PUBDEV-1671: Fix variance computation for DRealHistogram when there's…

… only 1 count (N=1), was dividing by 0 during 1/N * 1/(N-1)
h2oai · Jul 27, 2015 · cf886a7 · cf886a7
1 parent 6ceac99
commit cf886a7
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/h2o-algos/src/main/java/hex/tree/DRealHistogram.java b/h2o-algos/src/main/java/hex/tree/DRealHistogram.java
@@ -25,7 +25,7 @@ public DRealHistogram(String name, final int nbins, int nbins_cats, byte isInt,
   }
   @Override public double var (int b) {
     double n = _bins[b];
-    if( n==0 ) return 0;
+    if( n<=1  ) return 0;
     return (_ssqs[b] - _sums[b]*_sums[b]/n)/(n-1);
   }