From: Michael Orlitzky Date: Sun, 24 Feb 2013 00:04:51 +0000 (-0500) Subject: Add the delete function to Vector.hs. X-Git-Url: https://gitweb.michael.orlitzky.com/?a=commitdiff_plain;h=d86da7a71b498a24b544ded9ad7191707fd0a123;p=numerical-analysis.git Add the delete function to Vector.hs. --- diff --git a/src/Linear/Vector.hs b/src/Linear/Vector.hs index aba9e5f..a7885e4 100644 --- a/src/Linear/Vector.hs +++ b/src/Linear/Vector.hs @@ -14,8 +14,10 @@ import Data.Vector.Fixed ( N2, N3, N4, + S, Vector(..), construct, + fromList, inspect, toList, ) @@ -31,25 +33,25 @@ import qualified Data.Vector.Fixed as V ( -- constructors, so you can pattern match out the individual -- components. -data D1 a = D1 a +data D1 a = D1 a deriving (Show, Eq) type instance Dim D1 = N1 instance Vector D1 a where inspect (D1 x) (Fun f) = f x construct = Fun D1 -data D2 a = D2 a a +data D2 a = D2 a a deriving (Show, Eq) type instance Dim D2 = N2 instance Vector D2 a where inspect (D2 x y) (Fun f) = f x y construct = Fun D2 -data D3 a = D3 a a a +data D3 a = D3 a a a deriving (Show, Eq) type instance Dim D3 = N3 instance Vector D3 a where inspect (D3 x y z) (Fun f) = f x y z construct = Fun D3 -data D4 a = D4 a a a a +data D4 a = D4 a a a a deriving (Show, Eq) type instance Dim D4 = N4 instance Vector D4 a where inspect (D4 w x y z) (Fun f) = f w x y z @@ -81,3 +83,19 @@ instance Vector D4 a where (!?) v1 idx | idx < 0 || idx >= V.length v1 = Nothing | otherwise = Just $ v1 ! idx + + +-- | Remove an element of the given vector. +-- +-- Examples: +-- +-- >>> let b = D3 1 2 3 +-- >>> delete b 1 :: D2 Int +-- D2 1 3 +-- +delete :: (Vector v a, Vector w a, Dim v ~ S (Dim w)) => v a -> Int -> w a +delete v1 idx = + fromList $ (lhalf ++ rhalf') + where + (lhalf, rhalf) = splitAt idx (toList v1) + rhalf' = tail rhalf