2 files changed, 10 insertions, 0 deletions

diff --git a/lib/Numeric/Container.hs b/lib/Numeric/Container.hs
index b3f46de..bad941c 100644
--- a/lib/Numeric/Container.hs
+++ b/lib/Numeric/Container.hs
@@ -128,3 +128,5 @@ instance Mul Vector Matrix Vector where
 (<\>) :: (Field a) => Matrix a -> Vector a -> Vector a
 infixl 7 <\>
 m <\> v = flatten (linearSolveSVD m (reshape 1 v))
+
+--------------------------------------------------------
diff --git a/lib/Numeric/ContainerBoot.hs b/lib/Numeric/ContainerBoot.hs
index 1284639..f628e10 100644
--- a/lib/Numeric/ContainerBoot.hs
+++ b/lib/Numeric/ContainerBoot.hs
@@ -91,6 +91,9 @@ class (Complexable c, Fractional e, Element e) => Container c e where
     divide      :: c e -> c e -> c e
     equal       :: c e -> c e -> Bool
     --
+    -- element by element inverse tangent
+    arctan      :: c e -> c e ->  c e
+    --
     -- | cannot implement instance Functor because of Element class constraint
     cmap        :: (Element a, Element b) => (a -> b) -> c a -> c b
     -- | constant structure of given size
@@ -130,6 +133,7 @@ instance Container Vector Float where
     mul = vectorZipF Mul
     divide = vectorZipF Div
     equal u v = dim u == dim v && maxElement (vectorMapF Abs (sub u v)) == 0.0
+    arctan = vectorZipF ATan2
     scalar x = fromList [x]
     konst = constantD
     build = buildV
@@ -152,6 +156,7 @@ instance Container Vector Double where
     mul = vectorZipR Mul
     divide = vectorZipR Div
     equal u v = dim u == dim v && maxElement (vectorMapR Abs (sub u v)) == 0.0
+    arctan = vectorZipR ATan2
     scalar x = fromList [x]
     konst = constantD
     build = buildV
@@ -174,6 +179,7 @@ instance Container Vector (Complex Double) where
     mul = vectorZipC Mul
     divide = vectorZipC Div
     equal u v = dim u == dim v && maxElement (mapVector magnitude (sub u v)) == 0.0
+    arctan = vectorZipC ATan2
     scalar x = fromList [x]
     konst = constantD
     build = buildV
@@ -196,6 +202,7 @@ instance Container Vector (Complex Float) where
     mul = vectorZipQ Mul
     divide = vectorZipQ Div
     equal u v = dim u == dim v && maxElement (mapVector magnitude (sub u v)) == 0.0
+    arctan = vectorZipQ ATan2
     scalar x = fromList [x]
     konst = constantD
     build = buildV
@@ -220,6 +227,7 @@ instance (Container Vector a) => Container Matrix a where
     mul = liftMatrix2 mul
     divide = liftMatrix2 divide
     equal a b = cols a == cols b && flatten a `equal` flatten b
+    arctan = liftMatrix2 arctan
     scalar x = (1><1) [x]
     konst v (r,c) = reshape c (konst v (r*c))
     build = buildM