fix a small error in answer case

py/testdir_single_jvm/binquant.py

@@ -6,6 +6,7 @@
 import math
 OTHER_T = 0.5
 BIN_COUNT = 20
+BIN_COUNT = 1
 
 # Defintion (this defn. seems odd. for the case of real quantiles, it should be a  floor, not a round up?)
 # This definition may be correct for 1-based indexing. (we do zero-based indexing in the code below, so it looks different)
@@ -190,10 +191,10 @@ def htot2():
         guess = (hcnt2_max[k] - hcnt2_min[k]) / 2
 
         if currentCnt==targetCntInt:
-            if hcnt2[k]>2:
+            if hcnt2[k]>2 and (hcnt2_min[k]==hcnt2_max[k]):
                 guess = hcnt2_min[k]
                 done = True
-                print "Guess A", guess
+                print "Guess A", guess, k, hcnt2[k]
 
             if hcnt2[k]==2:
                 # no mattter what size the fraction it would be on this number

py/testdir_single_jvm/test_summary2_unifiles2.py

@@ -10,6 +10,7 @@
 
 DO_MEDIAN = True
 MAX_QBINS = 1000
+MAX_QBINS = 2
 
 def twoDecimals(l):
     if isinstance(l, list):
@@ -82,9 +83,14 @@ def generate_scipy_comparison(csvPathname, col=0, h2oMedian=None, h2oMedian2=Non
     b = h2o_summ.percentileOnSortedList(targetFP, 0.50 if DO_MEDIAN else 0.999)
     label = '50%' if DO_MEDIAN else '99.9%'
     h2p.blue_print(label, "from sort:", b)
-    h2p.blue_print(label, "from scipy:", a[5 if DO_MEDIAN else 10])
+    s = a[5 if DO_MEDIAN else 10]
+    h2p.blue_print(label, "from scipy:", s)
     h2p.blue_print(label, "from h2o singlepass:", h2oMedian)
     h2p.blue_print(label, "from h2o multipass:", h2oMedian2)
+    # they should be identical. keep a tight absolute tolerance
+    h2o_util.assertApproxEqual(h2oMedian2, b, tol=0.0000002, msg='h2o quantile multipass is not approx. same as sort algo')
+    h2o_util.assertApproxEqual(h2oMedian2, s, tol=0.0000002, msg='h2o quantile multipass is not approx. same as scipy algo')
+
     # see if scipy changes. nope. it doesn't
     if 1==0:
         a = stats.mstats.mquantiles(targetFP, prob=per)

src/main/java/hex/Quantiles.java

@@ -404,7 +404,7 @@ private boolean exactQuantilesMultiPass(double[] qtiles, double[] thres, long de
     boolean interpolated = false;
 
     if ( currentCnt==targetCntInt ) {
-      if ( hcnt2[k]>2 ) {
+      if ( hcnt2[k]>2 && (hcnt2_min[k]==hcnt2_max[k]) ) {
         guess = hcnt2_min[k];
         done = true;
         Log.info("Q_ Guess A "+guess);