Synopsis

This class is a container that allows many SkyComponents to be grouped together and manipulated as one large compound component. The major operations of this class are:

Functions to traverse the list and extract individual components

See the nelements & component functions

Functions to add and delete components.

See the add, remove & copy functions

Functions to designate components as being selected or not.

See the select, deselect & selected functions

Functions to sample the flux of the components in any direction and frequency or to grid them onto an Image.

See the sample & project functions.

Functions to save the components to a table and read them back again

See the rename function and the appropriate constructor.

Functions to manipulate the flux of all components

See the setFlux, convertFluxUnit & convertFluxPol functions.

Functions to manipulate the reference direction of all components

See the setRefDirection & convertRefFrame functions.

functions to sort the components

See the sort, type & namel functions.

ComponentLists are memory based objects that can write their contents to and from disk (ie a Table). To read a componentList from a Table the appropriate constructor must be used. Alternatively an empty componentlist can be created that is not associated with a Table. To save the list to disk it must be given a name. This is done using the rename function. This will rename the Table if the ComponentList was already associated with a Table. Saving changes to the table on disk happens automatically when the list is destructed or reset via the assignment operator (unless the table was opened read-only).

The elements of a componentlist (ie., SkyComponents) are accessed via the component functions. These functions return the SkyComponent by reference and hence manipulating the supplied component manipulates the specified element of the list.

Example

Example 1:

Motivation

Thrown Exceptions

• AipsError - If an internal inconsistancy is detected, when compiled in debug mode only.

To Do

• Nothing I hope. But I expect users will disagree.

Member Description

enum SortCriteria

ComponentList()

ComponentList(const Path& fileName, const Bool readOnly=False)

Read a componentList from an existing table. By default the Table is opened read-write. Any subsequent changes made to a list opened read-only (i.e. via add(), remove(), or editing a non-const member component returned by component()) will not be saved to disk.

ComponentList(const ComponentList& other)

The Copy constructor uses reference semantics

~ComponentList()

The destructor saves the list to disk if it has a name (assigned using the setName member function)

ComponentList& operator=(const ComponentList& other)

The assignment operator uses reference semantics

Bool isPhysical(const Vector<Int>& index) const

Returns True if all the specified components are physically plausable. See the isPhysical function in the SkyCompBase class for a precise definition of what this means.

Thrown Exceptions

• AipsError - If the index is equal to or larger than the number of elements in the list or less than zero

Flux<Double> sample(const MDirection& sampleDir, const MVAngle& pixelLatSize, const MVAngle& pixelLongSize, const MFrequency& centerFreq) const

Calculate the integrated flux of all the members of the componentlist at the specified direction & frequency, in a pixel of specified size.

void sample(Cube<Double>& samples, const Unit& reqUnit, const Vector<MVDirection>& directions, const MeasRef<MDirection>& dirRef, const MVAngle& pixelLatSize, const MVAngle& pixelLongSize, const Vector<MVFrequency>& frequencies, const MeasRef<MFrequency>& freqRef) const

Same as the previous function except that many directions & frequencies are done at once. The Flux is added into the values supplied in the samples argument and this cube must have dimensions of: [4, nDirs, nFreqs]. The polarisation and units of the flux added are specified with the reqUnit and reqPol arguments.

void add(SkyComponent component)

Add a SkyComponent to the end of the ComponentList. The list length is increased by one when using this function. By default the newly added component is not selected. Note that it is possible to add a component to a list that was opened read-only; however, the table on disk will not be updated with new component.

void remove(const uInt& index)
void remove(const Vector<Int>& indices)

Remove the specified SkyComponent(s) from the ComponentList. After removing a component all the components with an indices greater than this one will be reduced by one. For example in a five element list removing elements [0,2,4] will result in a two element list, now indexed as elements zero and one, containing what was previously the second and fourth components. Note that it is possible to remove a component from a list that was opened read-only; however, the table on disk will not be updated accordingly.

Thrown Exceptions

• AipsError - If the index is equal to or larger than the number of elements in the list or is negative.

uInt nelements() const

returns how many components are in the list.

void deselect(const Vector<Int>& index)

deselect the specified component. Throws an exception (AipsError) if any element in the index is out of range, ie. index >= nelements().

Thrown Exceptions

• AipsError - If the index is equal to or larger than the number of elements in the list or less than zero

void select(const Vector<Int>& index)

select the specified component. Throws an exception (AipsError) if any element in the index is out of range, ie. index >= nelements().

Thrown Exceptions

• AipsError - If the index is equal to or larger than the number of elements in the list or less than zero

Vector<Int> selected() const

Returns a Vector whose indices indicate which components are selected

void setLabel(const Vector<Int>& which, const String& newLabel)

set the label on the specified components to the specified string

Thrown Exceptions

• AipsError - If the index is equal to or larger than the number of elements in the list or less than zero

void setFlux(const Vector<Int>& which, const Flux<Double>& newFlux)

set the flux on the specified components to the specified flux

Thrown Exceptions

• AipsError - If the index is equal to or larger than the number of elements in the list or less than zero

void convertFluxUnit(const Vector<Int>& which, const Unit& unit)

convert the flux on the specified components to the specified units

Thrown Exceptions

• AipsError - If the index is equal to or larger than the number of elements in the list or less than zero

void convertFluxPol(const Vector<Int>& which, ComponentType::Polarisation pol)

convert the flux on the specified components to the specified polarisation representation

Thrown Exceptions

• AipsError - If the index is equal to or larger than the number of elements in the list or less than zero

void setRefDirection(const Vector<Int>& which, const MVDirection& newDir)

set the reference direction on the specified components to the specified direction. The reference frame is not changed, use the setRefFrame function to do that.

Thrown Exceptions

• AipsError - If the index is equal to or larger than the number of elements in the list or less than zero

void setRefDirectionFrame(const Vector<Int>& which, MDirection::Types newFrame)

set the reference direction frame on the specified components to the specified one. Does not convert the direction values.

Thrown Exceptions

• AipsError - If the index is equal to or larger than the number of elements in the list or less than zero

void convertRefDirection(const Vector<Int>& which, MDirection::Types newFrame)

Convert the reference direction frame on the specified components to the specified one. Changes the direction values.

Thrown Exceptions

• AipsError - If the index is equal to or larger than the number of elements in the list or less than zero

void setShape(const Vector<Int>& which, const ComponentShape& newShape)

set the shape on the specified components to the specified one.

Thrown Exceptions

• AipsError - If the index is equal to or larger than the number of elements in the list or less than zero

void setShapeParms(const Vector<Int>& which, const ComponentShape& newShape)

set the shape on the specified components to the specified one. However this function unlike the previous one does not change the reference direction to the one specified in the newShape object.

Thrown Exceptions

• AipsError - If the index is equal to or larger than the number of elements in the list or less than zero

void setSpectrum(const Vector<Int>& which, const SpectralModel& newSpectrum)

set the spectrum on the specified components to the specified one.

Thrown Exceptions

• AipsError - If the index is equal to or larger than the number of elements in the list or less than zero

void setSpectrumParms(const Vector<Int>& which, const SpectralModel& newSpectrum)

set the spectrum on the specified components to the specified one. However this function unlike the previous one does not change the reference frequency to the one specified in the newSpectrum object.

Thrown Exceptions

• AipsError - If the index is equal to or larger than the number of elements in the list or less than zero

void setRefFrequency(const Vector<Int>& which, const MVFrequency& newFreq)

set the reference frequency on the specified components to the specified frequency. The reference frame is not changed, use the setRefFrequencyFrame function to do that.

Thrown Exceptions

• AipsError - If the index is equal to or larger than the number of elements in the list or less than zero

void setRefFrequencyFrame(const Vector<Int>& which, MFrequency::Types newFrame)

set the reference frequency frame on the specified components to the specified one. Does not convert the frequency values.

Thrown Exceptions

• AipsError - If the index is equal to or larger than the number of elements in the list or less than zero

void setRefFrequencyUnit(const Vector<Int>& which, const Unit& unit)

set the reference frequency unit on the specified components to the specified one. The unit must have the same dimensions as the Hz.

Thrown Exceptions

• AipsError - If the index is equal to or larger than the number of elements in the list or less than zero

const SkyComponent& component(const uInt& index) const
SkyComponent& component(const uInt& index)

returns a reference to the specified element in the list.

Thrown Exceptions

• AipsError - If the list is associated with a table that was opened readonly (non-const version only).
• AipsError - If the index is equal to or larger than the number of elements in the list.

void rename(const Path& newName, const Table::TableOption option=Table::New)

Make the ComponentList persistant by supplying a filename. If the ComponentList is already associated with a Table then the Table will be renamed. Hence this function cannot be used with ComponentLists that are constructed with readonly=True.

Thrown Exceptions

• AipsError - If the list is associated with a table that was opened readonly
• AipsError - If option is Table::Old as this does not make sense

ComponentList copy() const

Make a real copy of this componentList. As the copy constructor and the assignment operator use reference semantics this is the only way to get a distinct version of the componentList.

void sort(ComponentList::SortCriteria criteria)

Sort the components in the list using the given criteria.

static String name(ComponentList::SortCriteria enumerator)

Convert the SortCriteria enumerator to a string

static ComponentList::SortCriteria type(const String& criteria)

Convert a given String to a Type enumerator

Bool ok() const

Function which checks the internal data of this class for consistant values. Returns True if everything is fine otherwise returns False.

Bool fromRecord(String& error, const RecordInterface& inRec)

methods to store itself as a Record and recover from a Record its state

Bool toRecord(String& error, RecordInterface& outRec)

void createTable(const Path& fileName, const Table::TableOption option)

void writeTable()

Thrown Exceptions

• AipsError - If the table is not writable

void readTable(const Path& fileName, const Bool readOnly)

Private function to read the components from disk

Thrown Exceptions

• AipsError - If the table is not readable
• AipsError - If the table is not writable (and readOnly==False)