Class CylindricalEqualArea
java.lang.Object
org.apache.sis.io.wkt.FormattableObject
org.apache.sis.referencing.operation.transform.AbstractMathTransform
org.apache.sis.referencing.operation.transform.AbstractMathTransform2D
org.apache.sis.referencing.operation.projection.NormalizedProjection
org.apache.sis.referencing.operation.projection.AuthalicConversion
org.apache.sis.referencing.operation.projection.CylindricalEqualArea
- All Implemented Interfaces:
Serializable
,Parameterized
,LenientComparable
,org.opengis.referencing.operation.MathTransform
,org.opengis.referencing.operation.MathTransform2D
- Direct Known Subclasses:
CylindricalEqualArea.Spherical
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
- Version:
- 1.2
- See Also:
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Nested Class Summary
Nested ClassesModifier and TypeClassDescriptionprivate static final class
Provides the transform equations for the spherical case of the Cylindrical Equal Area projection.private static enum
The variants of the projection based on the name and identifier of the given operation method.Nested classes/interfaces inherited from class org.apache.sis.referencing.operation.projection.NormalizedProjection
NormalizedProjection.ParameterRole
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate static final long
For cross-version compatibility.private final CylindricalEqualArea.Variant
The type of Cylindrical Equal Area projection.Fields inherited from class org.apache.sis.referencing.operation.projection.AuthalicConversion
isSpherical, qmPolar
Fields inherited from class org.apache.sis.referencing.operation.projection.NormalizedProjection
ANGULAR_TOLERANCE, context, eccentricity, eccentricitySquared, ITERATION_TOLERANCE, LARGE_LONGITUDE_LIMIT, MAXIMUM_ITERATIONS, POLAR_AREA_LIMIT
Fields inherited from class org.apache.sis.referencing.operation.transform.AbstractMathTransform2D
DIMENSION
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Constructor Summary
ConstructorsModifierConstructorDescription(package private)
Creates a new projection initialized to the same parameters than the given one.private
CylindricalEqualArea
(Initializer initializer) Work around for RFE #4093999 in Sun's bug database ("Relax constraint on placement of this()/super() call in constructors").CylindricalEqualArea
(org.opengis.referencing.operation.OperationMethod method, Parameters parameters) Creates a Cylindrical Equal Area projection from the given parameters. -
Method Summary
Modifier and TypeMethodDescriptionorg.opengis.referencing.operation.MathTransform
createMapProjection
(org.opengis.referencing.operation.MathTransformFactory factory) Returns the sequence of normalization →this
→ denormalization transforms as a whole.private static Initializer
initializer
(org.opengis.referencing.operation.OperationMethod method, Parameters parameters) Work around for RFE #4093999 in Sun's bug database ("Relax constraint on placement of this()/super() call in constructors").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).org.opengis.referencing.operation.Matrix
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 org.apache.sis.referencing.operation.projection.AuthalicConversion
dqm_dφ, qm, sinβ, φ
Methods inherited from class org.apache.sis.referencing.operation.projection.NormalizedProjection
completeWithWraparound, computeHashCode, delegate, equals, getContextualParameters, getInternalParameterNames, getInternalParameterValues, getParameterDescriptors, getParameterValues, getWraparoundLongitude, inverse, tryConcatenate, tryConcatenate, variant
Methods inherited from class org.apache.sis.referencing.operation.transform.AbstractMathTransform2D
createTransformedShape, derivative, getSourceDimensions, getTargetDimensions, transform
Methods inherited from class org.apache.sis.referencing.operation.transform.AbstractMathTransform
derivative, equals, formatTo, getDomain, hashCode, isIdentity, transform, transform, transform, transform
Methods inherited from class org.apache.sis.io.wkt.FormattableObject
print, toString, toString, toWKT
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
Methods inherited from interface org.opengis.referencing.operation.MathTransform
derivative, isIdentity, toWKT, transform, transform, transform, transform
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Field Details
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serialVersionUID
private static final long serialVersionUIDFor cross-version compatibility.- See Also:
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variant
The type of Cylindrical Equal Area projection. Possible values are:CylindricalEqualArea.Variant.ELLIPSOIDAL
if this projection is a default variant.CylindricalEqualArea.Variant.SPHERICAL
if this projection is the "Lambert Cylindrical Equal Area (Spherical)" case, in which case the semi-major and semi-minor axis lengths should be replaced by the authalic radius (this replacement is performed by theInitializer
constructor).
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Constructor Details
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CylindricalEqualArea
public CylindricalEqualArea(org.opengis.referencing.operation.OperationMethod method, Parameters parameters) 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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CylindricalEqualArea
Work around for RFE #4093999 in Sun's bug database ("Relax constraint on placement of this()/super() call in constructors"). -
CylindricalEqualArea
CylindricalEqualArea(CylindricalEqualArea other) Creates a new projection initialized to the same parameters than the given one.
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Method Details
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initializer
@Workaround(library="JDK", version="1.7") private static Initializer initializer(org.opengis.referencing.operation.OperationMethod method, Parameters parameters) Work around for RFE #4093999 in Sun's bug database ("Relax constraint on placement of this()/super() call in constructors"). -
createMapProjection
public org.opengis.referencing.operation.MathTransform createMapProjection(org.opengis.referencing.operation.MathTransformFactory factory) throws org.opengis.util.FactoryException 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:
org.opengis.util.FactoryException
- if an error occurred while creating a transform.- See Also:
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transform
public org.opengis.referencing.operation.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 org.opengis.referencing.operation.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 interfaceorg.opengis.referencing.operation.MathTransform
- 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:
org.opengis.referencing.operation.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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