2 files changed, 19 insertions, 0 deletions

diff --git a/packages/base/src/Numeric/LinearAlgebra/Util.hs b/packages/base/src/Numeric/LinearAlgebra/Util.hs
index 779630f..60079e7 100644
--- a/packages/base/src/Numeric/LinearAlgebra/Util.hs
+++ b/packages/base/src/Numeric/LinearAlgebra/Util.hs
@@ -473,3 +473,17 @@ dispShort maxr maxc dec m =
   where
     fmt = printf ("%."++show dec ++"f")
 
+--------------------------------------------------------------------------------
+
+instance Testable (Matrix I) where
+   checkT _ = test
+
+test :: (Bool, IO())
+test = (and ok, print ok)
+  where
+    m  = (3><4) [1..12] :: Matrix I
+    md = fromInt m      :: Matrix Double
+    ok = [ tr m <> m == toInt (tr md <> md)
+         , m <> tr m == toInt (md <> tr md)
+         ]
+
diff --git a/packages/tests/src/Numeric/LinearAlgebra/Tests.hs b/packages/tests/src/Numeric/LinearAlgebra/Tests.hs
index 71c7c16..b138c2b 100644
--- a/packages/tests/src/Numeric/LinearAlgebra/Tests.hs
+++ b/packages/tests/src/Numeric/LinearAlgebra/Tests.hs
@@ -379,6 +379,10 @@ staticTest = utest "static" (fst $ checkT (undefined :: L 3 5))
 
 --------------------------------------------------------------------------------
 
+intTest = utest "int ops" (fst $ checkT (undefined :: Matrix I))
+
+--------------------------------------------------------------------------------
+
 indexProp g f x = a1 == g a2 && a2 == a3 && b1 == g b2 && b2 == b3
   where
     l = map g (toList (f x))
@@ -567,6 +571,7 @@ runTests n = do
         , convolutionTest
         , sparseTest
         , staticTest
+        , intTest
         ]
     when (errors c + failures c > 0) exitFailure
     return ()