Fix bug in unsafe division in both implementations of logDistributional2

src/Gargantext/Core/LinearAlgebra/Distributional.hs

@@ -212,7 +212,8 @@ distributionalReferenceImplementation m' = result
 logDistributional2 :: (A.Manifest r e
                       , A.Unbox e
                       , A.Source r Int
-                      , A.Shape r Ix2, Num e
+                      , A.Shape r Ix2
+                      , Num e
                       , Ord e
                       , A.Source r e
                       , Fractional e
@@ -272,7 +273,7 @@ logDistributional' n m' = result
 
     mi_divvy :: Matrix A.D e
     mi_divvy = A.zipWith (\m_val ss_val ->
-      let x  = m_val / ss_val
+      let x  = m_val `safeDiv` ss_val
           x' = x * to
       in if (x' < 1) then 0 else log x') m ss
 

src/Gargantext/Core/Methods/Matrix/Accelerate/Utils.hs

@@ -53,13 +53,14 @@ import qualified Gargantext.Prelude as P
 (./) :: ( Shape ix
         , Slice ix
         , Elt a
+        , Eq a
         , P.Num (Exp a)
         , P.Fractional (Exp a)
         )
      => Acc (Array ((ix :. Int) :. Int) a)
      -> Acc (Array ((ix :. Int) :. Int) a)
      -> Acc (Array ((ix :. Int) :. Int) a)
-(./) = zipWith (/)
+(./) = zipWith safeDivCond
 
 -- | Term by term division where divisions by 0 produce 0 rather than NaN. 
 termDivNan :: ( Elt a
@@ -70,7 +71,10 @@ termDivNan :: ( Elt a
            => Acc (Matrix a)
            -> Acc (Matrix a)
            -> Acc (Matrix a)
-termDivNan = zipWith (\i j -> cond ((==) j 0) 0 ((/) i j))
+termDivNan = zipWith safeDivCond
+
+safeDivCond :: (Eq a, P.Num (Exp a), P.Fractional (Exp a)) => Exp a -> Exp a -> Exp a
+safeDivCond i j = cond ((==) j 0) 0 ((/) i j)
 
 (.-) :: ( Shape ix
         , Slice ix

test/Test/Core/LinearAlgebra.hs

@@ -96,7 +96,30 @@ testMatrix_02 = SquareMatrix $ fromList (Z :. 7 :. 7) $
       7, -12,  12,  -2,  36,  10,  34,
      13, -37, -16,   2,   7, -13,  21]
 
+testMatrix_03 :: SquareMatrix Int
+testMatrix_03 = SquareMatrix $ fromList (Z :. 11 :. 11) $
+  [  1, -1,  1,  0,  1, -1, 0,  1,  1,  0,  0,
+     1,  1,  1,  1,  1,  0, 1, -1,  1,  0,  0,
+    -1,  1,  0, -1,  0, -1, 0,  1,  0, -1,  0,
+     1,  1,  1, -1, -1,  0, 1, -1,  0,  0, -1,
+    -1,  1, -1, -1,  0,  1, 1,  1, -1, -1, -1,
+     1,  1,  0, -1, -1, -1, 1,  0,  1, -1, -1,
+    -1,  1,  0, -1,  1, -1, 0,  1, -1, -1, -1,
+     1,  1, -1,  1,  1,  0, 1, -1,  1, -1,  1,
+    -1, -1,  0,  1,  1,  0, 1,  1, -1,  1,  0,
+     1,  1,  0, -1,  1, -1, 1,  0,  1,  0, -1,
+     1,  1, -1,  0, -1, -1, 1,  0,  1,  0, -1]
 
+testMatrix_04 :: SquareMatrix Int
+testMatrix_04 = SquareMatrix $ fromList (Z :. 8 :. 8) $
+  [  3, -1,  0, 1, -1,  1,  1, -3,
+    -2, -2,  2, 1,  1, -2,  1, -1,
+    -2, -3, -1, 1,  1, -3, -2, -1,
+     1, -2,  2, 0,  1,  0,  2,  0,
+    -1, -3, -1, 3, -3,  0, -1,  2,
+     0,  0, -3, 3, -1, -2, -1,  1,
+    -2,  1, -1, 2,  1, -1, -2,  0,
+    -2,  2,  1, 1,  1,  0,  2, -3]
 --
 -- Main test runner
 --
@@ -124,6 +147,8 @@ tests = testGroup "LinearAlgebra" [
     , testGroup "logDistributional2" [
        testProperty "2x2" (compareLogDistributional2 (Proxy @Double) twoByTwo)
       , testProperty "7x7" (compareLogDistributional2 (Proxy @Double) testMatrix_02)
+      , testProperty "8x8" (compareLogDistributional2 (Proxy @Double) testMatrix_04)
+      , testProperty "11x11" (compareLogDistributional2 (Proxy @Double) testMatrix_03)
       , testProperty "14x14" (compareLogDistributional2 (Proxy @Double) testMatrix_01)
       ,testProperty "roundtrips" (compareLogDistributional2 (Proxy @Double))
     ]