Cookbook2.java

package cookbook;

import water.*;
import water.fvec.Frame;
import water.exec.Flow;
import water.util.Utils.*;
import hex.Summary2.SummaryPerRow;

// Called from FlowTest, and is NOT a JUnit - so instances of this class will
// be lazily generated, so we do not need any TypeMap ID's before the H2O is up.
public class Cookbook2 {

  // Use a static method so all my anonymous inner classes do not carry a hidden
  // link to a FlowTest object.
  public static void basicStatic( Key k, Frame fr ) {
    try {
      final int cyl_idx = fr.find("cylinders");
      final int year_idx = fr.find("year");
      //final int cyl_idx = fr.find("C54"); // Works great for finding covtype - average elevation by class
      //final int year_idx = fr.find("C0");
    
      SumCol sumcols = fr.
        with(new SumCol(year_idx)).
        doit();
      System.out.println(sumcols._sum+"/"+sumcols._n+" = "+(sumcols._sum/sumcols._n));
      System.out.println();

      SumCol sumCol = new SumCol(year_idx);
      Flow.FlowPerRow<SumCol> flowPerRow = fr.with(sumCol);
      SumCol result = flowPerRow.doit();
      System.out.println("TOM: " + result._sum + " " + result._n);
      
      SumCol sumcols1 = fr.
        with(new Flow.Filter() { public boolean filter(double ds[]) { return ds[cyl_idx]!=5; } }).
        with(new SumCol(year_idx)).
        doit();
      System.out.println(sumcols1._sum+"/"+sumcols1._n+" = "+(sumcols1._sum/sumcols1._n));
      System.out.println();

      // Run all the rollups in parallel before doing summary
      Futures fs = new Futures();
      for( int i=0; i<fr.numCols(); i++ )
        fr.vecs()[i].rollupStats(fs);
      fs.blockForPending();
      
      IcedHashMap<IcedLong,SumCol> sumcols2 = fr.
        with(new Flow.GroupBy() { public long groupId(double ds[]) { return (long)ds[cyl_idx];} }).
        with(new SumCol(year_idx)).
        doit();
      for( IcedLong gid : sumcols2.keySet() ) {
        SumCol sumcol = sumcols2.get(gid);
        System.out.println("Cyl="+gid._val+", "+sumcol._sum+"/"+sumcol._n+" = "+(sumcol._sum/sumcol._n));
      }
      System.out.println();

      {
        System.out.println("TOM ----- START");
        class MyGroupBy extends Flow.GroupBy {
          public long groupId(double ds[]) { return (long)ds[cyl_idx];}
        }

        SumCol sumCol10 = new SumCol(year_idx);
        Flow.FlowGroupBy flowGroupBy = fr.with(new MyGroupBy());
        Flow.FlowGroupPerRow flowGroupPerRow = flowGroupBy.with(sumCol10);
        IcedHashMap<IcedLong,SumCol> hashMap = flowGroupPerRow.doit();
        for( IcedLong gid : hashMap.keySet() ) {
          SumCol sumcol = sumcols2.get(gid);
          System.out.println("Cyl="+gid._val+", "+sumcol._sum+"/"+sumcol._n+" = "+(sumcol._sum/sumcol._n));
        }
        System.out.println("TOM ----- END");
        System.out.println();
      }

      IcedHashMap<IcedLong,SumCol> sumcols3 = fr.
        with(new Flow.Filter () { public boolean filter(double ds[]) { return ds[cyl_idx]!=5; } }).
        with(new Flow.GroupBy() { public long groupId ( double ds[]) { return (long)ds[cyl_idx];} }).
        with(new SumCol(year_idx)).
        doit();
      for( IcedLong gid : sumcols3.keySet() ) {
        SumCol sumcol = sumcols3.get(gid);
        System.out.println("Cyl="+gid._val+", "+sumcol._sum+"/"+sumcol._n+" = "+(sumcol._sum/sumcol._n));
      }
      System.out.println();
      
      IcedHashMap<IcedLong,SumCol> sumcols4 = fr.
        with(new Flow.GroupBy() { public long groupId(double ds[]) { return (long)ds[cyl_idx];} }).
        with(new Flow.Filter() { public boolean filter(double ds[]) { return ds[cyl_idx]!=5; } }).
        with(new SumCol(year_idx)).
        doit();
      for( IcedLong gid : sumcols4.keySet() ) {
        SumCol sumcol = sumcols4.get(gid);
        System.out.println("Cyl="+gid._val+", "+sumcol._sum+"/"+sumcol._n+" = "+(sumcol._sum/sumcol._n));
      }
      System.out.println();

      // Percentiles
      SummaryPerRow spr = fr.
        with(new SummaryPerRow(fr)).
        doit();
      spr.finishUp();
      System.out.println(spr);
      System.out.println();
      
      // Percentiles per-Group
      IcedHashMap<IcedLong,SummaryPerRow> sprs = fr.
        with(new Flow.GroupBy() { public long groupId(double ds[]) { return (long)ds[cyl_idx];} }).
        with(new SummaryPerRow(fr)).
        doit();
      for( IcedLong gid : sprs.keySet() ) {
        SummaryPerRow spr2 = sprs.get(gid);
        spr2.finishUp();
        System.out.println("Group ID="+gid._val);
        System.out.println(spr2);
        System.out.println();
      }
      System.out.println();

      
    } finally {
      UKV.remove(k);
    }
  }

  public static class SumCol extends Flow.PerRow<SumCol> {
    final int _col_idx;
    double _sum, _n;
    SumCol( int col_idx  ) { _col_idx = col_idx; }
    @Override public void mapreduce( double ds[] ) { _sum += ds[_col_idx]; _n++; }
    @Override public void reduce( SumCol that ) { _sum += that._sum; _n += that._n; }
    @Override public SumCol make() { return new SumCol(_col_idx); }
  }
}