summaryrefslogtreecommitdiff
path: root/lib/Numeric/LinearAlgebra/Tests/Properties.hs
blob: 45b03a2f73394cd6490473aded1fc56ef02a538f (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
{-# OPTIONS #-}
-----------------------------------------------------------------------------
{- |
Module      :  Numeric.LinearAlgebra.Tests.Properties
Copyright   :  (c) Alberto Ruiz 2008
License     :  GPL-style

Maintainer  :  Alberto Ruiz (aruiz at um dot es)
Stability   :  provisional
Portability :  portable

Testing properties.

-}

module Numeric.LinearAlgebra.Tests.Properties (
    dist, (|~|), (~:), Aprox((:~)),
    zeros, ones,
    square,
    unitary,
    hermitian,
    wellCond,
    positiveDefinite,
    upperTriang,
    upperHessenberg,
    luProp,
    invProp,
    pinvProp,
    detProp,
    nullspaceProp,
    svdProp1, svdProp2,
    eigProp, eigSHProp,
    qrProp,
    hessProp,
    schurProp1, schurProp2,
    cholProp,
    expmDiagProp,
    multProp1, multProp2,
    linearSolveProp
) where

import Numeric.LinearAlgebra
import Test.QuickCheck
-- import Debug.Trace

-- debug x = trace (show x) x

-- relative error
dist :: (Normed t, Num t) => t -> t -> Double
dist a b = r
    where norm = pnorm Infinity
          na = norm a
          nb = norm b
          nab = norm (a-b)
          mx = max na nb
          mn = min na nb
          r = if mn < eps
                then mx
                else nab/mx

infixl 4 |~|
a |~| b = a :~10~: b
--a |~| b = dist a b < 10^^(-10)

data Aprox a = (:~) a Int
(~:) :: (Normed a, Num a) => Aprox a -> a -> Bool
a :~n~: b = dist a b < 10^^(-n)

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

square m = rows m == cols m

unitary m = square m && m <> ctrans m |~| ident (rows m)

hermitian m = square m && m |~| ctrans m

wellCond m = rcond m > 1/100

positiveDefinite m = minimum (toList e) > 0
    where (e,_v) = eigSH m

upperTriang m = rows m == 1 || down == z
    where down = fromList $ concat $ zipWith drop [1..] (toLists (ctrans m))
          z = constant 0 (dim down)

upperHessenberg m = rows m < 3 || down == z
    where down = fromList $ concat $ zipWith drop [2..] (toLists (ctrans m))
          z = constant 0 (dim down)

zeros (r,c) = reshape c (constant 0 (r*c))

ones (r,c) = zeros (r,c) + 1

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

luProp m = m |~| p <> l <> u && f (det p) |~| f s
    where (l,u,p,s) = lu m
          f x = fromList [x]

invProp m = m <> inv m |~| ident (rows m)

pinvProp m =  m <> p <> m |~| m
           && p <> m <> p |~| p
           && hermitian (m<>p)
           && hermitian (p<>m)
    where p = pinv m

detProp m = s d1 |~| s d2
    where d1 = det m
          d2 = det' * det q
          det' = product $ toList $ takeDiag r
          (q,r) = qr m
          s x = fromList [x]

nullspaceProp m = null nl `trivial` (null nl || m <> n |~| zeros (r,c))
    where nl = nullspacePrec 1 m
          n = fromColumns nl
          r = rows m
          c = cols m - rank m

svdProp1 m = u <> real d <> trans v |~| m
          && unitary u && unitary v
    where (u,d,v) = full svd m

svdProp2 m = (m |~| 0) `trivial` ((m |~| 0) || u <> real (diag s) <> trans v |~| m)
    where (u,s,v) = economy svd m

eigProp m = complex m <> v |~| v <> diag s
    where (s, v) = eig m

eigSHProp m = m <> v |~| v <> real (diag s)
              && unitary v
              && m |~| v <> real (diag s) <> ctrans v
    where (s, v) = eigSH m

qrProp m = q <> r |~| m && unitary q && upperTriang r
    where (q,r) = qr m

hessProp m = m |~| p <> h <> ctrans p && unitary p && upperHessenberg h
    where (p,h) = hess m

schurProp1 m = m |~| u <> s <> ctrans u && unitary u && upperTriang s
    where (u,s) = schur m

schurProp2 m = m |~| u <> s <> ctrans u && unitary u && upperHessenberg s -- fixme
    where (u,s) = schur m

cholProp m = m |~| ctrans c <> c && upperTriang c
    where c = chol m
          -- pos = positiveDefinite m

expmDiagProp m = expm (logm m) :~ 7 ~: complex m
    where logm = matFunc log

multProp1 (a,b) = a <> b |~| mulH a b

multProp2 (a,b) = ctrans (a <> b) |~| ctrans b <> ctrans a

linearSolveProp f m = f m m |~| ident (rows m)