Mahout的Canopy算法继续学习

今天canopy算法大部分内容都差不多理解了，但是还有许多疑问尤其是算法本身的过程T1的作用还是不是太清楚，今天主要是对通过

Path clustersOut = CanopyDriver.buildClusters(new Configuration(),  directoryContainingConvertedInput, ouput, measure, t1, t2, t1, t2, 0, false);

确定中心点后怎么对各个Vector进行分类的代码mr进行了分析，它只用了一个mapper

protected void setup(Mapper<WritableComparable<?>, VectorWritable, IntWritable, WeightedVectorWritable>.Context context) throws IOException, InterruptedException {
    super.setup(context);
    Configuration conf = context.getConfiguration();
    String clustersIn = conf.get("clusters_in");
    this.threshold = (double)conf.getFloat("pdf_threshold", 0.0F);
    this.emitMostLikely = conf.getBoolean("emit_most_likely", false);
    this.clusterModels = new ArrayList();//获得族中心点
    if (clustersIn != null && !clustersIn.isEmpty()) {
        Path clustersInPath = new Path(clustersIn);
        this.clusterModels = populateClusterModels(clustersInPath, conf);
        ClusteringPolicy policy = ClusterClassifier.readPolicy(finalClustersPath(clustersInPath));//获得策略
        this.clusterClassifier = new ClusterClassifier(this.clusterModels, policy);
    }

    this.clusterId = new IntWritable();
}

下面是map

protected void map(WritableComparable<?> key, VectorWritable vw, Mapper<WritableComparable<?>, VectorWritable, IntWritable, WeightedVectorWritable>.Context context) throws IOException, InterruptedException {
    if (!this.clusterModels.isEmpty()) {
        Class<? extends Vector> vectorClass = vw.get().getClass();
        Vector vector = vw.get();
        if (!vectorClass.equals(NamedVector.class)) {
            if (key.getClass().equals(Text.class)) {
                vector = new NamedVector((Vector)vector, key.toString());
            } else if (key.getClass().equals(IntWritable.class)) {
                vector = new NamedVector((Vector)vector, Integer.toString(((IntWritable)key).get()));
            }
        }

        Vector pdfPerCluster = this.clusterClassifier.classify((Vector)vector);
        

//判断是否是该类

if (this.shouldClassify(pdfPerCluster)) { if (this.emitMostLikely) { int maxValueIndex = pdfPerCluster.maxValueIndex();

//写入到文件中

this.write(new VectorWritable((Vector)vector), context, maxValueIndex, 1.0D); } else { this.writeAllAboveThreshold(new VectorWritable((Vector)vector), context, pdfPerCluster); } } }}

InpoutDriver的map很简单就是根据空格将stir

protected void map(LongWritable key, Text values, Mapper<LongWritable, Text, Text, VectorWritable>.Context context) throws IOException, InterruptedException {
    String[] numbers = SPACE.split(values.toString());
    Collection<Double> doubles = new ArrayList();
    String[] arr$ = numbers;
    int index = numbers.length;

    for(int i$ = 0; i$ < index; ++i$) {
        String value = arr$[i$];
        if (!value.isEmpty()) {
            doubles.add(Double.valueOf(value));
        }
    }

    if (!doubles.isEmpty()) {
        try {
            Vector result = (Vector)this.constructor.newInstance(doubles.size());
            index = 0;
            Iterator i$ = doubles.iterator();

            while(i$.hasNext()) {
                Double d = (Double)i$.next();
                result.set(index++, d.doubleValue());
            }

            VectorWritable vectorWritable = new VectorWritable(result);
            context.write(new Text(String.valueOf(index)), vectorWritable);
        } catch (IllegalAccessException | InvocationTargetException | InstantiationException var10) {
            throw new IllegalStateException(var10);
        }
    }

}