Class CylindricalEqualArea
Object
FormattableObject
AbstractMathTransform
AbstractMathTransform2D
NormalizedProjection
CylindricalEqualArea
- All Implemented Interfaces:
Serializable
,Parameterized
,LenientComparable
,MathTransform
,MathTransform2D
Cylindrical Equal Area projection (EPSG codes 9834, 9835).
This is the simplest equal-area projection.
This projection has various names depending on its standard parallel:
Name | Standard parallel |
---|---|
Lambert cylindrical equal-area | 0° |
Behrmann cylindrical equal-area | 30° |
Gall orthographic | 45° |
Balthasart | 50° |
Description
The parallels and the meridians are straight lines and cross at right angles. The scale is true along standard parallels, but distortion increase greatly at other locations. Distortions are so great that there is little use of this projection for world mapping purposes. However, this projection may be useful for computing areas.- Since:
- 0.8
- See Also:
Defined in the sis-referencing
module
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Nested Class Summary
Nested classes/interfaces inherited from class NormalizedProjection
NormalizedProjection.ParameterRole
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Field Summary
Fields inherited from class NormalizedProjection
eccentricity, eccentricitySquared
Fields inherited from class AbstractMathTransform2D
DIMENSION
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Constructor Summary
ConstructorsConstructorDescriptionCylindricalEqualArea
(OperationMethod method, Parameters parameters) Creates a Cylindrical Equal Area projection from the given parameters. -
Method Summary
Modifier and TypeMethodDescriptionReturns the sequence of normalization →this
→ denormalization transforms as a whole.protected void
inverseTransform
(double[] srcPts, int srcOff, double[] dstPts, int dstOff) Converts the specified (x,y) coordinates and stores the result indstPts
(angles in radians).transform
(double[] srcPts, int srcOff, double[] dstPts, int dstOff, boolean derivate) Projects the specified (λ,φ) coordinates (units in radians) and stores the result indstPts
.void
transform
(double[] srcPts, int srcOff, double[] dstPts, int dstOff, int numPts) Converts a list of coordinate tuples.Methods inherited from class NormalizedProjection
computeHashCode, equals, getContextualParameters, getParameterDescriptors, getParameterValues, inverse, tryConcatenate
Methods inherited from class AbstractMathTransform2D
createTransformedShape, derivative, getSourceDimensions, getTargetDimensions, transform
Methods inherited from class AbstractMathTransform
derivative, equals, formatTo, getDomain, hashCode, isIdentity, transform, transform, transform, transform
Methods inherited from class FormattableObject
print, toString, toString, toWKT
Methods inherited from class Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
Methods inherited from interface MathTransform
derivative, isIdentity, toWKT, transform, transform, transform, transform
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Constructor Details
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CylindricalEqualArea
Creates a Cylindrical Equal Area projection from the given parameters.- Parameters:
method
- Description of the projection parameters.parameters
- The parameter values of the projection to create.
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Method Details
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createMapProjection
Returns the sequence of normalization →this
→ denormalization transforms as a whole. The transform returned by this method expects (longitude, latitude) coordinates in degrees and returns (x,y) coordinates in metres.The non-linear part of the returned transform will be
this
transform, except if the ellipsoid is spherical. In the latter case,this
transform may be replaced by a simplified implementation.- Overrides:
createMapProjection
in classNormalizedProjection
- Parameters:
factory
- the factory to use for creating the transform.- Returns:
- the map projection from (λ,φ) to (x,y) coordinates.
- Throws:
FactoryException
- if an error occurred while creating a transform.- See Also:
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transform
public Matrix transform(double[] srcPts, int srcOff, double[] dstPts, int dstOff, boolean derivate) throws ProjectionException Projects the specified (λ,φ) coordinates (units in radians) and stores the result indstPts
. In addition, opportunistically computes the projection derivative ifderivate
istrue
. The results must be multiplied by the denormalization matrix before to get linear distances.- Specified by:
transform
in classNormalizedProjection
- Parameters:
srcPts
- the array containing the source point coordinates, as (longitude, latitude) angles in radians.srcOff
- the offset of the single coordinate tuple to be converted in the source array.dstPts
- the array into which the converted coordinates is returned (may be the same thansrcPts
). Coordinates will be expressed in a dimensionless unit, as a linear distance on a unit sphere or ellipse.dstOff
- the offset of the location of the converted coordinates that is stored in the destination array.derivate
-true
for computing the derivative, orfalse
if not needed.- Returns:
- the matrix of the projection derivative at the given source position,
or
null
if thederivate
argument isfalse
. - Throws:
ProjectionException
- if the coordinates cannot be converted.- See Also:
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transform
public void transform(double[] srcPts, int srcOff, double[] dstPts, int dstOff, int numPts) throws TransformException Converts a list of coordinate tuples. This method performs the same calculation than abovetransform(double[], int, double[], int, boolean)
method, but is overridden for efficiency.- Specified by:
transform
in interfaceMathTransform
- Overrides:
transform
in classAbstractMathTransform
- Parameters:
srcPts
- the array containing the source point coordinates.srcOff
- the offset to the first point to be transformed in the source array.dstPts
- the array into which the transformed point coordinates are returned. May be the same thansrcPts
.dstOff
- the offset to the location of the first transformed point that is stored in the destination array.numPts
- the number of point objects to be transformed.- Throws:
TransformException
- if a point cannot be converted.
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inverseTransform
protected void inverseTransform(double[] srcPts, int srcOff, double[] dstPts, int dstOff) throws ProjectionException Converts the specified (x,y) coordinates and stores the result indstPts
(angles in radians).- Specified by:
inverseTransform
in classNormalizedProjection
- Parameters:
srcPts
- the array containing the source point coordinates, as linear distance on a unit sphere or ellipse.srcOff
- the offset of the point to be converted in the source array.dstPts
- the array into which the converted point coordinates is returned (may be the same thansrcPts
). Coordinates will be (longitude, latitude) angles in radians.dstOff
- the offset of the location of the converted point that is stored in the destination array.- Throws:
ProjectionException
- if the point cannot be converted.
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