Class ObliqueStereographic
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.ObliqueStereographic
- All Implemented Interfaces:
Serializable
,Parameterized
,LenientComparable
,org.opengis.referencing.operation.MathTransform
,org.opengis.referencing.operation.MathTransform2D
- Direct Known Subclasses:
ObliqueStereographic.Spherical
Oblique Stereographic projection (EPSG code 9809).
See the following references for an overview:
Description
The directions starting from the central point are true, but the areas and the lengths become increasingly deformed as one moves away from the center. This projection is frequently used for mapping polar areas, but can also be used for other limited areas centered on a point.This projection involves two steps: first a conversion of geodetic coordinates to conformal coordinates (i.e. latitudes and longitudes on a conformal sphere), then a spherical stereographic projection. For this reason this projection method is sometimes known as "Double Stereographic".
Note:
there is another method known as "Oblique Stereographic Alternative" or sometimes just
"Stereographic". That alternative uses a simplified conversion computing the conformal latitude
of each point on the ellipsoid. Both methods are considered valid but produce slightly different results.
For this reason EPSG considers them as different projection methods.
- Since:
- 0.7
- 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 Oblique Stereographic projection.Nested classes/interfaces inherited from class org.apache.sis.referencing.operation.projection.NormalizedProjection
NormalizedProjection.ParameterRole
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Field Summary
FieldsModifier and TypeFieldDescriptionprivate final double
Parameters used in the conformal sphere definition.(package private) final double
Conformal latitude of origin (χ₀), together with its sine and cosine.private final double
Parameters used in the inverse projection.private final double
Parameters used in the inverse projection.private final double
Parameters used in the conformal sphere definition.private static final long
For cross-version compatibility.(package private) final double
Conformal latitude of origin (χ₀), together with its sine and cosine.(package private) final double
Conformal latitude of origin (χ₀), together with its sine and cosine.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
ConstructorsModifierConstructorDescriptionprivate
ObliqueStereographic
(Initializer initializer) Work around for RFE #4093999 in Sun's bug database ("Relax constraint on placement of this()/super() call in constructors").(package private)
Creates a new projection initialized to the same parameters than the given one.ObliqueStereographic
(org.opengis.referencing.operation.OperationMethod method, Parameters parameters) Creates an Oblique Stereographic 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 twoObliqueStereographic
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 twoObliqueStereographic
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 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 and stores the result indstPts
.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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χ0
final double χ0Conformal latitude of origin (χ₀), together with its sine and cosine. In the spherical case, χ₀ = φ₀ (the geodetic latitude of origin). -
sinχ0
final double sinχ0Conformal latitude of origin (χ₀), together with its sine and cosine. In the spherical case, χ₀ = φ₀ (the geodetic latitude of origin). -
cosχ0
final double cosχ0Conformal latitude of origin (χ₀), together with its sine and cosine. In the spherical case, χ₀ = φ₀ (the geodetic latitude of origin). -
c
private final double c -
n
private final double n -
g
private final double gParameters used in the inverse projection. More precisely g and h are used to compute intermediate parameters i and j, which are themselves used to compute conformal latitude and longitude. -
h
private final double hParameters used in the inverse projection. More precisely g and h are used to compute intermediate parameters i and j, which are themselves used to compute conformal latitude and longitude.
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Constructor Details
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ObliqueStereographic
public ObliqueStereographic(org.opengis.referencing.operation.OperationMethod method, Parameters parameters) Creates an Oblique Stereographic projection from the given parameters. Themethod
argument can be the description of one of the following:- "Oblique Stereographic", also known as "Roussilhe".
- Parameters:
method
- description of the projection parameters.parameters
- the parameter values of the projection to create.
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ObliqueStereographic
Work around for RFE #4093999 in Sun's bug database ("Relax constraint on placement of this()/super() call in constructors"). -
ObliqueStereographic
ObliqueStereographic(ObliqueStereographic 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 twoObliqueStereographic
projections or formatting them in debug mode.We could report any of the internal parameters. But since they are all derived from φ₀ and the eccentricity and since the eccentricity is already reported by the super-class, we report only χ₀ as a representative of the internal parameters.
- 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 twoObliqueStereographic
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 (Λ,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 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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