Maintainer	Ziyang Liu <free@cofree.io>
Safe Haskell	None
Language	Haskell2010

Math.Extras.Double

Contents

Constant double values
Fuzzy comparison
Rounding
Predicates
Conversion

Description

Arithmetic on doubles. Some functions use more general types than Double.

Synopsis

positiveInfinity :: Double
negativeInfinity :: Double
nan :: Double
type Tolerance = Double
fuzzyEq :: Tolerance -> Double -> Double -> Bool
fuzzyCompare :: Tolerance -> Double -> Double -> Ordering
(~=) :: Double -> Double -> Bool
(/~=) :: Double -> Double -> Bool
data RoundingMode
- = Up
- | Down
- | Ceiling
- | Floor
- | HalfUp
- | HalfDown
- | HalfEven
roundToInteger :: RoundingMode -> Double -> Integer
saturatedRound :: forall a. (Bounded a, Integral a) => RoundingMode -> Double -> a
isFinite :: RealFloat a => a -> Bool
isInteger :: (Eq a, Num a, RealFloat a) => a -> Bool
toInt64RawBits :: Double -> Int64
toWord64RawBits :: Double -> Word64
fromInt64RawBits :: Int64 -> Double
fromWord64RawBits :: Int64 -> Double

Constant double values

positiveInfinity :: Double Source #

A constant holding the positive infinity of type Double.

negativeInfinity :: Double Source #

A constant holding the negative infinity of type Double.

nan :: Double Source #

A constant holding a NaN value of type Double.

Fuzzy comparison

type Tolerance = Double Source #

fuzzyEq :: Tolerance -> Double -> Double -> Bool Source #

Returns True if the difference of the two numbers are no more than abs(tolerance).

All NaNs are fuzzily equal.
With finite tolerance, positiveInfinity and negativeInfinity are fuzzily equal only to themselves.
With positiveInfinity or negativeInfinity tolerance, all non-NaN values are fuzzily equal.
NaN tolerance behaves the same as zero tolerance.

fuzzyEq tolerance is reflexive and symmetric, but not transitive unless tolerance is zero, positiveInfinity, negativeInfinity, or NaN.

fuzzyCompare :: Tolerance -> Double -> Double -> Ordering Source #

Compare two Doubles with a tolerance.

If fuzzyEq tolerance x y then fuzzyCompare tolerance x y == EQ; otherwise fuzzyCompare tolerance x y == compare x y.

(~=) :: Double -> Double -> Bool Source #

(~=) is equivalent to fuzzyEq 1.0e-6.

(/~=) :: Double -> Double -> Bool Source #

x /~= y is equivalent to not (x ~= y).

Rounding

data RoundingMode Source #

Constructors

Up	Round away from 0
Down	Round towards 0
Ceiling	Round towards positive infinity
Floor	Round towards negative infinity
HalfUp	Round towards nearest integer; round `Up` in case of a tie
HalfDown	Round towards nearest integer; round `Down` in case of a tie
HalfEven	Round towards nearest integer; round towards the even neighbor in case of a tie

Instances

Eq RoundingMode Source #
Instance details Defined in Math.Extras.Double Methods (==) :: RoundingMode -> RoundingMode -> Bool # (/=) :: RoundingMode -> RoundingMode -> Bool #
Ord RoundingMode Source #
Instance details Defined in Math.Extras.Double Methods compare :: RoundingMode -> RoundingMode -> Ordering # (<) :: RoundingMode -> RoundingMode -> Bool # (<=) :: RoundingMode -> RoundingMode -> Bool # (>) :: RoundingMode -> RoundingMode -> Bool # (>=) :: RoundingMode -> RoundingMode -> Bool # max :: RoundingMode -> RoundingMode -> RoundingMode # min :: RoundingMode -> RoundingMode -> RoundingMode #
Show RoundingMode Source #
Instance details Defined in Math.Extras.Double Methods showsPrec :: Int -> RoundingMode -> ShowS # show :: RoundingMode -> String # showList :: [RoundingMode] -> ShowS #

roundToInteger :: RoundingMode -> Double -> Integer Source #

Round a Double to an Integer using the specified RoundingMode.

saturatedRound :: forall a. (Bounded a, Integral a) => RoundingMode -> Double -> a Source #

Round a Double to an integral number using the specified RoundingMode. Returns maxBound and minBound in case of overflow and underflow, respectively.

Predicates

isFinite :: RealFloat a => a -> Bool Source #

Returns False for NaN and infinity, and True otherwise.

isInteger :: (Eq a, Num a, RealFloat a) => a -> Bool Source #

Returns True if the input represents an integer.

Conversion

toInt64RawBits :: Double -> Int64 Source #

Returns an Int64 with the same bit representation as the given Double.

toWord64RawBits :: Double -> Word64 Source #

Returns a Word64 with the same bit representation as the given Double.

fromInt64RawBits :: Int64 -> Double Source #

Returns a Double with the same bit representation as the given Int64.

fromWord64RawBits :: Int64 -> Double Source #

Returns a Double with the same bit representation as the given Word64.