我试图打印一个混淆矩阵的j48分类器使用weka。我得到的结果是每个Map器的矩阵数。正在运行的Map程序数设置为2。
这个类是weka分类器输出的一个缩减器，它从Map器中得到一堆交叉验证的数据块，它的工作是将数据聚合到一个解决方案中。

public void reduce(Text key, Iterable<AggregateableEvaluation> values, Context context) throws IOException, InterruptedException {      
        int sum = 0;                    
        // loop through each of the values and "aggregate"
        // which basically means to consolidate the values
        for (AggregateableEvaluation val : values) {
            System.out.println("IN THE REDUCER!");

            // The first time through, give aggEval a value
            if (sum == 0) {
                try {
                    aggEval = val;
                }
                catch (Exception e) {
                    e.printStackTrace();
                }
            }
            else {
                // combine the values
                aggEval.aggregate(val);
            }

            try {
                // This is what is taken from the mapper to be aggregated
                //System.out.println("This is the map result");
                //System.out.println(aggEval.toMatrixString());
            }
            catch (Exception e) {
                e.printStackTrace();
            }                       

            sum += 1;
        }           
        try {
            System.out.println("This is reduce matrix");
            System.out.println(aggEval.toMatrixString());
        }
        catch (Exception e) {
            e.printStackTrace();
        }