Package org.apache.sis.index.tree
Class PointTree<E>
Object
AbstractCollection<E>
AbstractSet<E>
PointTree<E>
- Type Parameters:
- E- the type of elements stored in this tree.
- All Implemented Interfaces:
- Serializable,- Iterable<E>,- Collection<E>,- Set<E>,- CheckedContainer<E>
A k-dimensional tree index for points.
 For k=2, this is a point QuadTree.
 For k=3, this is a point Octree.
 Higher dimensions are also accepted up to 6 dimensions.
 Elements are stored in this 
PointTree as arbitrary non-null objects with their coordinates
 computed by a user-specified locator function. That function expects an element E
 in argument and returns its coordinates as a double[] array.
 The coordinates of each elements must be stable, i.e. applying the locator function
 twice on the same element must return the same coordinates.
 Searches based on element coordinates can be done with the following methods:
 
 The performances of this PointTree depends on two parameters: an estimated bounding box of the points
 to be added in this tree and a maximal capacity of leaf nodes (not to be confused with a capacity of the tree).
 More details are given in the constructor.
 Thread-safety
This class is not thread-safe when the tree content is modified. But if the tree is kept unmodified after construction, then multiple read operations in concurrent threads are safe. Users can synchronize withReadWriteLock (the read lock must be held for complete duration
 of iterations or stream consumptions).
 Serialization
This tree is serializable if thelocator function and all elements in the tree are also serializable.
 However, the serialization details is implementation specific and may change in any future Apache SIS version.
 Limitations
Current implementation does not yet support removal of elements.References
Insertion algorithm is based on design of QuadTree index in H. Samet, The Design and Analysis of Spatial Data Structures. Massachusetts: Addison Wesley Publishing Company, 1989.- Since:
- 1.1
- See Also:
Defined in the sis-feature module
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Nested Class SummaryNested ClassesModifier and TypeClassDescriptionstatic interfaceProvides the coordinates of any element stored inPointTree.
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Field SummaryFieldsModifier and TypeFieldDescriptionstatic final intThe maximum number of dimensions (inclusive) that this class currently supports.
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Constructor SummaryConstructorsConstructorDescriptionPointTree(Class<E> elementType, Envelope bounds, PointTree.Locator<? super E> locator, int nodeCapacity, boolean parallel) Creates an initially empty k-dimensional tree with the given capacity for each node.PointTree(PointTree<E> other) Creates a new tree initialized to a copy of the given tree.
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Method SummaryModifier and TypeMethodDescriptionbooleanInserts the specified element into this tree if it is not already present.booleanaddAll(Collection<? extends E> elements) Inserts all elements from the specified collection into this tree if they are not already present.voidclear()Removes all elements from this tree.booleanReturnstrueif this set contains the specified element.Returns the coordinate reference system (CRS) of all points in this tree.final intReturns the number of dimensions of points in this tree.Returns the base type of all elements in this tree.booleanisEmpty()Returns true if this set contains no elements.iterator()Creates an iterator over all elements in this set.Returns a possibly parallel stream with this tree as its source.queryByBoundingBox(Envelope searchRegion) Returns all elements in the given bounding box.intsize()Returns the number of elements in this tree.Creates an iterator over all elements in this set.Methods inherited from class AbstractSetequals, hashCode, removeAllMethods inherited from class AbstractCollectioncontainsAll, remove, retainAll, toArray, toArray, toStringMethods inherited from class Objectclone, finalize, getClass, notify, notifyAll, wait, wait, waitMethods inherited from interface CollectionremoveIf, stream, toArrayMethods inherited from interface SetcontainsAll, remove, retainAll, toArray, toArray
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Field Details- 
MAXIMUM_DIMENSIONSpublic static final int MAXIMUM_DIMENSIONSThe maximum number of dimensions (inclusive) that this class currently supports. Current maximum is 6. This restriction come from 2⁶ = 64.- See Also:
 
 
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Constructor Details- 
PointTreeCreates a new tree initialized to a copy of the given tree. This copy constructor shares some data structure from theothertree for reducing memory usage, but the two trees are nevertheless independent (changes in a tree does not affect the other tree).- Parameters:
- other- the other tree to copy.
 
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PointTreepublic PointTree(Class<E> elementType, Envelope bounds, PointTree.Locator<? super E> locator, int nodeCapacity, boolean parallel) Creates an initially empty k-dimensional tree with the given capacity for each node. The number of dimensions of the given envelope determines the number of dimensions of points in this tree. The positions computed bylocatormust have the same number of dimensions than the given envelope.The boundsargument specifies the expected region of points to be added in thisPointTree. Those bounds do not need to be exact;PointTreewill work even if some points are located outside those bounds. However, performances will be better if the envelope center is close to the median of the points to be inserted in thePointTree, and if the majority of points are inside those bounds.The given nodeCapacityis a threshold value controlling when the content of a node should be splited into smaller children nodes. That capacity should be a relatively small number, for example 10. Determining the most efficient value may require benchmarking.- Parameters:
- elementType- the base type of all elements in this tree.
- bounds- bounds of the region of data to be inserted in the k-dimensional tree.
- locator- function computing the position of any element in this tree.
- nodeCapacity- the capacity of each node (not to be confused with a capacity of the tree).
- parallel- whether the stream can be parallel by default. Should be- falseif the given- locatoris not thread-safe.
 
 
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Method Details- 
getCoordinateReferenceSystemReturns the coordinate reference system (CRS) of all points in this tree. The CRS is taken from the envelope given in argument to the constructor.- Returns:
- the CRS of all points in this tree, if presents.
- See Also:
 
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getDimensionpublic final int getDimension()Returns the number of dimensions of points in this tree.- Returns:
- the number of dimensions of points in this tree.
- See Also:
 
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getElementTypeReturns the base type of all elements in this tree.- Specified by:
- getElementTypein interface- CheckedContainer<E>
- Returns:
- the element type.
 
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clearpublic void clear()Removes all elements from this tree.- Specified by:
- clearin interface- Collection<E>
- Specified by:
- clearin interface- Set<E>
- Overrides:
- clearin class- AbstractCollection<E>
 
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isEmptypublic boolean isEmpty()Returns true if this set contains no elements.- Specified by:
- isEmptyin interface- Collection<E>
- Specified by:
- isEmptyin interface- Set<E>
- Overrides:
- isEmptyin class- AbstractCollection<E>
- Returns:
- whether this set is empty.
 
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sizepublic int size()Returns the number of elements in this tree.- Specified by:
- sizein interface- Collection<E>
- Specified by:
- sizein interface- Set<E>
- Specified by:
- sizein class- AbstractCollection<E>
- Returns:
- the number of elements in this tree, or Integer.MAX_VALUEif there is more elements than what anintcan represent.
 
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addInserts the specified element into this tree if it is not already present.- Specified by:
- addin interface- Collection<E>
- Specified by:
- addin interface- Set<E>
- Overrides:
- addin class- AbstractCollection<E>
- Parameters:
- element- the element to insert.
- Returns:
- trueif the element has been added, or- falseif it was already present.
- Throws:
- NullPointerException- if the given element is null.
 
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addAllInserts all elements from the specified collection into this tree if they are not already present.- Specified by:
- addAllin interface- Collection<E>
- Specified by:
- addAllin interface- Set<E>
- Overrides:
- addAllin class- AbstractCollection<E>
- Parameters:
- elements- the elements to insert.
- Returns:
- trueif at least one element has been added.
- Throws:
- NullPointerException- if an element is null.
 
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containsReturnstrueif this set contains the specified element.- Specified by:
- containsin interface- Collection<E>
- Specified by:
- containsin interface- Set<E>
- Overrides:
- containsin class- AbstractCollection<E>
- Parameters:
- element- the object to search.
- Returns:
- whether this set contains the specified element.
 
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iteratorCreates an iterator over all elements in this set. In current implementation, the iterator does not support element removal.
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spliteratorCreates an iterator over all elements in this set. The iterator characteristics are sized, distinct andnon-null.- Specified by:
- spliteratorin interface- Collection<E>
- Specified by:
- spliteratorin interface- Iterable<E>
- Specified by:
- spliteratorin interface- Set<E>
 
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parallelStreamReturns a possibly parallel stream with this tree as its source. It is allowable for this method to return a sequential stream.- Specified by:
- parallelStreamin interface- Collection<E>
- Returns:
- a possibly parallel stream over the elements in this tree.
 
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queryByBoundingBoxReturns all elements in the given bounding box. The given envelope shall be in the same CRS than the points in this tree (this is currently not verified). The returned stream may be parallel by default, depending on the argument given to the constructor. If the action to be applied on the stream cannot be parallel, then user should invokeBaseStream.sequential()explicitly.- Parameters:
- searchRegion- envelope representing the rectangular search region.
- Returns:
- elements that are in the given search region (bounds inclusive).
 
 
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