueDesc::TableMeasValueDesc

(

const TableMeasValueDesc &

that

)

Copy constructor.

casacore::TableMeasValueDesc::~TableMeasValueDesc

(

)

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Member Function Documentation

void casacore::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& casacore::TableMeasValueDesc::columnName

(

)

const [inline]

Get the name of the underlying column.

Definition at line 143 of file TableMeasValueDesc.h.

References itsColumn.

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

TableMeasValueDesc& casacore::TableMeasValueDesc::operator=

(

const TableMeasValueDesc &

that

)

Assignment operator.

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

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

Write the actual keywords.

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Member Data Documentation

String casacore::TableMeasValueDesc::itsColumn [private]

Definition at line 147 of file TableMeasValueDesc.h.

Referenced by columnName().

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

• casacore/measures/TableMeasures/TableMeasValueDesc.h