Class ObliqueStereographic
Object
FormattableObject
AbstractMathTransform
AbstractMathTransform2D
NormalizedProjection
ObliqueStereographic
- All Implemented Interfaces:
Serializable
,Parameterized
,LenientComparable
,MathTransform
,MathTransform2D
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
- 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
ConstructorsConstructorDescriptionObliqueStereographic
(OperationMethod method, Parameters parameters) Creates an Oblique Stereographic 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 and stores the result indstPts
.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, 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, transform
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Constructor Details
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ObliqueStereographic
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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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 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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