Package org.apache.sis.referencing.operation.transform

package org.apache.sis.referencing.operation.transform

Conversions or transformations of multi-dimensional coordinate tuples. Math­Transform provides a single API for coordinate conversions or transformations, including map projections. Each Math­Transform instances can:

• transform a single point,
• transform efficiently an array of coordinates,
• transform a Java2D Shape (Math­Transform2D only),
• compute the transform derivative at a location (for advanced users),
• be concatenated in a conversion or transformation chain.

Math­Transform are truly n-dimensional, but specialized implementations for 1D and 2D cases are provided for performance reasons or for inter-operability with Java2D. In the 2D case, Apache SIS provides instances of the standard Affine­Transform class when possible.

This package does not include map projections, which are a special kind of transforms defined in their own internal package.

Creating math transforms

Math­Transform instances can be created either directly or indirectly. The recommended way is the indirect one: first find the coordinate operation (generally from a pair of source and target CRS), then invoke Coordinate­Operation.get­Math­Transform(). However, sophisticated users can also create math transforms explicitly from a group of parameter values using the math transform factory.

Non-spatial coordinates

Math­Transform usually performs conversions or transformations from points given in a source coordinate reference system to coordinate values for the same points in the target coordinate reference system. However, the conversions are not necessarily between CRS; a Math­Transform can also be used for converting the sample values in a raster for example. Such kind of transforms are named transfer functions.

Since:

0.5

Related Packages

Package	Description
org.apache.sis.referencing.operation	Relationship between any two Coordinate Reference Systems (CRS).
org.apache.sis.referencing.operation.builder	Helper classes for creating Math Transforms from a set of points.
org.apache.sis.referencing.operation.matrix	Matrix implementations for spatiotemporal referencing.

Class	Description
AbstractMathTransform	Provides a default implementation for most methods required by the Math­Transform interface.
AbstractMathTransform.Inverse	Base class for implementations of inverse math transforms.
AbstractMathTransform1D	Base class for math transforms that are known to be one-dimensional in all cases.
AbstractMathTransform1D.Inverse	Base class for implementation of inverse math transforms.
AbstractMathTransform2D	Base class for math transforms that are known to be two-dimensional in all cases.
AbstractMathTransform2D.Inverse	Base class for implementation of inverse math transforms.
ContextualParameters	The parameters that describe a sequence of normalize → non-linear kernel → denormalize transforms as a whole.
ContextualParameters.MatrixRole	Whether a matrix is used for normalization or denormalization before or after a non-linear operation.
DatumShiftTransform	Transforms between two CRS (usually geographic) based on different datum.
DefaultMathTransformFactory	Low level factory for creating math transforms.
DefaultMathTransformFactory.Context	Deprecated, for removal: This API element is subject to removal in a future version. Replaced by Default­Math­Transform­Factory.builder(String).
DomainDefinition	Specification about how to estimate a domain of validity for transforms.
EllipsoidToCentricTransform	Transform from two- or three- dimensional ellipsoidal coordinates to geocentric or planetocentric coordinates.
EllipsoidToCentricTransform.TargetType	Whether the output coordinate system is Cartesian or spherical.
EllipsoidToRadiusTransform	Conversion of spherical coordinates from (λ,Ω) to (λ,Ω,R) with points assumed to be on an ellipsoid surface.
InterpolatedGeocentricTransform	Transforms between two geographic CRS by performing geocentric translations interpolated from a grid file.
InterpolatedTransform	Transforms between two CRS by performing translations interpolated from a grid file.
IterationStrategy	Strategy for iterating over the point arrays given to Abstract­Math­Transform.transform(…) methods.
LinearTransform	A usually affine, or otherwise a projective transform, which convert coordinates using only linear equations.
MathTransformBuilder	Builder of a parameterized math transform using a method identified by a name or code.
MathTransformProvider	An object capable to create Math­Transform instances from given parameter values.
MathTransformProvider.Context	The parameter values that define the transform to create, together with its context.
MathTransforms	Utility methods creating or working on Math­Transform instances.
MolodenskyTransform	Two- or three-dimensional datum shift using the (potentially abridged) Molodensky transformation.
PassThroughTransform	Transform which passes through a subset of coordinates to another transform.
PoleRotation	Computes latitudes and longitudes on a sphere where the south pole has been moved to given geographic coordinates.
TransferFunction	The function converting raster sample values to geophysics values.
TransformJoiner	Handler used during concatenations for simplifying a single transform with its neighbor transforms.
TransformSeparator	Extracts a sub-transform from a given Math­Transform and source or target dimension indices.
WraparoundTransform	Enforces coordinate values in the range of a wraparound axis (typically longitude).