5 files changed, 8 insertions, 18 deletions

diff --git a/packages/base/src/Internal/LAPACK.hs b/packages/base/src/Internal/LAPACK.hs
index 13340f2..f2fc68d 100644
--- a/packages/base/src/Internal/LAPACK.hs
+++ b/packages/base/src/Internal/LAPACK.hs
@@ -513,7 +513,7 @@ qrgrC :: Int -> (Matrix (Complex Double), Vector (Complex Double)) -> Matrix (Co
 qrgrC = qrgrAux zungqr "qrgrC"
 
 qrgrAux f st n (a, tau) = unsafePerformIO $ do
-    res <- copy ColumnMajor (sliceMatrix (0,0) (rows a,n) a)
+    res <- copy ColumnMajor (subMatrix (0,0) (rows a,n) a)
     f # (subVector 0 n tau') # res #| st
     return res
   where
diff --git a/packages/base/src/Internal/Matrix.hs b/packages/base/src/Internal/Matrix.hs
index df56207..5163421 100644
--- a/packages/base/src/Internal/Matrix.hs
+++ b/packages/base/src/Internal/Matrix.hs
@@ -70,7 +70,7 @@ is1d (size->(r,c)) = r==1 || c==1
 {-# INLINE is1d #-}
 
 -- data is not contiguous
-isSlice m@(size->(r,c)) = (c < xRow m || r < xCol m) && min r c > 1
+isSlice m@(size->(r,c)) = r*c < dim (xdat m)
 {-# INLINE isSlice #-}
 
 orderOf :: Matrix t -> MatrixOrder
@@ -359,26 +359,16 @@ instance Element Z where
 
 -------------------------------------------------------------------
 
+-- | reference to a rectangular slice of a matrix (no data copy)
 subMatrix :: Element a
-          => (Int,Int) -- ^ (r0,c0) starting position
-          -> (Int,Int) -- ^ (rt,ct) dimensions of submatrix
-          -> Matrix a -- ^ input matrix
-          -> Matrix a -- ^ result
-subMatrix (r0,c0) (rt,ct) m
-    | 0 <= r0 && 0 <= rt && r0+rt <= rows m &&
-      0 <= c0 && 0 <= ct && c0+ct <= cols m = unsafePerformIO $ extractR RowMajor m 0 (idxs[r0,r0+rt-1]) 0 (idxs[c0,c0+ct-1])
-    | otherwise = error $ "wrong subMatrix "++show ((r0,c0),(rt,ct))++" of "++shSize m
-
-
-sliceMatrix :: Element a
             => (Int,Int) -- ^ (r0,c0) starting position
             -> (Int,Int) -- ^ (rt,ct) dimensions of submatrix
             -> Matrix a -- ^ input matrix
             -> Matrix a -- ^ result
-sliceMatrix (r0,c0) (rt,ct) m
+subMatrix (r0,c0) (rt,ct) m
     | 0 <= r0 && 0 <= rt && r0+rt <= rows m &&
       0 <= c0 && 0 <= ct && c0+ct <= cols m = res
-    | otherwise = error $ "wrong sliceMatrix "++show ((r0,c0),(rt,ct))++" of "++shSize m
+    | otherwise = error $ "wrong subMatrix "++show ((r0,c0),(rt,ct))++" of "++shSize m
   where
     p = r0 * xRow m + c0 * xCol m
     tot | rowOrder m = ct + (rt-1) * xRow m
diff --git a/packages/base/src/Internal/ST.hs b/packages/base/src/Internal/ST.hs
index 62dfddf..544c9e4 100644
--- a/packages/base/src/Internal/ST.hs
+++ b/packages/base/src/Internal/ST.hs
@@ -231,7 +231,7 @@ extractMatrix (STMatrix m) rr rc = unsafeIOToST (extractR (orderOf m) m 0 (idxs[
 -- | r0 c0 height width
 data Slice s t = Slice (STMatrix s t) Int Int Int Int
 
-slice (Slice (STMatrix m) r0 c0 nr nc) = sliceMatrix (r0,c0) (nr,nc) m
+slice (Slice (STMatrix m) r0 c0 nr nc) = subMatrix (r0,c0) (nr,nc) m
 
 gemmm :: Element t => t -> Slice s t -> t -> Slice s t -> Slice s t -> ST s ()
 gemmm beta (slice->r) alpha (slice->a) (slice->b) = res
diff --git a/packages/base/src/Internal/Util.hs b/packages/base/src/Internal/Util.hs
index 258c3a3..4123e6c 100644
--- a/packages/base/src/Internal/Util.hs
+++ b/packages/base/src/Internal/Util.hs
@@ -849,7 +849,7 @@ viewBlock' r c m
     m12 = subm (0,c) (r,ct-c)    m
     m21 = subm (r,0) (rt-r,c)    m
     m22 = subm (r,c) (rt-r,ct-c) m
-    subm = sliceMatrix
+    subm = subMatrix
 
 viewBlock m = viewBlock' n n m
   where
diff --git a/packages/base/src/Numeric/LinearAlgebra/Devel.hs b/packages/base/src/Numeric/LinearAlgebra/Devel.hs
index f6fa92a..57a68e7 100644
--- a/packages/base/src/Numeric/LinearAlgebra/Devel.hs
+++ b/packages/base/src/Numeric/LinearAlgebra/Devel.hs
@@ -62,7 +62,7 @@ module Numeric.LinearAlgebra.Devel(
     GMatrix(..),
 
     -- * Misc
-    toByteString, fromByteString, sliceMatrix, showInternal
+    toByteString, fromByteString, showInternal
 
 ) where