Class AlbersEqualArea
- All Implemented Interfaces:
Serializable
,Parameterized
,LenientComparable
,org.opengis.referencing.operation.MathTransform
,org.opengis.referencing.operation.MathTransform2D
- Direct Known Subclasses:
AlbersEqualArea.Spherical
The "standard_parallel_2"
parameter is optional and will be given the same value as
"standard_parallel_1"
if not set.
- Since:
- 0.8
- Version:
- 1.3
- See Also:
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Nested Class Summary
Nested ClassesModifier and TypeClassDescription(package private) static final class
Provides the transform equations for the spherical case of the Albers Equal Area projection.Nested classes/interfaces inherited from class org.apache.sis.referencing.operation.projection.NormalizedProjection
NormalizedProjection.ParameterRole
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Field Summary
FieldsModifier and TypeFieldDescription(package private) final double
Internal coefficients for computation, depending only on values of standards parallels.(package private) final double
Internal coefficients for computation, depending only on eccentricity and values of standards parallels.private static final long
For cross-version compatibility.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)
AlbersEqualArea
(AlbersEqualArea other) Creates a new projection initialized to the same parameters than the given one.private
AlbersEqualArea
(Initializer initializer) Work around for RFE #4093999 in Sun's bug database ("Relax constraint on placement of this()/super() call in constructors").AlbersEqualArea
(org.opengis.referencing.operation.OperationMethod method, Parameters parameters) Creates an Albers 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.(package private) final String[]
Returns the names of additional internal parameters which need to be taken in account when comparing twoAlbersEqualArea
projections or formatting them in debug mode.(package private) final double[]
Returns the values of additional internal parameters which need to be taken in account when comparing twoAlbersEqualArea
projections or formatting them in debug mode.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 (θ,φ) result indstPts
.org.opengis.referencing.operation.Matrix
transform
(double[] srcPts, int srcOff, double[] dstPts, int dstOff, boolean derivate) Projects the specified (θ,φ) coordinates and stores the result indstPts
.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, 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, 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, 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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nm
final double nmInternal coefficients for computation, depending only on eccentricity and values of standards parallels. This is defined as n = (m₁² – m₂²) / (α₂ – α₁) in §1.3.13 of IOGP Publication 373-7-2 (april 2015).In Apache SIS implementation, we use modified formulas in which the (1 - ℯ²) factor is omitted in
AuthalicConversion.qm(double)
calculation. Consequently, what we get is a modified value nm which is related to Snyder's n value by n = nm / (1 - ℯ²). The omitted (1 - ℯ²) factor is either taken in account by the (de)normalization matrix, or cancels with other (1 - ℯ²) factors when we develop the formulas.Note that in the spherical case, nm = Snyder's n.
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C
final double CInternal coefficients for computation, depending only on values of standards parallels. This is defined as C = m₁² + (n⋅α₁) in §1.3.13 of IOGP Publication 373-7-2 – Geomatics Guidance Note number 7, part 2 – April 2015.
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Constructor Details
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AlbersEqualArea
public AlbersEqualArea(org.opengis.referencing.operation.OperationMethod method, Parameters parameters) Creates an Albers 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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AlbersEqualArea
Work around for RFE #4093999 in Sun's bug database ("Relax constraint on placement of this()/super() call in constructors"). -
AlbersEqualArea
AlbersEqualArea(AlbersEqualArea 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"). -
getInternalParameterNames
Returns the names of additional internal parameters which need to be taken in account when comparing twoAlbersEqualArea
projections or formatting them in debug mode.- Overrides:
getInternalParameterNames
in classNormalizedProjection
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getInternalParameterValues
final double[] getInternalParameterValues()Returns the values of additional internal parameters which need to be taken in account when comparing twoAlbersEqualArea
projections or formatting them in debug mode.- Overrides:
getInternalParameterValues
in classNormalizedProjection
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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 (θ,φ) coordinates and stores the result indstPts
. In addition, opportunistically computes the projection derivative ifderivate
istrue
. The units of measurement are implementation-specific (see super-class javadoc). 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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inverseTransform
protected void inverseTransform(double[] srcPts, int srcOff, double[] dstPts, int dstOff) throws ProjectionException Converts the specified (x,y) coordinates and stores the (θ,φ) result indstPts
.- 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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