Mahout Source Code Analysis of Distributedlanczossolver (v)

Mahout version: 0.7,hadoop version: 1.0.4,jdk:1.7.0_25 64bit.

1. Job Posts

Next, analyze the Run method of Eigenverificationjob:

public int Run (path corpusinput, path eigeninput, path output, P Ath Tempout, double maxerror, Double Mineigenvalue, Boolean Inmem  
    Ory, Configuration conf) throws IOException {this.outpath = output;  
    This.tmpout = Tempout;  
    This.maxerror = Maxerror;  
      
    This.mineigenvalue = Mineigenvalue;  
    if (eigeninput!= null && eigenstoverify = null) {prepareeigens (conf, eigeninput, inmemory);  
    } Distributedrowmatrix C = new Distributedrowmatrix (Corpusinput, Tempout, 1, 1);  
    c.setconf (conf);  
      
    corpus = C; Set up Eigenverifier and Orthoverifier todo:allow multithreaded execution eigenverifier = new Simpleeigen  
      
    Verifier ();  
    We don ' t currently verify orthonormality here.  
      
  Vectoriterable pairwiseinnerproducts = Computepairwiseinnerproducts ();  Map<matrixslice, eigenstatus> eigenmetadata = Verifyeigens ();  
      
    List<map.entry<matrixslice, eigenstatus>> Prunedeigenmeta = Pruneeigens (EigenMetaData);  
    Savecleaneigens (New Configuration (), Prunedeigenmeta);  
  return 0; }

Here first clear a few input parameters, InputPath, OutputPath, TempPath do not have to say, Eigenpath is the last generated raweigenvectors file; InMemory is false, Maxerror is the 0.05,mineigenvalue is 0.0; by the way, if you run this class directly, it's not going to work, like the following call:

Package MAHOUT.FANSY.SVD;  
      
Import java.io.IOException;  
Import org.apache.hadoop.conf.Configuration;  
Import Org.apache.hadoop.fs.Path;  
      
Import Org.apache.mahout.math.hadoop.decomposer.EigenVerificationJob; public class Runeigenverificationjob {/** * Call Eigenverificationjob * * private static Path P  
    Refix=new Path ("hdfs://ubuntu:9000");  
        public static void Main (string[] args) throws IOException {path inputpath=new path (prefix, "/svd/input/wine");  
        Path raweigenvectorpath=new path (prefix, "/svd/output1/raweigenvectors");  
        Path outputpath=new path (prefix, "/svd/output1/cleaneigenvectors");  
        Path outputtmppath=new path (prefix, "/svd/temp");  
              
        Double maxerror=0.5;  
        Double mineigenvalue=0.0;  
        Boolean inmemory=false;  
        Configuration conf=new Configuration ();  
        Conf.set ("Mapred.job.tracker", "ubuntu:9001"); int Result=new EigenverifiCationjob (). Run (InputPath, Raweigenvectorpath, OutputPath, outputtmp  
        Path, Maxerror, Mineigenvalue, inmemory, conf); SYSTEM.OUT.PRINTLN ("result success?")  
    + (Result==0?true:false)); }  
      
}