casacore::MVDirection Class Reference

Vector of three direction cosines. More...

#include <MVDirection.h>

Inheritance diagram for casacore::MVDirection:

List of all members.

Public Member Functions
	MVDirection ()
	Default constructor generates a direction to the pole (i.e.
	MVDirection (const MVPosition &other)
	Copy constructor.
	MVDirection (Double in0)
	Constructs with elevation = 0.
	MVDirection (const Quantity &angle0)
	MVDirection (Double in0, Double in1, Double in2)
	Creates a specified vector.
	MVDirection (Double angle0, Double angle1)
	Creates the direction cosines from specified angles along equator (azimuth) and towards pole (,elevation).
	MVDirection (const Quantity &angle0, const Quantity &angle1)
	Creates the direction cosines from specified angles.
	MVDirection (const Quantum< Vector< Double > > &angle)
	If not enough angles: pole (=(0,0,1)) assumed (if none), or elevation =0 (if 1); direction cosines assumed (if 3).
	MVDirection (const Vector< Double > &other)
	Create from Vector.
	MVDirection (const Vector< Quantity > &other)
MVDirection &	operator= (const MVDirection &other)
	Copy assignment.
	~MVDirection ()
	Destructor.
MVDirection &	operator+= (const MVDirection &right)
	Addition and subtraction.
MVDirection	operator+ (const MVDirection &right) const
MVDirection &	operator-= (const MVDirection &right)
MVDirection	operator- (const MVDirection &right) const
virtual uInt	type () const
	Tell me your type.
virtual void	adjust ()
	Adjust the direction cosines to a length of 1.
virtual void	adjust (Double &res)
	Adjust the direction cosines to a length of 1 and return the length value.
virtual MeasValue *	clone () const
	Re-adjust : taken from MVPosition.
Vector< Double >	get () const
	Generate a 2-vector of angles (in rad).
Double	getLat () const
	Get the latitude angle (rad).
Quantity	getLat (const Unit &unit) const
	and with specified units
Double	positionAngle (const MVPosition &other) const
	Get the position angle between the directions.
Double	positionAngle (const MVDirection &other) const
	Get the position angle between the directions.
Quantity	positionAngle (const MVPosition &other, const Unit &unit) const
Quantity	positionAngle (const MVDirection &other, const Unit &unit) const
Double	separation (const MVPosition &other) const
	Get the angular separation between two directions.
Double	separation (const MVDirection &other) const
	Get the angular separation between two directions.
Quantity	separation (const MVPosition &other, const Unit &unit) const
Quantity	separation (const MVDirection &other, const Unit &unit) const
MVDirection	crossProduct (const MVDirection &other) const
	Produce the cross product.
virtual Vector< Quantum< Double > >	getRecordValue () const
	Get the internal value as a Vector<Quantity>.
virtual Vector< Quantum< Double > >	getXRecordValue () const
virtual Vector< Quantum< Double > >	getTMRecordValue () const
virtual Bool	putValue (const Vector< Quantum< Double > > &in)
	Set the internal value if correct values and dimensions.
void	setAngle (Double angle0, Double angle1)
	Set the internal value, using the longitude and latitude (in rad) given.
void	shift (const Quantum< Double > &lng, const Quantum< Double > &lat, Bool trueAngle=False)
	Shift the direction in longitude (radians if Double) and/or latitude.
void	shift (Double lng, Double lat, Bool trueAngle=False)
void	shiftLongitude (const Quantity &lng, Bool trueAngle=False)
void	shiftLongitude (Double lng, Bool trueAngle=False)
void	shiftLatitude (const Quantum< Double > &lat, Bool trueAngle=False)
void	shiftLatitude (Double lat, Bool trueAngle=False)
void	shift (const MVDirection &shft, Bool trueAngle=False)
void	shiftAngle (const Quantum< Double > &off, const Quantum< Double > &pa)
	Shift over an angle off in the direction pa.
void	shiftAngle (Double off, Double pa)
Static Public Member Functions
static void	assure (const MeasValue &in)

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Detailed Description

Vector of three direction cosines.

Intended use:

Public interface

Review Status

Reviewed By:

tcornwel

Date Reviewed:

1996/02/22

Test programs:

tMeasMath

Prerequisite

• MVPosition
• Vector
• Quantum

Etymology

From Measure, Value and Direction

Synopsis

An MVDirection is a 3-vector of direction cosines. It is based on the MVposition class. The main difference is that the length of the vector will be adjusted (normalised) to a length of 1 in all operations. It can be constructed with:

• MVDirection() creates direction cosines for pole: (0,0,1)
• MVDirection(MVDirection) creates a copy
• MVDirection(Double, Double, Double) creates with specified values and adjust to length of 1.
• MVDirection(Double, Double) creates a MVDirection assuming that the two values are (in radians) angle along 'equator' and towards 'pole'.
• MVDirection(Quantity, Quantity) creates a MVDirection assuming angles as in previous
• MVDirection(Quantum<Vector<Double> >) creates an MVDirection from angle vector, assuming second as zero if not present, and pole if length 0. Assumes a direction cosine if 3 elements
• MVDirection(Vector<Double>) creates an MVDirection with the same restrictions as previous one
• MVDirection(Vector<Quantum<Double> >) creates an MVDirection with the same rstrictions as previous one; but with unit check.

A void adjust() function normalises the vector to a length of 1; a get() returns as a Double 2-vector the angles of the direction cosines; a getAngle() returns a Quantum 2-vector, (uInt) returns the indicated element, and getValue returns the direction cosine vector.
Direction cosines can be added and subtracted: the result will be adjusted to a length of 1.
The multiplication of two direction cosines produces the inner product.
shift() methods are available to shift in angular coordinates. E.g. shift(Quantity(5, "arcsec"), Quantity(-7, "arcsec")) will shift 5 arcsec in longitude, and -7 arcsec in latitude. They have a trueAngle switch to shift in latitude and perpendicular (along a great circle) to it.

Example

See MDirection

Motivation

To aid coordinate transformations

To Do

• check if true shifts can be done faster

Definition at line 106 of file MVDirection.h.

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Constructor & Destructor Documentation

casacore::MVDirection::MVDirection

(

)

Default constructor generates a direction to the pole (i.e.

(0,0,1))

casacore::MVDirection::MVDirection

(

const MVPosition &

other

)

Copy constructor.

casacore::MVDirection::MVDirection

(

Double

in0

)

Constructs with elevation = 0.

casacore::MVDirection::MVDirection

(

const Quantity &

angle0

)

casacore::MVDirection::MVDirection	(	Double	in0,
		Double	in1,
		Double	in2
	)

Creates a specified vector.

casacore::MVDirection::MVDirection	(	Double	angle0,
		Double	angle1
	)

Creates the direction cosines from specified angles along equator (azimuth) and towards pole (,elevation).

casacore::MVDirection::MVDirection	(	const Quantity &	angle0,
		const Quantity &	angle1
	)

Creates the direction cosines from specified angles.

Thrown Exceptions

• AipsError if quantities not in angle format

casacore::MVDirection::MVDirection

(

const Quantum< Vector< Double > > &

angle

)

If not enough angles: pole (=(0,0,1)) assumed (if none), or elevation =0 (if 1); direction cosines assumed (if 3).

Thrown Exceptions

• AipsError if more than 3 values or incorrect units

casacore::MVDirection::MVDirection

(

const Vector< Double > &

other

)

Create from Vector.

Assumes angles if less than or equal than 2 elements. Assumes direction cosines if 3 elements.

Thrown Exceptions

• AipsError if more than 3 elements

casacore::MVDirection::MVDirection

(

const Vector< Quantity > &

other

)

casacore::MVDirection::~MVDirection

(

)

Destructor.

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Member Function Documentation

virtual void casacore::MVDirection::adjust

(

Double &

res

)

[virtual]

Adjust the direction cosines to a length of 1 and return the length value.

Reimplemented from casacore::MVPosition.

virtual void casacore::MVDirection::adjust

(

)

[virtual]

Adjust the direction cosines to a length of 1.

Reimplemented from casacore::MVPosition.

static void casacore::MVDirection::assure

(

const MeasValue &

in

)

[static]

Reimplemented from casacore::MVPosition.

virtual MeasValue* casacore::MVDirection::clone

(

)

const [virtual]

Re-adjust : taken from MVPosition.

Clone data

Reimplemented from casacore::MVPosition.

MVDirection casacore::MVDirection::crossProduct

(

const MVDirection &

other

)

const

Produce the cross product.

Reimplemented from casacore::MVPosition.

Vector<Double> casacore::MVDirection::get

(

)

const

Generate a 2-vector of angles (in rad).

Reimplemented from casacore::MVPosition.

Quantity casacore::MVDirection::getLat

(

const Unit &

unit

)

const

and with specified units

Reimplemented from casacore::MVPosition.

Double casacore::MVDirection::getLat

(

)

const

Get the latitude angle (rad).

Reimplemented from casacore::MVPosition.

virtual Vector<Quantum<Double> > casacore::MVDirection::getRecordValue

(

)

const [virtual]

Get the internal value as a Vector<Quantity>.

Usable in records. The getXRecordValue() gets additional information for records. Note that the Vectors could be empty.

Reimplemented from casacore::MVPosition.

virtual Vector<Quantum<Double> > casacore::MVDirection::getTMRecordValue

(

)

const [virtual]

Reimplemented from casacore::MVPosition.

virtual Vector<Quantum<Double> > casacore::MVDirection::getXRecordValue

(

)

const [virtual]

Reimplemented from casacore::MVPosition.

MVDirection casacore::MVDirection::operator+

(

const MVDirection &

right

)

const

Reimplemented from casacore::MVPosition.

MVDirection& casacore::MVDirection::operator+=

(

const MVDirection &

right

)

Addition and subtraction.

Reimplemented from casacore::MVPosition.

MVDirection casacore::MVDirection::operator-

(

const MVDirection &

right

)

const

Reimplemented from casacore::MVPosition.

MVDirection& casacore::MVDirection::operator-=

(

const MVDirection &

right

)

Reimplemented from casacore::MVPosition.

MVDirection& casacore::MVDirection::operator=

(

const MVDirection &

other

)

Copy assignment.

Reimplemented from casacore::MVPosition.

Quantity casacore::MVDirection::positionAngle	(	const MVDirection &	other,
		const Unit &	unit
	)			const

Reimplemented from casacore::MVPosition.

Quantity casacore::MVDirection::positionAngle	(	const MVPosition &	other,
		const Unit &	unit
	)			const

Double casacore::MVDirection::positionAngle

(

const MVDirection &

other

)

const

Get the position angle between the directions.

I.e. the angle between the direction from one to the pole, and from one to the other.

Reimplemented from casacore::MVPosition.

Double casacore::MVDirection::positionAngle

(

const MVPosition &

other

)

const

Get the position angle between the directions.

I.e. the angle between the direction from one to the pole, and from one to the other.

virtual Bool casacore::MVDirection::putValue

(

const Vector< Quantum< Double > > &

in

)

[virtual]

Set the internal value if correct values and dimensions.

Reimplemented from casacore::MVPosition.

Quantity casacore::MVDirection::separation	(	const MVDirection &	other,
		const Unit &	unit
	)			const

Reimplemented from casacore::MVPosition.

Quantity casacore::MVDirection::separation	(	const MVPosition &	other,
		const Unit &	unit
	)			const

Double casacore::MVDirection::separation

(

const MVDirection &

other

)

const

Get the angular separation between two directions.

Reimplemented from casacore::MVPosition.

Double casacore::MVDirection::separation

(

const MVPosition &

other

)

const

Get the angular separation between two directions.

void casacore::MVDirection::setAngle	(	Double	angle0,
		Double	angle1
	)

Set the internal value, using the longitude and latitude (in rad) given.

void casacore::MVDirection::shift	(	const MVDirection &	shft,
		Bool	trueAngle = False
	)

void casacore::MVDirection::shift	(	Double	lng,
		Double	lat,
		Bool	trueAngle = False
	)

void casacore::MVDirection::shift	(	const Quantum< Double > &	lng,
		const Quantum< Double > &	lat,
		Bool	trueAngle = False
	)

Shift the direction in longitude (radians if Double) and/or latitude.

If the trueAngle switch is True, the longitude shift will be in angular units perpendicular to the direction to the pole at the shifted latitude, along a great circle.

void casacore::MVDirection::shiftAngle	(	Double	off,
		Double	pa
	)

void casacore::MVDirection::shiftAngle	(	const Quantum< Double > &	off,
		const Quantum< Double > &	pa
	)

Shift over an angle off in the direction pa.

pa is measured from North, in the direction of increasing longitude.

void casacore::MVDirection::shiftLatitude	(	Double	lat,
		Bool	trueAngle = False
	)

void casacore::MVDirection::shiftLatitude	(	const Quantum< Double > &	lat,
		Bool	trueAngle = False
	)

void casacore::MVDirection::shiftLongitude	(	Double	lng,
		Bool	trueAngle = False
	)

void casacore::MVDirection::shiftLongitude	(	const Quantity &	lng,
		Bool	trueAngle = False
	)

virtual uInt casacore::MVDirection::type

(

)

const [virtual]

Tell me your type.

Reimplemented from casacore::MVPosition.

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

• casacore/casa/Quanta/MVDirection.h