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ObjectAbstractFactory
ReferencingFactory
DefaultMathTransformFactory
public class DefaultMathTransformFactory
Low level factory for creating math transforms.
Many high level GIS applications will never need to use this factory directly;
they can use a coordinate operation factory
instead. However, the MathTransformFactory
interface can be used directly
by applications that wish to transform other types of coordinates (e.g. color coordinates,
or image pixel coordinates).
A math transform is an object that actually does
the work of applying formulae to coordinate values. The math transform does
not know or care how the coordinates relate to positions in the real world.
This lack of semantics makes implementing MathTransformFactory
significantly easier than it would be otherwise.
For example the affine transform applies a matrix to the coordinates
without knowing how what it is doing relates to the real world. So if
the matrix scales Z values by a factor of 1000, then it could
be converting meters into millimeters, or it could be converting kilometers
into meters.
Because math transforms have low semantic value
(but high mathematical value), programmers who do not have much knowledge
of how GIS applications use coordinate systems, or how those coordinate
systems relate to the real world can implement MathTransformFactory
.
The low semantic content of math transforms also
means that they will be useful in applications that have nothing to do with
GIS coordinates. For example, a math transform could be used to map color
coordinates between different color spaces, such as converting (red, green, blue)
colors into (hue, light, saturation) colors.
Since a math transform does not know what its source and target coordinate systems mean, it is not necessary or desirable for a math transform object to keep information on its source and target coordinate systems.
modules/library/referencing (gt-referencing.jar)
Field Summary |
---|
Fields inherited from class ReferencingFactory |
---|
LOGGER |
Fields inherited from class AbstractFactory |
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hints, MAXIMUM_PRIORITY, MINIMUM_PRIORITY, NORMAL_PRIORITY, priority |
Constructor Summary | |
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DefaultMathTransformFactory()
Constructs a default math transform factory. |
Method Summary | |
---|---|
MathTransform |
createAffineTransform(Matrix matrix)
Creates an affine transform from a matrix. |
MathTransform |
createBaseToDerived(CoordinateReferenceSystem baseCRS,
MathTransform projection,
CoordinateSystem derivedCS)
Creates a transform from a base CRS to a derived CS. |
MathTransform |
createBaseToDerived(CoordinateReferenceSystem baseCRS,
ParameterValueGroup parameters,
CoordinateSystem derivedCS)
Creates a parameterized transform from a base CRS to a derived CS. |
MathTransform |
createConcatenatedTransform(MathTransform transform1,
MathTransform transform2)
Creates a transform by concatenating two existing transforms. |
MathTransform |
createFromWKT(String text)
Creates a math transform object from a Well Known Text (WKT). |
MathTransform |
createFromXML(String xml)
Creates a math transform object from a XML string. |
MathTransform |
createParameterizedTransform(ParameterValueGroup parameters)
Creates a transform from a group of parameters. |
MathTransform |
createPassThroughTransform(int firstAffectedOrdinate,
MathTransform subTransform,
int numTrailingOrdinates)
Creates a transform which passes through a subset of ordinates to another transform. |
Set<OperationMethod> |
getAvailableMethods(Class<? extends Operation> type)
Returns a set of available methods for math transforms. |
ParameterValueGroup |
getDefaultParameters(String method)
Returns the default parameter values for a math transform using the given method. |
OperationMethod |
getLastMethodUsed()
Returns the operation method used for the latest call to createParameterizedTransform
in the currently running thread. |
OperationMethod |
getOperationMethod(String name)
Returns the operation method for the specified name. |
Citation |
getVendor()
Returns the vendor responsible for creating this factory implementation. |
static void |
main(String[] args)
Dump to the standard output stream a list of available operation methods. |
void |
scanForPlugins()
Scans for factory plug-ins on the application class path. |
Methods inherited from class ReferencingFactory |
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ensureNonNull |
Methods inherited from class AbstractFactory |
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addImplementationHints, equals, getImplementationHints, getPriority, hashCode, onDeregistration, onRegistration, toString |
Methods inherited from class Object |
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clone, finalize, getClass, notify, notifyAll, wait, wait, wait |
Constructor Detail |
---|
public DefaultMathTransformFactory()
math transform
factory.
Method Detail |
---|
public Citation getVendor()
getVendor
in class ReferencingFactory
public Set<OperationMethod> getAvailableMethods(Class<? extends Operation> type)
getDefaultParameters(java.lang.String)
method in this factory.
The set of available methods is implementation dependent.
getAvailableMethods
in interface MathTransformFactory
type
- Operation.class
for fetching all operation methods,
or Projection.class
for fetching only map projection
methods.
getDefaultParameters(java.lang.String)
,
createParameterizedTransform(org.opengis.parameter.ParameterValueGroup)
public OperationMethod getLastMethodUsed()
createParameterizedTransform
in the currently running thread. Returns null
if not applicable.
getLastMethodUsed
in interface MathTransformFactory
createParameterizedTransform(org.opengis.parameter.ParameterValueGroup)
public OperationMethod getOperationMethod(String name) throws NoSuchIdentifierException
name
- The case insensitive
identifier code
of the operation method to search for (e.g. "Transverse_Mercator"
).
NoSuchIdentifierException
- if there is no operation method registered for the
specified name.public ParameterValueGroup getDefaultParameters(String method) throws NoSuchIdentifierException
getAvailableMethods(java.lang.Class extends org.opengis.referencing.operation.Operation>)
method. A typical example is
"Transverse_Mercator"
).
This method creates new parameter instances at every call. It is intented to be modified
by the user before to be passed to createParameterizedTransform(parameters)
.
getDefaultParameters
in interface MathTransformFactory
method
- The case insensitive name of the method to search for.
NoSuchIdentifierException
- if there is no transform registered for the specified
method.getAvailableMethods(java.lang.Class extends org.opengis.referencing.operation.Operation>)
,
createParameterizedTransform(org.opengis.parameter.ParameterValueGroup)
,
AbstractMathTransform.getParameterValues()
public MathTransform createBaseToDerived(CoordinateReferenceSystem baseCRS, ParameterValueGroup parameters, CoordinateSystem derivedCS) throws NoSuchIdentifierException, FactoryException
"semi_major"
and "semi_minor"
parameters are
not explicitly specified, they will be inferred from the ellipsoid
and added to parameters
. In addition, this method performs axis switch as needed.
The operation method used can be obtained by a call to
#getLastUsedMethod
.
createBaseToDerived
in interface MathTransformFactory
baseCRS
- The source coordinate reference system.parameters
- The parameter values for the transform.derivedCS
- the target coordinate system.
NoSuchIdentifierException
- if there is no transform registered for the method.
FactoryException
- if the object creation failed. This exception is thrown
if some required parameter has not been supplied, or has illegal value.public MathTransform createBaseToDerived(CoordinateReferenceSystem baseCRS, MathTransform projection, CoordinateSystem derivedCS) throws FactoryException
baseCRS
- The source coordinate reference system.projection
- The "raw" base to derived transform.derivedCS
- the target coordinate system.
FactoryException
- if the object creation failed. This exception is thrown
if some required parameter has not been supplied, or has illegal value.public MathTransform createParameterizedTransform(ParameterValueGroup parameters) throws NoSuchIdentifierException, FactoryException
ParameterValueGroup p = factory.getDefaultParameters("Transverse_Mercator"); p.parameter("semi_major").setValue(6378137.000); p.parameter("semi_minor").setValue(6356752.314); MathTransform mt = factory.createParameterizedTransform(p);
createParameterizedTransform
in interface MathTransformFactory
parameters
- The parameter values.
NoSuchIdentifierException
- if there is no transform registered for the method.
FactoryException
- if the object creation failed. This exception is thrown
if some required parameter has not been supplied, or has illegal value.getDefaultParameters(java.lang.String)
,
getAvailableMethods(java.lang.Class extends org.opengis.referencing.operation.Operation>)
,
#getLastUsedMethod
public MathTransform createAffineTransform(Matrix matrix) throws FactoryException
M
, and output dimension
is N
, then the matrix will have size [N+1][M+1]
.
The +1 in the matrix dimensions allows the matrix to do a shift, as well as
a rotation. The [M][j]
element of the matrix will be the j'th
ordinate of the moved origin. The [i][N]
element of the matrix
will be 0 for i less than M
, and 1 for i
equals M
.
createAffineTransform
in interface MathTransformFactory
matrix
- The matrix used to define the affine transform.
FactoryException
- if the object creation failed.public MathTransform createConcatenatedTransform(MathTransform transform1, MathTransform transform2) throws FactoryException
createConcatenatedTransform
in interface MathTransformFactory
transform1
- The first transform to apply to points.transform2
- The second transform to apply to points.
FactoryException
- if the object creation failed.public MathTransform createPassThroughTransform(int firstAffectedOrdinate, MathTransform subTransform, int numTrailingOrdinates) throws FactoryException
createPassThroughTransform
in interface MathTransformFactory
firstAffectedOrdinate
- The lowest index of the affected ordinates.subTransform
- Transform to use for affected ordinates.numTrailingOrdinates
- Number of trailing ordinates to pass through.
Affected ordinates will range from firstAffectedOrdinate
inclusive to dimTarget-numTrailingOrdinates
exclusive.
Source: firstAffectedOrdinate + subTransform.getSourceDimensions() + numTrailingOrdinates Target: firstAffectedOrdinate + subTransform.getTargetDimensions() + numTrailingOrdinates
FactoryException
- if the object creation failed.public MathTransform createFromXML(String xml) throws FactoryException
createFromXML
in interface MathTransformFactory
xml
- Math transform encoded in XML format.
FactoryException
- if the object creation failed.public MathTransform createFromWKT(String text) throws FactoryException
createFromWKT
in interface MathTransformFactory
text
- Math transform encoded in Well-Known Text format.
null
).
FactoryException
- if the Well-Known Text can't be parsed,
or if the math transform creation failed from some other reason.public void scanForPlugins()
public static void main(String[] args)
java org.geotools.referencing.operation.DefaultMathTransformFactory
<options> <method>
where options are:
-projections |
List only projections |
-conversions |
List only conversions |
-all |
List the parameters for all transforms |
-encoding <code> |
Set the character encoding |
-locale <language> |
Set the language for the output (e.g. "fr" for French) |
and <method> is the optional name of an operation method
(e.g. "Affine"
, "EPSG:9624"
or just
"9624"
for the affine transform method).
Note for Windows users: If the output contains strange
symbols, try to supply an "-encoding
" argument. Example:
java org.geotools.referencing.operation.DefaultMathTransformFactory -encoding Cp850
The codepage number (850 in the previous example) can be obtained from the DOS
commande line using the "chcp
" command with no arguments.
args
- Command line arguments.
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