summaryrefslogtreecommitdiff
path: root/lib/Data/Packed/Internal/Vector.hs
blob: 76bd4d1ad67e3a61000a9c1ebbe46de021a68ccf (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
{-# OPTIONS_GHC -fglasgow-exts -fallow-undecidable-instances #-}
-----------------------------------------------------------------------------
-- |
-- Module      :  Data.Packed.Internal.Vector
-- Copyright   :  (c) Alberto Ruiz 2007
-- License     :  GPL-style
--
-- Maintainer  :  Alberto Ruiz <aruiz@um.es>
-- Stability   :  provisional
-- Portability :  portable (uses FFI)
--
-- Vector implementation
--
-----------------------------------------------------------------------------
-- #hide

module Data.Packed.Internal.Vector where

import Data.Packed.Internal.Common
import Foreign
import Complex
import Control.Monad(when)
import Data.List(transpose)
import Debug.Trace(trace)
import Foreign.C.String(peekCString)
import Foreign.C.Types
import Data.Monoid

-- | A one-dimensional array of objects stored in a contiguous memory block.
data Vector t = V { dim  :: Int            -- ^ number of elements
                  , fptr :: ForeignPtr t   -- ^ foreign pointer to the memory block
                  , ptr  :: Ptr t          -- ^ ordinary pointer to the actual starting address (usually the same)
                  }

-- | check the error code and touch foreign ptr of vector arguments (if any)
check :: String -> [Vector a] -> IO Int -> IO ()
check msg ls f = do
    err <- f
    when (err/=0) $ if err > 1024
                      then (error (msg++": "++errorCode err)) -- our errors
                      else do                                 -- GSL errors
                        ps <- gsl_strerror err
                        s <- peekCString ps
                        error (msg++": "++s)
    mapM_ (touchForeignPtr . fptr) ls
    return ()

-- | description of GSL error codes
foreign import ccall "auxi.h gsl_strerror" gsl_strerror :: Int -> IO (Ptr CChar)

-- | signature of foreign functions admitting C-style vectors
type Vc t s = Int -> Ptr t -> s
-- not yet admitted by my haddock version
-- infixr 5 :>
-- type t :> s = Vc t s

-- | adaptation of our vectors to be admitted by foreign functions: @f \/\/ vec v@
vec :: Vector t -> (Vc t s) -> s
vec v f = f (dim v) (ptr v)

-- | allocates memory for a new vector
createVector :: Storable a => Int -> IO (Vector a)
createVector n = do
    when (n <= 0) $ error ("trying to createVector of dim "++show n)
    fp <- mallocForeignPtrArray n
    let p = unsafeForeignPtrToPtr fp
    --putStrLn ("\n---------> V"++show n)
    return $ V n fp p

{- | creates a Vector from a list:

@> fromList [2,3,5,7]
4 |> [2.0,3.0,5.0,7.0]@

-}
fromList :: Storable a => [a] -> Vector a
fromList l = unsafePerformIO $ do
    v <- createVector (length l)
    let f _ p = pokeArray p l >> return 0
    f // vec v // check "fromList" []
    return v

{- | extracts the Vector elements to a list

@> toList (linspace 5 (1,10))
[1.0,3.25,5.5,7.75,10.0]@

-}
toList :: Storable a => Vector a -> [a]
toList v = unsafePerformIO $ peekArray (dim v) (ptr v)

-- | an alternative to 'fromList' with explicit dimension, used also in the instances for Show (Vector a).
(|>) :: (Storable a) => Int -> [a] -> Vector a
infixl 9 |>
n |> l = if length l == n then fromList l else error "|> with wrong size"

-- | access to Vector elements without range checking
at' :: Storable a => Vector a -> Int -> a
at' v n = unsafePerformIO $ peekElemOff (ptr v) n

-- | access to Vector elements with range checking.
at :: Storable a => Vector a -> Int -> a
at v n | n >= 0 && n < dim v = at' v n
       | otherwise          = error "vector index out of range"

{- | takes a number of consecutive elements from a Vector

@> subVector 2 3 (fromList [1..10])
3 |> [3.0,4.0,5.0]@

-}
subVector :: Storable t => Int       -- ^ index of the starting element
                        -> Int       -- ^ number of elements to extract
                        -> Vector t  -- ^ source
                        -> Vector t  -- ^ result
subVector k l (v@V {dim=n, ptr=p, fptr=fp})
    | k<0 || k >= n || k+l > n || l < 0 = error "subVector out of range"
    | otherwise = unsafePerformIO $ do
        r <- createVector l
        let f = copyArray (ptr r) (advancePtr p k) l >> return 0
        f // check "subVector" [v]
        return r

subVector' k l (v@V {dim=n, ptr=p, fptr=fp})
    | k<0 || k >= n || k+l > n || l < 0 = error "subVector out of range"
    | otherwise = v {dim=l, ptr=advancePtr p k}


{- | Reads a vector position:

@> fromList [0..9] \@\> 7
7.0@

-}
(@>) :: Storable t => Vector t -> Int -> t
infixl 9 @>
(@>) = at


{- | creates a new Vector by joining a list of Vectors

@> join [fromList [1..5], constant 1 3]
8 |> [1.0,2.0,3.0,4.0,5.0,1.0,1.0,1.0]@

-}
join :: Storable t => [Vector t] -> Vector t
join [] = error "joining zero vectors"
join as = unsafePerformIO $ do
    let tot = sum (map dim as)
    r@V {fptr = p, ptr = p'} <- createVector tot
    withForeignPtr p $ \_ ->
        joiner as tot p'
    return r
  where joiner [] _ _ = return ()
        joiner (V {dim = n, fptr = b, ptr = q} : cs) _ p = do
            withForeignPtr b  $ \_ -> copyArray p q n
            joiner cs 0 (advancePtr p n)


-- | transforms a complex vector into a real vector with alternating real and imaginary parts 
asReal :: Vector (Complex Double) -> Vector Double
asReal v = V { dim = 2*dim v, fptr =  castForeignPtr (fptr v), ptr = castPtr (ptr v) }

-- | transforms a real vector into a complex vector with alternating real and imaginary parts
asComplex :: Vector Double -> Vector (Complex Double)
asComplex v = V { dim = dim v `div` 2, fptr =  castForeignPtr (fptr v), ptr = castPtr (ptr v) }

----------------------------------------------------------------

-- | map on Vectors
liftVector :: (Storable a, Storable b) => (a-> b) -> Vector a -> Vector b
liftVector  f = fromList . map f . toList

-- | zipWith for Vectors
liftVector2 :: (Storable a, Storable b, Storable c) => (a-> b -> c) -> Vector a -> Vector b -> Vector c
liftVector2 f u v = fromList $ zipWith f (toList u) (toList v)

-----------------------------------------------------------------