https://github.com/jnidzwetzki/spatial-index-java

Spatial indexing algorithms for java
https://github.com/jnidzwetzki/spatial-index-java

index n-dimensional r-tree spatial-index

Last synced: 2 months ago
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Spatial indexing algorithms for java

• Host: GitHub
• URL: https://github.com/jnidzwetzki/spatial-index-java
• Owner: jnidzwetzki
• License: apache-2.0
• Created: 2018-03-30T10:38:27.000Z (almost 7 years ago)
• Default Branch: master
• Last Pushed: 2022-01-25T09:35:54.000Z (almost 3 years ago)
• Last Synced: 2024-10-12T10:09:57.579Z (3 months ago)
• Topics: index, n-dimensional, r-tree, spatial-index
• Language: Java
• Homepage:
• Size: 55.7 KB
• Stars: 16
• Watchers: 3
• Forks: 2
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# Spatial indexing algorithms for java (sia4j)

Implementation of spatial indexing algorithms in java. At the moment, only an [r-tree](https://en.wikipedia.org/wiki/R-tree) index is implemented by this project.



  



 



  



## Features of the R-tree implementation

* Supports rectangle geometries

* Supports n-dimensional data

* Support serializing to file

* Can be used as in-memory data structure

* R-Tree can be serialized and accessed via _memory mapped io_. This is usefull for very large datasets.

## Examples

### Building the r-tree and execute a rane query

```java

// Two entries with a two-dimensional bounding box

final SpatialIndexEntry entry1 = new SpatialIndexEntry(new Hyperrectangle(1d, 2d, 1d, 2d), "abc");

final SpatialIndexEntry entry2 = new SpatialIndexEntry(new Hyperrectangle(10d, 20d, 10d, 20d), "def");

final SpatialIndexBuilder index = new RTreeBuilder();

index.bulkInsert(Arrays.asList(entry1, entry2);

// Query data

final Hyperrectangle queryBox = new Hyperrectangle(1d, 1.5d, 1d, 1.5d);

final List extends SpatialIndexEntry> resultList = index.getEntriesForRegion(queryBox);

```

### Write the r-tree into a file and read into memory

```java

// Write and read to file

final File tempFile = File.createTempFile("rtree-", "-test");

final RandomAccessFile raf = new RandomAccessFile(tempFile, "rw");		

index.writeToFile(raf);

raf.close();

final AbstractRTreeReader indexRead = new RTreeMemoryReader();

final RandomAccessFile rafRead = new RandomAccessFile(tempFile, "r");

indexRead.readFromFile(rafRead);

rafRead.close();

```

### Write the r-tree into a file and access the file via memory mapped io

```java

// Write and read to file

final File tempFile = File.createTempFile("rtree-", "-test");

final RandomAccessFile raf = new RandomAccessFile(tempFile, "rw");		

index.writeToFile(raf);

raf.close();

final AbstractRTreeReader indexRead = new RTreeMMFReader();

final RandomAccessFile rafRead = new RandomAccessFile(tempFile, "r");

indexRead.readFromFile(rafRead);

rafRead.close();

```