Create Data.NumIdr.Multiply

src/Data/NumIdr/Matrix.idr

@@ -1,7 +1,9 @@
 module Data.NumIdr.Matrix
 
 import Data.Vect
+import Data.NumIdr.Multiply
 import public Data.NumIdr.Array
+import Data.NumIdr.Vector
 
 %default total
 
@@ -10,6 +12,9 @@ public export
 Matrix : Nat -> Nat -> Type -> Type
 Matrix m n = Array [m,n]
 
+public export
+Matrix' : Nat -> Type -> Type
+Matrix' n = Matrix n n
 
 
 --------------------------------------------------------------------------------
@@ -29,13 +34,37 @@ matrix = matrix' COrder
 export
 repeatDiag : {m, n : _} -> (diag, other : a) -> Matrix m n a
 repeatDiag d o = fromFunction [m,n]
-   (\[i,j] => if finToNat i == finToNat j then d else o)
+   (\[i,j] => if i `eq` j then d else o)
+  where
+    eq : {0 m,n : Nat} -> Fin m -> Fin n -> Bool
+    eq FZ FZ = True
+    eq (FS x) (FS y) = eq x y
+    eq FZ (FS _) = False
+    eq (FS _) FZ = False
+
+export
+fromDiag : {m, n : _} -> (diag : Vect (minimum m n) a) -> (other : a) -> Matrix m n a
+fromDiag ds o = fromFunction [m,n] (\[i,j] => maybe o (`index` ds) $ i `eq` j)
+  where
+    eq : {0 m,n : Nat} -> Fin m -> Fin n -> Maybe (Fin (minimum m n))
+    eq FZ FZ = Just FZ
+    eq (FS x) (FS y) = map FS (eq x y)
+    eq FZ (FS _) = Nothing
+    eq (FS _) FZ = Nothing
+
 
 export
 identity : Num a => {n : _} -> Matrix n n a
 identity = repeatDiag 1 0
 
 
+export
+scaling : Num a => {n : _} -> a -> Matrix n n a
+scaling x = repeatDiag x 0
+
+export
+rotation2D : Double -> Matrix' 2 Double
+rotation2D a = matrix [[cos a, - sin a], [sin a, cos a]]
 
 
 --------------------------------------------------------------------------------
@@ -47,7 +76,29 @@ export
 index : Fin m -> Fin n -> Matrix m n a -> a
 index m n = index [m,n]
 
+export
+indexMaybe : Nat -> Nat -> Matrix m n a -> Maybe a
+indexMaybe m n = indexMaybe [m,n]
+
+
+export
+getRow : Fin m -> Matrix m n a -> Vector n a
+getRow r mat = rewrite sym (minusZeroRight n) in indexRange [One r, All] mat
+
+export
+getColumn : Fin n -> Matrix m n a -> Vector m a
+getColumn c mat = rewrite sym (minusZeroRight m) in indexRange [All, One c] mat
+
 
 --------------------------------------------------------------------------------
 -- Operations
 --------------------------------------------------------------------------------
+
+export
+vstack : Matrix m n a -> Matrix m' n a -> Matrix (m + m') n a
+vstack = stack 0
+
+export
+hstack : Matrix m n a -> Matrix m n' a -> Matrix m (n + n') a
+hstack = stack 1
+