From b52e7d3c7e4ea85ab74166926e9f66697a074aae Mon Sep 17 00:00:00 2001
From: Alberto Ruiz <aruiz@um.es>
Date: Sun, 1 Jun 2008 11:39:07 +0000
Subject: added updateVector

---
 lib/Data/Packed/Internal/Vector.hs | 20 ++++++++++++++++++++
 lib/Data/Packed/Vector.hs          |  1 +
 2 files changed, 21 insertions(+)

(limited to 'lib/Data')

diff --git a/lib/Data/Packed/Internal/Vector.hs b/lib/Data/Packed/Internal/Vector.hs
index 1075e64..5a42f9d 100644
--- a/lib/Data/Packed/Internal/Vector.hs
+++ b/lib/Data/Packed/Internal/Vector.hs
@@ -146,3 +146,23 @@ liftVector2 :: (Storable a, Storable b, Storable c) => (a-> b -> c) -> Vector a
 liftVector2 f u v = fromList $ zipWith f (toList u) (toList v)
 
 -----------------------------------------------------------------
+
+{- | creates a new vector with a desired position updated with a modification function
+
+@> updateVector 3 (+7) (fromList [1..5])
+5 |> [1.0,2.0,3.0,11.0,5.0]@
+
+-}
+updateVector :: Storable t => Int       -- ^ position
+                           -> (t->t)    -- ^ modification function
+                           -> Vector t  -- ^ source
+                           -> Vector t  -- ^ result
+updateVector k h (v@V {dim=n})
+    | k<0 || k >= n = error $ "updateVector out of range (dim="++show n++", pos="++show k++")"
+    | otherwise = unsafePerformIO $ do
+        r <- createVector n
+        let f _ s _ d =  copyArray d s n
+                      >> pokeElemOff d k (h (v`at'`k))
+                      >> return 0
+        app2 f vec v vec r "updateVector"
+        return r
diff --git a/lib/Data/Packed/Vector.hs b/lib/Data/Packed/Vector.hs
index 6415c5c..9e3c206 100644
--- a/lib/Data/Packed/Vector.hs
+++ b/lib/Data/Packed/Vector.hs
@@ -17,6 +17,7 @@ module Data.Packed.Vector (
     fromList, (|>), toList,
     dim, (@>),
     subVector, join,
+    updateVector,
     constant, linspace,
     vectorMax, vectorMin, vectorMaxIndex, vectorMinIndex,
     liftVector, liftVector2
-- 
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