r-tree - ELKI DBSCAN R* 树索引

Question

在MiniGUI中，我可以看到db.index。如何通过 Java 代码将其设置为 tree.spatial.rstarvariants.rstar.RStartTreeFactory？

我已经实现了:

params.addParameter(AbstractDatabase.Parameterizer.INDEX_ID,tree.spatial.rstarvariants.rstar.RStarTreeFactory);

对于addParameter()函数的第二个参数tree.spatial...RStarTreeFactory类未找到

// Setup parameters:
            ListParameterization params = new ListParameterization();
            params.addParameter(
                    FileBasedDatabaseConnection.Parameterizer.INPUT_ID,
                    fileLocation);
            params.addParameter(AbstractDatabase.Parameterizer.INDEX_ID,
                RStarTreeFactory.class);

我收到NullPointerException。我是否正确使用了RStarTreeFactory.class？

Answer 1

ELKI 命令行(和 MiniGui；它是一个命令行构建器)允许指定简写类名，省略已实现接口(interface)的包前缀。

完整的命令行文档产生:

-db.index <object_1|class_1,...,object_n|class_n>
    Database indexes to add.
    Implementing de.lmu.ifi.dbs.elki.index.IndexFactory
    Known classes (default package de.lmu.ifi.dbs.elki.index.):
    -> tree.spatial.rstarvariants.rstar.RStarTreeFactory
    -> ...

即对于此参数，类前缀 de.lmu.ifi.dbs.elki.index. 可以省略。

完整的类名是:

de.lmu.ifi.dbs.elki.index.tree.spatial.rstarvariants.rstar.RStarTreeFactory

或者您只需输入RStarTreeFactory，然后让 Eclipse 自动修复导入:

params.addParameter(AbstractDatabase.Parameterizer.INDEX_ID,
    RStarTreeFactory.class);
// Bulk loading static data yields much better trees and is much faster, too.
params.addParameter(RStarTreeFactory.Parameterizer.BULK_SPLIT_ID, 
    SortTileRecursiveBulkSplit.class);
// Page size should fit your dimensionality.
// For 2-dimensional data, use page sizes less than 1000.
// Rule of thumb: 15...20 * (dim * 8 + 4) is usually reasonable
// (for in-memory bulk-loaded trees)
params.addParameter(AbstractPageFileFactory.Parameterizer.PAGE_SIZE_ID, 300);

另请参阅:Geo Indexing example in the tutorial folder .