MSDataDescColumns.h

This class provides read-only access to the columns in the MSDataDesc Table. It does the declaration of all the Scalar and ArrayColumns with the correct types, so the application programmer doesn't have to worry about getting those right. There is an access function for every predefined column. Access to non-predefined columns will still have to be done with explicit declarations. See ROMSColumns for an example.

The Table that is used to construct this class must not be destroyed (or go out of scope) before this class does. Otherwise the scalar and array columns use by this class will be left dangling.

Motivation

See MSColumns for the motivation.

Member Description

ROMSDataDescColumns(const MSDataDescription& msDataDesc)

Create a columns object that accesses the data in the specified Table

~ROMSDataDescColumns()

The destructor does nothing special

const ROScalarColumn<Bool>& flagRow() const
const ROScalarColumn<Int>& polarizationId() const
const ROScalarColumn<Int>& spectralWindowId() const

Access to required columns

const ROScalarColumn<Int>& lagId() const

Access to optional columns

uInt nrow() const

Convenience function that returns the number of rows in any of the columns

Int match(uInt spwId, uInt polId, Int tryRow=-1)

returns the last row that contains the specified entries in the SPECTRAL_WINDOW_ID & POLARIZATION_ID columns. Returns -1 if no match could be found. Flagged rows can never match. If tryRow is non-negative, then that row is tested to see if it matches before any others are tested. Setting tryRow to a positive value greater than the table length will throw an exception (AipsError).

ROMSDataDescColumns()

void attach(const MSDataDescription& msDataDesc)

ROMSDataDescColumns(const ROMSDataDescColumns&)

ROMSDataDescColumns& operator=(const ROMSDataDescColumns&)

void attachOptionalCols(const MSDataDescription& msDataDesc)

class MSDataDescColumns: public ROMSDataDescColumns

Interface

Public Members

MSDataDescColumns(MSDataDescription& msDataDesc)

~MSDataDescColumns()

ScalarColumn<Bool>& flagRow()

ScalarColumn<Int>& polarizationId()

ScalarColumn<Int>& spectralWindowId()

ScalarColumn<Int>& lagId()

const ROScalarColumn<Bool>& flagRow() const

const ROScalarColumn<Int>& polarizationId() const

const ROScalarColumn<Int>& spectralWindowId() const

const ROScalarColumn<Int>& lagId() const

Protected Members

MSDataDescColumns()

void attach(MSDataDescription& msDataDesc)

Private Members

MSDataDescColumns(const MSDataDescColumns&)

MSDataDescColumns& operator=(const MSDataDescColumns&)

void attachOptionalCols(MSDataDescription& msDataDesc)

Description

Review Status

Reviewed By:: Bob Garwood
Date Reviewed:: 1997/02/01

Prerequisite

MSDataDesc
ScalarColumn

Etymology

MSDataDescColumns stands for MeasurementSet DataDescription Table columns.