diff --git a/Data/Histogram.hs b/Data/Histogram.hs
--- a/Data/Histogram.hs
+++ b/Data/Histogram.hs
@@ -61,7 +61,9 @@
   , listSlicesAlongY
     -- ** Reducing along axis
   , reduceX
+  , breduceX
   , reduceY
+  , breduceY
     -- * Lift histogram transform to 2D
   , liftX
   , liftY
@@ -183,27 +185,26 @@
 ----------------------------------------------------------------
 
 slice :: (SliceableBin bin, Unbox a)
-      => HistIndex bin          -- ^ Lower inclusive bound
-      -> HistIndex bin          -- ^ Upper inclusive bound
-      -> Histogram bin a      -- ^ Histogram to slice
+      => HistIndex bin
+      -> HistIndex bin
       -> Histogram bin a
+      -> Histogram bin a
 slice = H.slice
 
 rebin :: (MergeableBin bin, Unbox a)
       => CutDirection
       -> Int      
-      -> (a -> a -> a)          -- ^ Accumulation function
+      -> (a -> a -> a)
       -> Histogram bin a
       -> Histogram bin a
 rebin = H.rebin
 -- {-# INLINE rebin #-}
 
--- | Rebin histogram
 rebinFold :: (MergeableBin bin, Unbox a, Unbox b)
           => CutDirection
           -> Int      
-          -> (b -> a -> b)          -- ^ Accumulation function
-          -> b                      -- ^ Initial value
+          -> (b -> a -> b)
+          -> b
           -> Histogram bin a
           -> Histogram bin b
 rebinFold = H.rebinFold
@@ -216,14 +217,14 @@
 ----------------------------------------------------------------
 
 sliceAlongX :: (Unbox a, Bin bX, Bin bY)
-            => Histogram (Bin2D bX bY) a -- ^ 2D histogram
-            -> HistIndex bY                -- ^ Position along Y axis
+            => Histogram (Bin2D bX bY) a
+            -> HistIndex bY
             -> Histogram bX a
 sliceAlongX = H.sliceAlongX
 
 sliceAlongY :: (Unbox a, Bin bX, Bin bY)
-            => Histogram (Bin2D bX bY) a -- ^ 2D histogram
-            -> HistIndex bX                -- ^ Position along X axis
+            => Histogram (Bin2D bX bY) a
+            -> HistIndex bX
             -> Histogram bY a
 sliceAlongY = H.sliceAlongY
 
@@ -238,16 +239,28 @@
 listSlicesAlongY = H.listSlicesAlongY
 
 reduceX :: (Unbox a, Unbox b, Bin bX, Bin bY)
-        => (Histogram bX a -> b)      -- ^ Function to reduce single slice along X axis
-        ->  Histogram (Bin2D bX bY) a -- ^ 2D histogram
+        => (Histogram bX a -> b)
+        ->  Histogram (Bin2D bX bY) a
         ->  Histogram bY b
 reduceX = H.reduceX
 
+breduceX :: (Unbox a, Unbox b, Bin bX, Bin bY)
+         => (BinValue bY -> Histogram bX a -> b)
+         ->  Histogram (Bin2D bX bY) a
+         ->  Histogram bY b
+breduceX = H.breduceX
+
 reduceY :: (Unbox a, Unbox b, Bin bX, Bin bY)
-        => (Histogram bY a -> b)     -- ^ Function to reduce histogram along Y axis
-        -> Histogram (Bin2D bX bY) a -- ^ 2D histogram
+        => (Histogram bY a -> b)
+        -> Histogram (Bin2D bX bY) a
         -> Histogram bX b
 reduceY = H.reduceY
+
+breduceY :: (Unbox a, Unbox b, Bin bX, Bin bY)
+         => (BinValue bX -> Histogram bY a -> b)
+         -> Histogram (Bin2D bX bY) a
+         -> Histogram bX b
+breduceY = H.breduceY
 
 liftX :: (Bin bX, Bin bY, Bin bX', BinEq bX', Unbox a, Unbox b)
       => (Histogram bX a -> Histogram bX' b)
diff --git a/Data/Histogram/Generic.hs b/Data/Histogram/Generic.hs
--- a/Data/Histogram/Generic.hs
+++ b/Data/Histogram/Generic.hs
@@ -61,7 +61,9 @@
   , listSlicesAlongY
     -- ** Reducing along axis
   , reduceX
+  , breduceX
   , reduceY
+  , breduceY
     -- * Lift histogram transform to 2D
   , liftX
   , liftY
@@ -483,7 +485,15 @@
 reduceX f h@(Histogram (Bin2D _ bY) _ _) =
   Histogram bY Nothing $ G.generate (nBins bY) (f . sliceAlongX h . Index)
 
+-- | Reduce along X axis. Information about under/overlows is lost.
+breduceX :: (Vector v a, Vector v b, Bin bX, Bin bY)
+         => (BinValue bY -> Histogram v bX a -> b) -- ^ Function to reduce single slice along X axis
+         ->  Histogram v (Bin2D bX bY) a           -- ^ 2D histogram
+         ->  Histogram v bY b
+breduceX f h@(Histogram (Bin2D _ bY) _ _) =
+  Histogram bY Nothing $ G.generate (nBins bY) $ \i -> f (fromIndex bY i) $ sliceAlongX h (Index i)
 
+
 -- | Reduce along Y axis. Information about under/overflows is lost.
 reduceY :: (Vector v a, Vector v b, Bin bX, Bin bY)
         => (Histogram v bY a -> b)     -- ^ Function to reduce histogram along Y axis
@@ -491,6 +501,15 @@
         -> Histogram v bX b
 reduceY f h@(Histogram (Bin2D bX _) _ _) =
   Histogram bX Nothing $ G.generate (nBins bX) (f . sliceAlongY h . Index)
+
+-- | Reduce along Y axis. Information about under/overflows is lost.
+breduceY :: (Vector v a, Vector v b, Bin bX, Bin bY)
+         => (BinValue bX -> Histogram v bY a -> b) -- ^ Function to reduce histogram along Y axis
+         -> Histogram v (Bin2D bX bY) a -- ^ 2D histogram
+         -> Histogram v bX b
+breduceY f h@(Histogram (Bin2D bX _) _ _) =
+  Histogram bX Nothing $ G.generate (nBins bX) $ \i -> f (fromIndex bX i) $ sliceAlongY h (Index i)
+
 
 -- | Transform X slices of histogram.
 liftX :: (Bin bX, Bin bY, Bin bX', BinEq bX', Vector v a, Vector v b)
diff --git a/histogram-fill.cabal b/histogram-fill.cabal
--- a/histogram-fill.cabal
+++ b/histogram-fill.cabal
@@ -1,9 +1,13 @@
 Name:           histogram-fill
-Version:        0.7.0.0
+Version:        0.7.1.0
 Synopsis:       Library for histograms creation.
 Description:    
   This is library for histograms filling. Its aim to provide
   convenient way to create and fill histograms. 
+  .
+  Changes in 0.7.1.0
+  .
+  * breduceX and breduceY are added.
   .
   Changes in 0.7.0.0
   .