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60 lines
2.4 KiB
Plaintext
60 lines
2.4 KiB
Plaintext
[/============================================================================
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Boost.Geometry Index
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Copyright (c) 2011-2012 Adam Wulkiewicz.
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Use, modification and distribution is subject to the Boost Software License,
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Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at
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http://www.boost.org/LICENSE_1_0.txt)
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=============================================================================/]
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[section:rtree_quickstart Quick Start]
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This Quick Start section shows a simple way to create a typical R-tree and perform
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spatial query.
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The code below assumes that following files are included and namespaces used.
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[rtree_quickstart_include]
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Typically you'll store e.g. `std::pair<Box, MyGeometryId>` in the __rtree__. `MyGeometryId`
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will be some identifier of a complex `Geometry` stored in other container, e.g. index type
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of a `Polygon` stored in the vector or an iterator of list of `Ring`s. To keep it simple to
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define `Value` we will use predefined __box__ and unsigned int.
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[rtree_quickstart_valuetype]
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R-tree may be created using various algorithm and parameters. You should choose the algorithm you'll
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find the best for your purpose. In this example we will use quadratic algorithm. Parameters are
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passed as template parameters. Maximum number of elements in nodes is set to 16.
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[rtree_quickstart_create]
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Typically `Value`s will be generated in a loop from e.g. `Polygon`s stored in some other container.
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In this case `Box` objects will probably be created with `geometry::envelope()` function.
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But to keep it simple let's just generate some boxes manually and insert them into the R-tree by
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using `insert()` method.
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[rtree_quickstart_insert]
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There are various types of spatial queries that may be performed, they can be even combined together
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in one call. For simplicity, we use the default one. The following query return values intersecting
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a box. The sequence of `Values` in the result is not specified.
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[rtree_quickstart_spatial_query]
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Other type of query is k-nearest neighbor search. It returns some number of values nearest to some point
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in space. The default knn query may be performed as follows. The sequence of `Values` in the result is not specified.
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[rtree_quickstart_nearest_query]
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At the end we'll print results.
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[rtree_quickstart_output]
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[h3 More]
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More information about the R-tree implementation, other algorithms and queries may be found in
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other parts of this documentation.
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[endsect]
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