2 files changed, 43 insertions, 19 deletions

diff --git a/lib/Data/Packed/Internal/Matrix.hs b/lib/Data/Packed/Internal/Matrix.hs
index 29aba51..57142b7 100644
--- a/lib/Data/Packed/Internal/Matrix.hs
+++ b/lib/Data/Packed/Internal/Matrix.hs
@@ -31,7 +31,8 @@ module Data.Packed.Internal.Matrix(
     liftMatrix, liftMatrix2,
     (@@>),
     saveMatrix,
-    singleton
+    singleton,
+    size, shSize, conformVs, conformMs, conformVTo, conformMTo
 ) where
 
 import Data.Packed.Internal.Common
@@ -441,3 +442,34 @@ saveMatrix filename fmt m = do
     free charfmt
 
 foreign import ccall "matrix_fprintf" matrix_fprintf :: Ptr CChar -> Ptr CChar -> CInt -> TM
+
+----------------------------------------------------------------------
+
+conformMs ms = map (conformMTo (r,c)) ms
+  where
+    r = maximum (map rows ms)
+    c = maximum (map cols ms)
+
+conformVs vs = map (conformVTo n) vs
+  where
+    n = maximum (map dim vs)
+
+conformMTo (r,c) m
+    | size m == (r,c) = m
+    | size m == (1,1) = reshape c (constantD (m@@>(0,0)) (r*c))
+    | size m == (r,1) = repCols c m
+    | size m == (1,c) = repRows r m
+    | otherwise = error $ "matrix " ++ shSize m ++ " cannot be expanded to (" ++ show r ++ "><"++ show c ++")"
+
+conformVTo n v
+    | dim v == n = v
+    | dim v == 1 = constantD (v@>0) n
+    | otherwise = error $ "vector of dim=" ++ show (dim v) ++ " cannot be expanded to dim=" ++ show n
+
+repRows n x = fromRows (replicate n (flatten x))
+repCols n x = fromColumns (replicate n (flatten x))
+
+size m = (rows m, cols m)
+
+shSize m = "(" ++ show (rows m) ++"><"++ show (cols m)++")"
+
diff --git a/lib/Data/Packed/Matrix.hs b/lib/Data/Packed/Matrix.hs
index aad73dd..ab68618 100644
--- a/lib/Data/Packed/Matrix.hs
+++ b/lib/Data/Packed/Matrix.hs
@@ -302,30 +302,22 @@ repmat m r c = fromBlocks $ splitEvery c $ replicate (r*c) m
 -- | A version of 'liftMatrix2' which automatically adapt matrices with a single row or column to match the dimensions of the other matrix.
 liftMatrix2Auto :: (Element t, Element a, Element b) => (Vector a -> Vector b -> Vector t) -> Matrix a -> Matrix b -> Matrix t
 liftMatrix2Auto f m1 m2
-    | compat' m1 m2 = lM f m1 m2
-
-    | r1 == 1  && c2 == 1 = lM f (repRows r2 m1) (repCols c1 m2)
-    | c1 == 1  && r2 == 1 = lM f (repCols c2 m1) (repRows r1 m2)
-    
-    | r1 == r2 && c2 == 1 = lM f m1              (repCols c1 m2)
-    | r1 == r2 && c1 == 1 = lM f (repCols c2 m1) m2
-
-    | c1 == c2 && r2 == 1 = lM f m1              (repRows r1 m2)
-    | c1 == c2 && r1 == 1 = lM f (repRows r2 m1) m2
-
-    | otherwise    = error $ "nonconformable matrices in liftMatrix2Auto: "
-                             ++ show (size m1) ++ ", " ++ show (size m2)
+    | compat' m1 m2 = lM f m1  m2
+    | ok            = lM f m1' m2'
+    | otherwise = error $ "nonconformable matrices in liftMatrix2Auto: " ++ shSize m1 ++ ", " ++ shSize m2
   where
     (r1,c1) = size m1
     (r2,c2) = size m2
-
-size m = (rows m, cols m)
+    r = max r1 r2
+    c = max c1 c2
+    r0 = min r1 r2
+    c0 = min c1 c2
+    ok = r0 == 1 || r1 == r2 && c0 == 1 || c1 == c2
+    m1' = conformMTo (r,c) m1
+    m2' = conformMTo (r,c) m2
 
 lM f m1 m2 = reshape (max (cols m1) (cols m2)) (f (flatten m1) (flatten m2))
 
-repRows n x = fromRows (replicate n (flatten x))
-repCols n x = fromColumns (replicate n (flatten x))
-
 compat' :: Matrix a -> Matrix b -> Bool
 compat' m1 m2 = s1 == (1,1) || s2 == (1,1) || s1 == s2
   where