IlvCylindricalEqualAreaProjection Class Reference

This class defines the Cylindrical Equal Area projection. More...

#include <ilviews/maps/projection/cyleqare.h>

Inheritance diagram for IlvCylindricalEqualAreaProjection:

List of all members.

Public Member Functions
	IlvCylindricalEqualAreaProjection (IlDouble latitudeOfTrueScale=0.)
	Initializes an instance of the IlvCylindricalEqualAreaProjection class and sets the latitude of the true scale to the specified value.
virtual IlvProjection *	copy () const
	Returns a copy of the projection. It must be overridden in each subclass.
virtual IlvProjectionClassInfo *	getClassInfo () const
	Returns the class information for the projection.
IlDouble	getLatitudeOfTrueScale () const
	Returns the latitude of the true scale.
virtual IlvMapsError	setEllipsoid (const IlvEllipsoid &ellipsoid)
	Sets the ellipsoid used for the projection.
void	setLatitudeOfTrueScale (IlDouble latitudeOfTrueScale)
	Sets the latitude of the true scale.
virtual void	write (IlvOutputFile &) const
	Saves the parameters of a projection to the specified output file.
Static Public Member Functions
static IlvProjectionClassInfo *	ClassInfo ()
	Returns the class information of the class.
static IlvClassInfo **	ClassInfoRef ()
	Returns the address of the class information of the class.
Protected Member Functions
virtual IlvMapsError	eForward (IlvCoordinate &ll) const
	Must be redefined in subclasses to implement the projection for a non spherical ellipsoid.
virtual IlvMapsError	eInverse (IlvCoordinate &xy) const
	Implements the inverse projection for a non spherical ellipsoid.
virtual IlvMapsError	sForward (IlvCoordinate &ll) const
	Must be redefined in subclasses to implement the projection for a sphere.
virtual IlvMapsError	sInverse (IlvCoordinate &xy) const
	Must be redefined in subclasses to implement the inverse projection for a sphere.

---

Detailed Description

This class defines the Cylindrical Equal Area projection.

A cylindrical projection is obtained by wrapping a large, flat plane around the globe to form a cylinder. The Cylindrical Equal Area projection is also known as:

• Lambert Cylindric Equal Area
• Behrmann
• Gall Orthographic
• Peters

This class applies both to spherical and non-spherical ellipsoids and implements an inverse function. This projection is Equal Area.

Cylindrical Equal Area Projection

Library: ilvmaps

---

Constructor & Destructor Documentation

IlvCylindricalEqualAreaProjection::IlvCylindricalEqualAreaProjection

(

IlDouble

latitudeOfTrueScale = 0.

)

Initializes an instance of the IlvCylindricalEqualAreaProjection class and sets the latitude of the true scale to the specified value.

Parameters:

latitudeOfTrueScale

The latitude of the true scale.

---

Member Function Documentation

static IlvProjectionClassInfo* IlvCylindricalEqualAreaProjection::ClassInfo

(

)

[static]

Returns the class information of the class.

This static function is also available for the subclasses of IlvProjection.

Returns:

The IlvProjectionClassInfo of the class.

Reimplemented from IlvProjection.

static IlvClassInfo** IlvCylindricalEqualAreaProjection::ClassInfoRef

(

)

[static]

Returns the address of the class information of the class.

This static function is also available for the subclasses of IlvProjection.

Returns:

The address of the IlvProjectionClassInfo of the class.

Reimplemented from IlvProjection.

virtual IlvProjection* IlvCylindricalEqualAreaProjection::copy

(

)

const [virtual]

Returns a copy of the projection. It must be overridden in each subclass.

Returns:

The copy of the object.

Implements IlvProjection.

virtual IlvMapsError IlvCylindricalEqualAreaProjection::eForward

(

IlvCoordinate &

ll

)

const [protected, virtual]

Must be redefined in subclasses to implement the projection for a non spherical ellipsoid.

The default implementation returns IlvProjection::UnsupportedFeatureError().

Parameters:

ll

Contains the longitude and latitude coordinates in radian (x = longitude, y = latitude).

Returns:

An error code.

Reimplemented from IlvProjection.

virtual IlvMapsError IlvCylindricalEqualAreaProjection::eInverse

(

IlvCoordinate &

xy

)

const [protected, virtual]

Implements the inverse projection for a non spherical ellipsoid.

The default implementation returns IlvProjection::UnsupportedFeatureError().

Parameters:

xy

Contains the Cartesian coordinates to inverse.

Returns:

An error code.

Reimplemented from IlvProjection.

virtual IlvProjectionClassInfo* IlvCylindricalEqualAreaProjection::getClassInfo

(

)

const [virtual]

Returns the class information for the projection.

Returns:

The class information for the projection.

Reimplemented from IlvProjection.

IlDouble IlvCylindricalEqualAreaProjection::getLatitudeOfTrueScale

(

)

const

Returns the latitude of the true scale.

Returns:

The latitude of the true scale.

virtual IlvMapsError IlvCylindricalEqualAreaProjection::setEllipsoid

(

const IlvEllipsoid &

ellipsoid

)

[virtual]

Sets the ellipsoid used for the projection.

This virtual member function sets the ellipsoid used for the projection. Most of the projections are initialized with a spherical ellipsoid with a radius of 6,370,997 meters.
This function returns IlvMaps::NoError() if the operation is successful or an error status if you specify a non spherical ellipsoid and your type does not support non spherical.

Parameters:

ellipsoid

The ellipsoid used for the projection.

Returns:

IlvMapsError if the ellipsoid does not match the projection.

Reimplemented from IlvProjection.

void IlvCylindricalEqualAreaProjection::setLatitudeOfTrueScale

(

IlDouble

latitudeOfTrueScale

)

Sets the latitude of the true scale.

Parameters:

latitudeOfTrueScale

The latitude of the true scale.

virtual IlvMapsError IlvCylindricalEqualAreaProjection::sForward

(

IlvCoordinate &

ll

)

const [protected, virtual]

Must be redefined in subclasses to implement the projection for a sphere.

Parameters:

ll

Contains the longitude and latitude coordinates in radian (x = longitude, y = latitude).

Implements IlvProjection.

virtual IlvMapsError IlvCylindricalEqualAreaProjection::sInverse

(

IlvCoordinate &

xy

)

const [protected, virtual]

Must be redefined in subclasses to implement the inverse projection for a sphere.

The default implementation returns IlvProjection::UnsupportedFeatureError().

Parameters:

xy

Contains the Cartesian coordinates to inverse.

Returns:

An error code.

Reimplemented from IlvProjection.

virtual void IlvCylindricalEqualAreaProjection::write

(

IlvOutputFile &

outputFile

)

const [virtual]

Saves the parameters of a projection to the specified output file.

It must be overridden by subclasses of IlvProjection that need to save additional parameters. This function should not be directly called; use the save function instead.

Parameters:

outputFile

The file to write the projection parameters to.

Reimplemented from IlvProjection.