fix Matrix.sumColumns output type

fix Matrix unit tests #150

src/FSharp.Stats/Matrix.fs

@@ -34,8 +34,8 @@ module Matrix =
             o.Inverse
 
     type DataSource = 
-    |Sample
-    |Population
+        |Sample
+        |Population
 
     module Generic = 
 
@@ -567,15 +567,15 @@ module Matrix =
         getDiag a
         |> diag
 
-    /// Computes the row wise sum of a Matrix
+    /// Computes the row wise sums of a Matrix
     let sumRows (a:matrix) =
         a
         |> foldByRow (fun acc r -> acc + r ) (Vector.zeroCreate a.NumRows)
 
-    /// Computes the Column wise sum of a Matrix
+    /// Computes the column wise sums of a Matrix
     let sumColumns (a:matrix) =
-        a.Transpose
-        |> foldByRow (fun acc r -> acc + r ) (Vector.zeroCreate a.NumCols)
+        a
+        |> foldByCol (fun acc r -> acc + r ) (RowVector.zero a.NumCols)
 
     /// Computes the row wise mean of a Matrix
     let meanRowWise (a:matrix) =
@@ -587,14 +587,14 @@ module Matrix =
     let meanColumnWise (a:matrix) =
         a
         |> sumColumns
-        |> Vector.map (fun sum -> sum / (a.NumRows |> float))
+        |> RowVector.map (fun sum -> sum / (a.NumRows |> float))
 
     ///Computes mean in the specified orientation
     /// orientation - "RowWise" or "ColWise"
-    let mean (orientation:Orientation) (a:matrix) = 
+    let meanAsSeq (orientation:Orientation) (a:matrix) = 
         match orientation with
-        |RowWise -> meanRowWise a
-        |ColWise -> meanColumnWise a
+        | RowWise -> meanRowWise a    |> seq
+        | ColWise -> meanColumnWise a |> seq
 
     /// computes the column specific covariance matrix of a data matrix as described at:
     // http://stattrek.com/matrix-algebra/covariance-matrix.aspx

src/FSharp.Stats/Vector.fs

@@ -170,7 +170,7 @@ module Vector =
     let ofScalar value = VecDS.scalarVecDS value
     ///Builds a new vector whose elements are the results of adding the corresponding elements of the two vectors pairwise. The two input vectors must have the same lengths, otherwise ArgumentException is raised.
     let add vector1 vector2 = VecDS.addVecDS vector1 vector2
-    ///Builds a new vector whose elements are the results of substracting the corresponding elements of vector1 from vector2. The two input vectors must have the same lengths, otherwise ArgumentException is raised.
+    ///Builds a new vector whose elements are the results of substracting the corresponding elements of vector2 from vector1. The two input vectors must have the same lengths, otherwise ArgumentException is raised.
     let sub vector1 vector2 = VecDS.subVecDS vector1 vector2
     let mulRVV vector1 vector2 = VecDS.mulRowVecVecDS vector1 vector2
     let mulVRV vector1 vector2 = VecDS.mulVecRowVecDS vector1 vector2

tests/FSharp.Stats.Tests/Matrix.fs

@@ -258,21 +258,21 @@ let floatImplementationDenseTests =
 
             testCase "ofRows" <| fun () ->
                 let actual =
-                    testValuesArrRows
+                    testValues2x3
                     |> Array.map rowvec
                     |> Vector.Generic.ofSeq
                     |> Matrix.ofRows
 
-                Expect.equal actual testSquareMatrixA "Matrix was not initialized correctly using Matrix.ofRows"
+                Expect.equal actual test2x3Matrix "Matrix was not initialized correctly using Matrix.ofRows"
 
             testCase "ofCols" <| fun () ->
                 let actual =
-                    testValuesArrCols
+                    testValues2x3Transposed
                     |> Array.map vector
                     |> RowVector.Generic.ofSeq
                     |> Matrix.ofCols
 
-                Expect.equal actual testSquareMatrixA "Matrix was not initialized correctly using Matrix.ofCols"      
+                Expect.equal actual test2x3Matrix "Matrix was not initialized correctly using Matrix.ofCols"      
 
             testCase "ofJaggedList" <| fun () ->