Class MathTransformBuilder
- Direct Known Subclasses:
AdvancedAffineBuilder
,BursaWolfTransformBuilder
,ProjectiveTransformBuilder
,RubberSheetBuilder
Math transform builders create MathTransform
objects for transforming coordinates from a source CRS
(Coordinate Reference System) to a target CRS using empirical parameters.
Usually, one of those CRS is a geographic or projected one with
a well known relationship to the earth. The other CRS is often an engineering or
image one tied to some ship. For example a remote sensing image before
georectification may be referenced by an image CRS.
The math transform from source CRS to target CRS is calculated byDesign note: It is technically possible to reference such remote sensing images with a CRS derived from the geographic or projected CRS, where the conversion from base is the math transform computed by this builder. Such approach is advantageous for coordinate operation factory implementations, since they can determine the operation just by inspection of the
DerivedCRS
instance. However this is conceptually incorrect sinceDerivedCRS
can be related to an other CRS only through conversions, which by definition are accurate up to rounding errors. The operations created by math transform builders are rather transformations, which can't be used forDerivedCRS
creation.
MathTransformBuilder
from a set of mapped positions in both CRS.
Subclasses must implement at least the getMinimumPointCount()
and computeMathTransform()
methods.
- Since:
- 2.4
- Author:
- Jan Jezek, Martin Desruisseaux
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Field Summary
FieldsModifier and TypeFieldDescriptionprotected final MathTransformFactory
The factory to use for creatingmath transform
instances. -
Constructor Summary
ConstructorsConstructorDescriptionCreates a builder with the default factories.MathTransformBuilder
(Hints hints) Creates a builder from the specified hints. -
Method Summary
Modifier and TypeMethodDescriptionprotected abstract MathTransform
Calculates the math transform immediately.Class<? extends CoordinateSystem>
Returns the required coordinate system type.int
Returns statistics about the errors.Returns the list of mapped positions.final MathTransform
Returns the calculated math transform.abstract int
Returns the minimum number of points required by this builder.getName()
Returns the name for the transformation to be created by this builder.Returns the coordinate reference system for thesource points
.Position[]
Returns the source points.Returns the coordinate reference system for thetarget points
.Position[]
Returns the target points.Returns the coordinate operation wrapping the calculated math transform.void
printPoints
(Writer out, Locale locale) Prints a table of all source and target points stored in this builder.void
setMappedPositions
(List<MappedPosition> positions) Set the list of mapped positions.void
setSourcePoints
(Position... points) Convenience method setting the source points in mapped positions.void
setTargetPoints
(Position... points) Convenience method setting the target points in mapped positions.toString()
Returns a string representation of this builder.
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Field Details
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mtFactory
The factory to use for creatingmath transform
instances.
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Constructor Details
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MathTransformBuilder
public MathTransformBuilder()Creates a builder with the default factories. -
MathTransformBuilder
Creates a builder from the specified hints.
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Method Details
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getName
Returns the name for the transformation to be created by this builder. -
getMinimumPointCount
public abstract int getMinimumPointCount()Returns the minimum number of points required by this builder. This minimum depends on the algorithm used. For example affine transform builders require at least 3 points, while similar transform builders requires only 2 points. -
getDimension
public int getDimension() -
getMappedPositions
Returns the list of mapped positions. -
setMappedPositions
public void setMappedPositions(List<MappedPosition> positions) throws IllegalArgumentException, MismatchedDimensionException, MismatchedReferenceSystemException Set the list of mapped positions.- Throws:
IllegalArgumentException
- if the list doesn't have the expected number of points.MismatchedDimensionException
- if some points doesn't have the expected number of dimensions.MismatchedReferenceSystemException
- if CRS is not the same for all points.
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getSourcePoints
Returns the source points. This convenience method extracts those points from the mapped positions. -
setSourcePoints
public void setSourcePoints(Position... points) throws IllegalArgumentException, MismatchedDimensionException, MismatchedReferenceSystemException Convenience method setting the source points in mapped positions.- Parameters:
points
- The source points.- Throws:
IllegalArgumentException
- if the list doesn't have the expected number of points.MismatchedDimensionException
- if some points doesn't have the expected number of dimensions.MismatchedReferenceSystemException
- if CRS is not the same for all points.
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getTargetPoints
Returns the target points. This convenience method extracts those points from the mapped positions. -
setTargetPoints
public void setTargetPoints(Position... points) throws IllegalArgumentException, MismatchedDimensionException, MismatchedReferenceSystemException Convenience method setting the target points in mapped positions.- Parameters:
points
- The target points.- Throws:
IllegalArgumentException
- if the list doesn't have the expected number of points.MismatchedDimensionException
- if some points doesn't have the expected number of dimensions.MismatchedReferenceSystemException
- if CRS is not the same for all points.
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printPoints
Prints a table of all source and target points stored in this builder.- Parameters:
out
- The output device where to print all points.locale
- The locale, ornull
for the default.- Throws:
IOException
- if an error occured while printing.
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getSourceCRS
Returns the coordinate reference system for thesource points
. This method determines the CRS as below:- If at least one source points has a CRS, then this CRS is selected as the source one and returned.
- If no source point has a CRS, then this method creates an engineering CRS using the same coordinate system than the one used by the target CRS.
- Throws:
FactoryException
- if the CRS can't be created.
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getTargetCRS
Returns the coordinate reference system for thetarget points
. This method determines the CRS as below:- If at least one target points has a CRS, then this CRS is selected as the target one and returned.
- If no target point has a CRS, then this method creates an engineering CRS using the same coordinate system than the one used by the source CRS.
- Throws:
FactoryException
- if the CRS can't be created.
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getCoordinateSystemType
Returns the required coordinate system type. The default implementation returnsCoordinateSystem.class
, which means that every kind of coordinate system is legal. Some subclasses will restrict to cartesian CS. -
getErrorStatistics
Returns statistics about the errors. The errors are computed as the distance between source points transformed by the math transform computed by thisMathTransformBuilder
, and the target points. UseStatistics.rms()
for the Root Mean Squared error.- Throws:
FactoryException
- If the math transform can't be created or used.
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computeMathTransform
Calculates the math transform immediately.- Returns:
- Math transform from
MappedPosition
. - Throws:
FactoryException
- if the math transform can't be created.
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getMathTransform
Returns the calculated math transform. This method the math transform the first time it is requested.- Returns:
- Math transform from
MappedPosition
. - Throws:
FactoryException
- if the math transform can't be created.
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getTransformation
Returns the coordinate operation wrapping the calculated math transform. The positional accuracy will be set to the Root Mean Square (RMS) of the differences between the source points transformed to the target CRS, and the expected target points.- Throws:
FactoryException
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toString
Returns a string representation of this builder. The default implementation returns a table containing all source and target points.
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