Example usage for org.apache.mahout.classifier.df DecisionForest nbNodes

Introduction

In this page you can find the example usage for org.apache.mahout.classifier.df DecisionForest nbNodes.

Prototype

public long nbNodes() 

Source Link

Usage

From source file:bigimp.BuildForest.java

License:Apache License

private void buildForest() throws IOException, ClassNotFoundException, InterruptedException {
    // make sure the output path does not exist
    FileSystem ofs = outputPath.getFileSystem(getConf());
    if (ofs.exists(outputPath)) {
        log.error("Output path already exists");
        return;//from  ww  w.ja  va  2s . c o  m
    }

    DecisionTreeBuilder treeBuilder = new DecisionTreeBuilder();
    if (m != null) {
        treeBuilder.setM(m);
    }
    treeBuilder.setComplemented(complemented);
    if (minSplitNum != null) {
        treeBuilder.setMinSplitNum(minSplitNum);
    }
    if (minVarianceProportion != null) {
        treeBuilder.setMinVarianceProportion(minVarianceProportion);
    }

    Builder forestBuilder;

    if (isPartial) {
        log.info("Partial Mapred implementation");
        forestBuilder = new PartialBuilder(treeBuilder, dataPath, datasetPath, seed, getConf());
    } else {
        log.info("InMem Mapred implementation");
        forestBuilder = new InMemBuilder(treeBuilder, dataPath, datasetPath, seed, getConf());
    }

    forestBuilder.setOutputDirName(outputPath.getName());

    log.info("Building the forest...");
    long time = System.currentTimeMillis();

    DecisionForest forest = forestBuilder.build(nbTrees);

    time = System.currentTimeMillis() - time;
    log.info("Build Time: {}", DFUtils.elapsedTime(time));
    log.info("Forest num Nodes: {}", forest.nbNodes());
    log.info("Forest mean num Nodes: {}", forest.meanNbNodes());
    log.info("Forest mean max Depth: {}", forest.meanMaxDepth());

    // store the decision forest in the output path
    Path forestPath = new Path(outputPath, "forest.seq");
    log.info("Storing the forest in: {}", forestPath);
    DFUtils.storeWritable(getConf(), forestPath, forest);
}

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