linear 0.6 → 0.6.1

raw patch · 2 files changed

+16/−10 lines, 2 filesnew-uploader

Files

• linear.cabal +1/−1
• src/Linear/Vector.hs +15/−9

@@ -1,6 +1,6 @@ name:          linear category:      Math, Algebra-version:       0.6+version:       0.6.1 license:       BSD3 cabal-version: >= 1.8 license-file:  LICENSE

@@ -17,11 +17,14 @@   , (*^)   , (^/)   , lerp-  -- , basis-  -- , basisFor+  , basis+  , basisFor   ) where  import Control.Applicative+import Data.Foldable (foldMap)+import Data.Monoid (Sum(..))+import Data.Traversable (Traversable, mapAccumL)  -- $setup -- >>> import Control.Lens@@ -80,20 +83,23 @@ lerp alpha u v = alpha *^ u ^+^ (1 - alpha) *^ v {-# INLINE lerp #-} -{-+-- @setElement i x v@ sets the @i@'th element of @v@ to @x@.+setElement :: Traversable t => Int -> a -> t a -> t a+setElement i x = snd . mapAccumL aux 0+  where aux j y = let j' = j + 1 +                      y' = if i == j then x else y+                  in j' `seq` (j', y')  -- | Produce a default basis for a vector space. If the dimensionality -- of the vector space is not statically known, see 'basisFor'. basis :: (Applicative t, Traversable t, Num a) => [t a]-basis = [ set (element k) 1 zero | k <- [0..lengthOf folded zero - 1]]+basis = [ setElement k 1 zero | k <- [0..n - 1] ]   where zero = pure 0+        n = getSum $ foldMap (const (Sum 1)) zero  -- | Produce a default basis for a vector space from which the -- argument is drawn. basisFor :: (Traversable t, Enum a, Num a) => t a -> [t a]-basisFor v = map aux [0..n-1]+basisFor v = [ setElement k 1 z | k <- [0..n-1] ]   where z = 0 <$ v-        n = lengthOf folded z-        aux i = z & element i .~ 1---}+        n = getSum $ foldMap (const (Sum 1)) v