Copyright | (c) Edward Kmett 2010-2013 |
---|---|
License | BSD3 |
Maintainer | ekmett@gmail.com |
Stability | experimental |
Portability | DeriveDataTypeable |
Safe Haskell | Safe |
Language | Haskell98 |
Interval arithmetic
- data Interval a
- (...) :: Ord a => a -> a -> Interval a
- interval :: Ord a => a -> a -> Maybe (Interval a)
- whole :: Fractional a => Interval a
- singleton :: a -> Interval a
- member :: Ord a => a -> Interval a -> Bool
- notMember :: Ord a => a -> Interval a -> Bool
- elem :: Ord a => a -> Interval a -> Bool
- notElem :: Ord a => a -> Interval a -> Bool
- inf :: Interval a -> a
- sup :: Interval a -> a
- singular :: Ord a => Interval a -> Bool
- width :: Num a => Interval a -> a
- midpoint :: Fractional a => Interval a -> a
- distance :: (Num a, Ord a) => Interval a -> Interval a -> a
- intersection :: Ord a => Interval a -> Interval a -> Maybe (Interval a)
- hull :: Ord a => Interval a -> Interval a -> Interval a
- bisect :: Fractional a => Interval a -> (Interval a, Interval a)
- bisectIntegral :: Integral a => Interval a -> (Interval a, Interval a)
- magnitude :: (Num a, Ord a) => Interval a -> a
- mignitude :: (Num a, Ord a) => Interval a -> a
- contains :: Ord a => Interval a -> Interval a -> Bool
- isSubsetOf :: Ord a => Interval a -> Interval a -> Bool
- certainly :: Ord a => (forall b. Ord b => b -> b -> Bool) -> Interval a -> Interval a -> Bool
- (<!) :: Ord a => Interval a -> Interval a -> Bool
- (<=!) :: Ord a => Interval a -> Interval a -> Bool
- (==!) :: Eq a => Interval a -> Interval a -> Bool
- (>=!) :: Ord a => Interval a -> Interval a -> Bool
- (>!) :: Ord a => Interval a -> Interval a -> Bool
- possibly :: Ord a => (forall b. Ord b => b -> b -> Bool) -> Interval a -> Interval a -> Bool
- (<?) :: Ord a => Interval a -> Interval a -> Bool
- (<=?) :: Ord a => Interval a -> Interval a -> Bool
- (==?) :: Ord a => Interval a -> Interval a -> Bool
- (>=?) :: Ord a => Interval a -> Interval a -> Bool
- (>?) :: Ord a => Interval a -> Interval a -> Bool
- clamp :: Ord a => Interval a -> a -> a
- inflate :: (Num a, Ord a) => a -> Interval a -> Interval a
- deflate :: (Fractional a, Ord a) => a -> Interval a -> Interval a
- scale :: (Fractional a, Ord a) => a -> Interval a -> Interval a
- symmetric :: (Num a, Ord a) => a -> Interval a
- idouble :: Interval Double -> Interval Double
- ifloat :: Interval Float -> Interval Float
- iquot :: Integral a => Interval a -> Interval a -> Interval a
- irem :: Integral a => Interval a -> Interval a -> Interval a
- idiv :: Integral a => Interval a -> Interval a -> Interval a
- imod :: Integral a => Interval a -> Interval a -> Interval a
Documentation
Foldable Interval # | |
Generic1 Interval # | |
Eq a => Eq (Interval a) # | |
(RealFloat a, Ord a) => Floating (Interval a) # | Transcendental functions for intervals. conservative (exp :: Double -> Double) exp conservativeExceptNaN (log :: Double -> Double) log conservative (sin :: Double -> Double) sin conservative (cos :: Double -> Double) cos conservative (tan :: Double -> Double) tan conservativeExceptNaN (asin :: Double -> Double) asin conservativeExceptNaN (acos :: Double -> Double) acos conservative (atan :: Double -> Double) atan conservative (sinh :: Double -> Double) sinh conservative (cosh :: Double -> Double) cosh conservative (tanh :: Double -> Double) tanh conservativeExceptNaN (asinh :: Double -> Double) asinh conservativeExceptNaN (acosh :: Double -> Double) acosh conservativeExceptNaN (atanh :: Double -> Double) atanh
|
(Fractional a, Ord a) => Fractional (Interval a) # | Fractional instance for intervals. ys /= singleton 0 ==> conservative2 ((/) :: Double -> Double -> Double) (/) xs ys xs /= singleton 0 ==> conservative (recip :: Double -> Double) recip xs |
Data a => Data (Interval a) # | |
(Num a, Ord a) => Num (Interval a) # | Num instance for intervals. conservative2 ((+) :: Double -> Double -> Double) (+) conservative2 ((-) :: Double -> Double -> Double) (-) conservative2 ((*) :: Double -> Double -> Double) (*) conservative (abs :: Double -> Double) abs |
Ord a => Ord (Interval a) # | |
Real a => Real (Interval a) # |
|
RealFloat a => RealFloat (Interval a) # | We have to play some semantic games to make these methods make sense. Most compute with the midpoint of the interval. |
RealFrac a => RealFrac (Interval a) # | |
Show a => Show (Interval a) # | |
Generic (Interval a) # | |
type Rep1 Interval # | |
type Rep (Interval a) # | |
(...) :: Ord a => a -> a -> Interval a infix 3 #
Create a non-empty interval, turning it around if necessary
whole :: Fractional a => Interval a #
The whole real number line
>>>
whole
-Infinity ... Infinity
(x :: Double) `elem` whole
singleton :: a -> Interval a #
A singleton point
>>>
singleton 1
1 ... 1
x `elem` (singleton x)
x /= y ==> y `notElem` (singleton x)
member :: Ord a => a -> Interval a -> Bool #
Determine if a point is in the interval.
>>>
member 3.2 (1.0 ... 5.0)
True
>>>
member 5 (1.0 ... 5.0)
True
>>>
member 1 (1.0 ... 5.0)
True
>>>
member 8 (1.0 ... 5.0)
False
notMember :: Ord a => a -> Interval a -> Bool #
Determine if a point is not included in the interval
>>>
notMember 8 (1.0 ... 5.0)
True
>>>
notMember 1.4 (1.0 ... 5.0)
False
elem :: Ord a => a -> Interval a -> Bool #
Deprecated: Use member
instead.
Determine if a point is in the interval.
>>>
elem 3.2 (1.0 ... 5.0)
True
>>>
elem 5 (1.0 ... 5.0)
True
>>>
elem 1 (1.0 ... 5.0)
True
>>>
elem 8 (1.0 ... 5.0)
False
notElem :: Ord a => a -> Interval a -> Bool #
Deprecated: Use notMember
instead.
Determine if a point is not included in the interval
>>>
notElem 8 (1.0 ... 5.0)
True
>>>
notElem 1.4 (1.0 ... 5.0)
False
The infinumum (lower bound) of an interval
>>>
inf (1 ... 20)
1
min x y == inf (x ... y)
inf x <= sup x
The supremum (upper bound) of an interval
>>>
sup (1 ... 20)
20
sup x `elem` x
max x y == sup (x ... y)
inf x <= sup x
singular :: Ord a => Interval a -> Bool #
Is the interval a singleton point? N.B. This is fairly fragile and likely will not hold after even a few operations that only involve singletons
>>>
singular (singleton 1)
True
>>>
singular (1.0 ... 20.0)
False
width :: Num a => Interval a -> a #
Calculate the width of an interval.
>>>
width (1 ... 20)
19
>>>
width (singleton 1)
0
0 <= width x
midpoint :: Fractional a => Interval a -> a #
Nearest point to the midpoint of the interval.
>>>
midpoint (10.0 ... 20.0)
15.0
>>>
midpoint (singleton 5.0)
5.0
midpoint x `elem` (x :: Interval Double)
distance :: (Num a, Ord a) => Interval a -> Interval a -> a #
Hausdorff distance between intervals.
>>>
distance (1 ... 7) (6 ... 10)
0
>>>
distance (1 ... 7) (15 ... 24)
8
>>>
distance (1 ... 7) (-10 ... -2)
3
commutative (distance :: Interval Double -> Interval Double -> Double)
0 <= distance x y
intersection :: Ord a => Interval a -> Interval a -> Maybe (Interval a) #
Calculate the intersection of two intervals.
>>>
intersection (1 ... 10 :: Interval Double) (5 ... 15 :: Interval Double)
Just (5.0 ... 10.0)
hull :: Ord a => Interval a -> Interval a -> Interval a #
Calculate the convex hull of two intervals
>>>
hull (0 ... 10 :: Interval Double) (5 ... 15 :: Interval Double)
0.0 ... 15.0
>>>
hull (15 ... 85 :: Interval Double) (0 ... 10 :: Interval Double)
0.0 ... 85.0
conservative2 const hull
conservative2 (flip const) hull
bisect :: Fractional a => Interval a -> (Interval a, Interval a) #
Bisect an interval at its midpoint.
>>>
bisect (10.0 ... 20.0)
(10.0 ... 15.0,15.0 ... 20.0)
>>>
bisect (singleton 5.0)
(5.0 ... 5.0,5.0 ... 5.0)
let (a, b) = bisect (x :: Interval Double) in sup a == inf b
let (a, b) = bisect (x :: Interval Double) in inf a == inf x
let (a, b) = bisect (x :: Interval Double) in sup b == sup x
magnitude :: (Num a, Ord a) => Interval a -> a #
Magnitude
>>>
magnitude (1 ... 20)
20
>>>
magnitude (-20 ... 10)
20
>>>
magnitude (singleton 5)
5
0 <= magnitude x
mignitude :: (Num a, Ord a) => Interval a -> a #
"mignitude"
>>>
mignitude (1 ... 20)
1
>>>
mignitude (-20 ... 10)
0
>>>
mignitude (singleton 5)
5
0 <= mignitude x
contains :: Ord a => Interval a -> Interval a -> Bool #
Check if interval X
totally contains interval Y
>>>
(20 ... 40 :: Interval Double) `contains` (25 ... 35 :: Interval Double)
True
>>>
(20 ... 40 :: Interval Double) `contains` (15 ... 35 :: Interval Double)
False
isSubsetOf :: Ord a => Interval a -> Interval a -> Bool #
Flipped version of contains
. Check if interval X
a subset of interval Y
>>>
(25 ... 35 :: Interval Double) `isSubsetOf` (20 ... 40 :: Interval Double)
True
>>>
(20 ... 40 :: Interval Double) `isSubsetOf` (15 ... 35 :: Interval Double)
False
certainly :: Ord a => (forall b. Ord b => b -> b -> Bool) -> Interval a -> Interval a -> Bool #
For all x
in X
, y
in Y
. x
op
y
(<!) :: Ord a => Interval a -> Interval a -> Bool #
For all x
in X
, y
in Y
. x
<
y
>>>
(5 ... 10 :: Interval Double) <! (20 ... 30 :: Interval Double)
True
>>>
(5 ... 10 :: Interval Double) <! (10 ... 30 :: Interval Double)
False
>>>
(20 ... 30 :: Interval Double) <! (5 ... 10 :: Interval Double)
False
(<=!) :: Ord a => Interval a -> Interval a -> Bool #
For all x
in X
, y
in Y
. x
<=
y
>>>
(5 ... 10 :: Interval Double) <=! (20 ... 30 :: Interval Double)
True
>>>
(5 ... 10 :: Interval Double) <=! (10 ... 30 :: Interval Double)
True
>>>
(20 ... 30 :: Interval Double) <=! (5 ... 10 :: Interval Double)
False
(==!) :: Eq a => Interval a -> Interval a -> Bool #
For all x
in X
, y
in Y
. x
==
y
Only singleton intervals or empty intervals can return true
>>>
(singleton 5 :: Interval Double) ==! (singleton 5 :: Interval Double)
True
>>>
(5 ... 10 :: Interval Double) ==! (5 ... 10 :: Interval Double)
False
(>=!) :: Ord a => Interval a -> Interval a -> Bool #
For all x
in X
, y
in Y
. x
>=
y
>>>
(20 ... 40 :: Interval Double) >=! (10 ... 20 :: Interval Double)
True
>>>
(5 ... 20 :: Interval Double) >=! (15 ... 40 :: Interval Double)
False
(>!) :: Ord a => Interval a -> Interval a -> Bool #
For all x
in X
, y
in Y
. x
>
y
>>>
(20 ... 40 :: Interval Double) >! (10 ... 19 :: Interval Double)
True
>>>
(5 ... 20 :: Interval Double) >! (15 ... 40 :: Interval Double)
False
possibly :: Ord a => (forall b. Ord b => b -> b -> Bool) -> Interval a -> Interval a -> Bool #
Does there exist an x
in X
, y
in Y
such that x
?op
y
(<?) :: Ord a => Interval a -> Interval a -> Bool #
Does there exist an x
in X
, y
in Y
such that x
?<
y
(<=?) :: Ord a => Interval a -> Interval a -> Bool #
Does there exist an x
in X
, y
in Y
such that x
?<=
y
(==?) :: Ord a => Interval a -> Interval a -> Bool #
Does there exist an x
in X
, y
in Y
such that x
?==
y
(>=?) :: Ord a => Interval a -> Interval a -> Bool #
Does there exist an x
in X
, y
in Y
such that x
?>=
y
(>?) :: Ord a => Interval a -> Interval a -> Bool #
Does there exist an x
in X
, y
in Y
such that x
?>
y
clamp :: Ord a => Interval a -> a -> a #
The nearest value to that supplied which is contained in the interval.
(clamp xs y) `elem` xs
inflate :: (Num a, Ord a) => a -> Interval a -> Interval a #
Inflate an interval by enlarging it at both ends.
>>>
inflate 3 (-1 ... 7)
-4 ... 10
>>>
inflate (-2) (0 ... 4)
-2 ... 6
inflate x i `contains` i
deflate :: (Fractional a, Ord a) => a -> Interval a -> Interval a #
Deflate an interval by shrinking it from both ends. Note that in cases that would result in an empty interval, the result is a singleton interval at the midpoint.
>>>
deflate 3.0 (-4.0 ... 10.0)
-1.0 ... 7.0
>>>
deflate 2.0 (-1.0 ... 1.0)
0.0 ... 0.0
scale :: (Fractional a, Ord a) => a -> Interval a -> Interval a #
Scale an interval about its midpoint.
>>>
scale 1.1 (-6.0 ... 4.0)
-6.5 ... 4.5
>>>
scale (-2.0) (-1.0 ... 1.0)
-2.0 ... 2.0
abs x >= 1 ==> (scale (x :: Double) i) `contains` i
forAll (choose (0,1)) $ \x -> abs x <= 1 ==> i `contains` (scale (x :: Double) i)
symmetric :: (Num a, Ord a) => a -> Interval a #
Construct a symmetric interval.
>>>
symmetric 3
-3 ... 3
>>>
symmetric (-2)
-2 ... 2
x `elem` symmetric x
0 `elem` symmetric x
idouble :: Interval Double -> Interval Double #
id function. Useful for type specification
>>>
:t idouble (1 ... 3)
idouble (1 ... 3) :: Interval Double
ifloat :: Interval Float -> Interval Float #
id function. Useful for type specification
>>>
:t ifloat (1 ... 3)
ifloat (1 ... 3) :: Interval Float