Package eu.europa.ec.eurostat.jgiscotools.geodiff

Class GeoDiff

java.lang.Object

eu.europa.ec.eurostat.jgiscotools.geodiff.GeoDiff

public class GeoDiff
extends Object

Analyse the differences between two versions of a dataset. Compute the difference in GeoDiff format. Note: both datasets are suppose to have a shared stable identifier.

Author:

julien Gaffuri

Constructor Summary

Constructors

Constructor	Description
GeoDiff(Collection<Feature> fs1, Collection<Feature> fs2)
GeoDiff(Collection<Feature> fs1, Collection<Feature> fs2, double resolution)

Method Summary

Modifier and Type	Method	Description
static void	applyChange(Feature f, Feature diff, String ct)	Apply a change to a feature.
static void	applyChanges(Collection<Feature> fs, Collection<Feature> differences)	Apply changes to features.
static Feature	compare(Feature fs1, Feature fs2, double resolution, List<String> attributesToIgnore)	Compare two versions of the same feature.
static boolean	equals(Collection<Feature> fs1, Collection<Feature> fs2)	Analyse the differences between two datasets to check wether they are identical.
static boolean	equals(Collection<Feature> fs1, Collection<Feature> fs2, double resolution)	Analyse the differences between two datasets to check wether they are identical.
static Collection<Feature>	findIdStabilityIssues(Collection<Feature> differences, double resolution)	Detect among some differences the ones are are unecessary: The deletion and insertion of features with very similar geometries.
List<String>	getAttributesToIgnore()
static HashMap<String,Class<?>>	getCommonAttributes(Collection<Feature> fs1, Collection<Feature> fs2)
Collection<Feature>	getDifferences()
static Collection<Feature>	getDifferences(Collection<Feature> fs1, Collection<Feature> fs2, double resolution)	Return the differences from a version of a dataset to another one.
Collection<Feature>	getGeomDifferences()	Features representing the geometrical parts which have been deleted/inserted between the two versions.
Collection<Feature>	getHausdorffGeomDifferences()	A collection of features representing the geometrical differences.
Collection<Feature>	getIdentical()
double	getResolution()
void	setAttributesToIgnore(String... attributesToIgnore)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

GeoDiff

public GeoDiff(Collection<Feature> fs1,
               Collection<Feature> fs2,
               double resolution)

Parameters:

fs1 - The dataset in the first version.

fs2 - The dataset in the second version.

resolution - The geometrical resolution of the dataset. Geometrical differences below this value will be ignored.

GeoDiff

public GeoDiff(Collection<Feature> fs1,
               Collection<Feature> fs2)

Parameters:

fs1 - The dataset in the first version.

fs2 - The dataset in the second version.

Method Detail

getResolution

public double getResolution()

Returns:

The geometrical resolution of the dataset. Geometrical differences below this value will be ignored.

getDifferences

public Collection<Feature> getDifferences()

Returns:

The differences between the two versions.

getIdentical

public Collection<Feature> getIdentical()

Returns:

The features that have are identical.

getAttributesToIgnore

public List<String> getAttributesToIgnore()

Returns:

setAttributesToIgnore

public void setAttributesToIgnore(String... attributesToIgnore)

Parameters:

attributesToIgnore -

compare

public static Feature compare(Feature fs1,
                              Feature fs2,
                              double resolution,
                              List<String> attributesToIgnore)

Compare two versions of the same feature. Both features are expected to have the same identifier and the same structure (list of attributes). The differences can be either on the attribute values, or on the geometry.

Parameters:

fs1 - The dataset in the first version

fs2 - The dataset in the second version

attributesToIgnore -

resolution - The geometrical resolution of the dataset. Geometrical differences below this value will be ignored.

Returns:

A feature representing the difference.

getHausdorffGeomDifferences

public Collection<Feature> getHausdorffGeomDifferences()

A collection of features representing the geometrical differences. For each feature whose geometry is different, a segment representing the hausdorff distance between the first and second version geometries is created. This feature allows assessing the magnitude of the geometrical difference.

Returns:

getGeomDifferences

public Collection<Feature> getGeomDifferences()

Features representing the geometrical parts which have been deleted/inserted between the two versions.

Returns:

findIdStabilityIssues

public static Collection<Feature> findIdStabilityIssues(Collection<Feature> differences,
                                                        double resolution)

Detect among some differences the ones are are unecessary: The deletion and insertion of features with very similar geometries. This happen when id stability is not strictly followed.

Parameters:

differences - The differences to check.

resolution - The spatial resolution value to consider two geometries as similar.

Returns:

The collection of unecessary differences.

getDifferences

public static Collection<Feature> getDifferences(Collection<Feature> fs1,
                                                 Collection<Feature> fs2,
                                                 double resolution)

Return the differences from a version of a dataset to another one.

Parameters:

fs1 - The dataset first version

fs2 - The dataset second version

resolution - The geometrical resolution of the dataset. Geometrical differences below this value will be ignored.

Returns:

The differences

equals

public static boolean equals(Collection<Feature> fs1,
                             Collection<Feature> fs2,
                             double resolution)

Analyse the differences between two datasets to check wether they are identical.

Parameters:

fs1 - The first dataset

fs2 - The second dataset

resolution - The geometrical resolution of the dataset. Geometrical differences below this value will be ignored.

Returns:

equals

public static boolean equals(Collection<Feature> fs1,
                             Collection<Feature> fs2)

Analyse the differences between two datasets to check wether they are identical.

Parameters:

fs1 - The first dataset

fs2 - The second dataset

Returns:

applyChanges

public static void applyChanges(Collection<Feature> fs,
                                Collection<Feature> differences)

Apply changes to features.

Parameters:

fs - The features to change, in their initial version.

differences - The changes to apply.

applyChange

public static void applyChange(Feature f,
                               Feature diff,
                               String ct)

Apply a change to a feature.

Parameters:

f - The feature to change, in its initial version.

diff - The change. NB: this change cannot be a deletion or an insertion

ct - The type of change, if known.

getCommonAttributes

public static HashMap<String,Class<?>> getCommonAttributes(Collection<Feature> fs1,
                                                                 Collection<Feature> fs2)