Numeric

base-4.12.0.0: Basic libraries

Copyright | (c) The University of Glasgow 2002
License | BSD-style (see the file libraries/base/LICENSE)
Maintainer | libraries@haskell.org
Stability | provisional
Portability | portable
Safe Haskell | Trustworthy
Language | Haskell2010

Numeric

Contents

- Showing
- Reading
- Miscellaneous

Description

Odds and ends, mostly functions for reading and showing `RealFloat`-like kind of values.

Synopsis

- showSigned :: Real a => (a -> ShowS) -> Int -> a -> ShowS
- showIntAtBase :: (Integral a, Show a) => a -> (Int -> Char) -> a -> ShowS
- showInt :: Integral a => a -> ShowS
- showHex :: (Integral a, Show a) => a -> ShowS
- showOct :: (Integral a, Show a) => a -> ShowS
- showEFloat :: RealFloat a => Maybe Int -> a -> ShowS
- showFFloat :: RealFloat a => Maybe Int -> a -> ShowS
- showGFloat :: RealFloat a => Maybe Int -> a -> ShowS
- showFFloatAlt :: RealFloat a => Maybe Int -> a -> ShowS
- showGFloatAlt :: RealFloat a => Maybe Int -> a -> ShowS
- showFloat :: RealFloat a => a -> ShowS
- showHFloat :: RealFloat a => a -> ShowS
- floatToDigits :: RealFloat a => Integer -> a -> ([Int], Int)
- readSigned :: Real a => ReadS a -> ReadS a
- readInt :: Num a => a -> (Char -> Bool) -> (Char -> Int) -> ReadS a
- readDec :: (Eq a, Num a) => ReadS a
- readOct :: (Eq a, Num a) => ReadS a
- readHex :: (Eq a, Num a) => ReadS a
- readFloat :: RealFrac a => ReadS a
- lexDigits :: ReadS String
- fromRat :: RealFloat a => Rational -> a
- class Fractional a => Floating a where
  - pi :: a
  - exp, log, sqrt :: a -> a
  - (**), logBase :: a -> a -> a
  - sin, cos, tan :: a -> a
  - asin, acos, atan :: a -> a
  - sinh, cosh, tanh :: a -> a
  - asinh, acosh, atanh :: a -> a
  - log1p :: a -> a
  - expm1 :: a -> a
  - log1pexp :: a -> a
  - log1mexp :: a -> a

# Showing

showSigned #

Arguments

:: Real a |
=> (a -> ShowS) | a function that can show unsigned values
-> Int | the precedence of the enclosing context
-> a | the value to show
-> ShowS |

Converts a possibly-negative `Real` value to a string.

showIntAtBase :: (Integral a, Show a) => a -> (Int -> Char) -> a -> ShowS #

Shows a non-negative `Integral` number using the base specified by the first argument, and the character representation specified by the second.

showInt :: Integral a => a -> ShowS #

Show non-negative `Integral` numbers in base 10.

showHex :: (Integral a, Show a) => a -> ShowS #

Show non-negative `Integral` numbers in base 16.

showOct :: (Integral a, Show a) => a -> ShowS #

Show non-negative `Integral` numbers in base 8.

showEFloat :: RealFloat a => Maybe Int -> a -> ShowS #

Show a signed `RealFloat` value using scientific (exponential) notation (e.g. `2.45e2`, `1.5e-3`).

In the call ``showEFloat` digs val`, if `digs` is `Nothing`, the value is shown to full precision; if `digs` is ``Just` d`, then at most `d` digits after the decimal point are shown.

showFFloat :: RealFloat a => Maybe Int -> a -> ShowS #

Show a signed `RealFloat` value using standard decimal notation (e.g. `245000`, `0.0015`).

In the call ``showFFloat` digs val`, if `digs` is `Nothing`, the value is shown to full precision; if `digs` is ``Just` d`, then at most `d` digits after the decimal point are shown.

showGFloat :: RealFloat a => Maybe Int -> a -> ShowS #

Show a signed `RealFloat` value using standard decimal notation for arguments whose absolute value lies between `0.1` and `9,999,999`, and scientific notation otherwise.

In the call ``showGFloat` digs val`, if `digs` is `Nothing`, the value is shown to full precision; if `digs` is ``Just` d`, then at most `d` digits after the decimal point are shown.

showFFloatAlt :: RealFloat a => Maybe Int -> a -> ShowS #

Show a signed `RealFloat` value using standard decimal notation (e.g. `245000`, `0.0015`).

This behaves as `showFFloat`, except that a decimal point is always guaranteed, even if not needed.

Since: base-4.7.0.0

showGFloatAlt :: RealFloat a => Maybe Int -> a -> ShowS #

Show a signed `RealFloat` value using standard decimal notation for arguments whose absolute value lies between `0.1` and `9,999,999`, and scientific notation otherwise.

This behaves as `showFFloat`, except that a decimal point is always guaranteed, even if not needed.

Since: base-4.7.0.0

showFloat :: RealFloat a => a -> ShowS #

Show a signed `RealFloat` value to full precision using standard decimal notation for arguments whose absolute value lies between `0.1` and `9,999,999`, and scientific notation otherwise.

showHFloat :: RealFloat a => a -> ShowS #

Show a floating-point value in the hexadecimal format, similar to the `%a` specifier in C's printf.

    >>> showHFloat (212.21 :: Double) ""
    "0x1.a86b851eb851fp7"
    >>> showHFloat (-12.76 :: Float) ""
    "-0x1.9851ecp3"
    >>> showHFloat (-0 :: Double) ""
    "-0x0p+0"

floatToDigits :: RealFloat a => Integer -> a -> ([Int], Int) #

`floatToDigits` takes a base and a non-negative `RealFloat` number, and returns a list of digits and an exponent. In particular, if `x>=0`, and

    floatToDigits base x = ([d1,d2,...,dn], e)

then

1.     n >= 1

2.     x = 0.d1d2...dn * (base**e)

3.     0 <= di <= base-1

# Reading

NB: `readInt` is the 'dual' of `showIntAtBase`, and `readDec` is the `dual' of `showInt`. The inconsistent naming is a historical accident.

readSigned :: Real a => ReadS a -> ReadS a #

Reads a signed `Real` value, given a reader for an unsigned value.

readInt #

Arguments

:: Num a |
=> a | the base
-> (Char -> Bool) | a predicate distinguishing valid digits in this base
-> (Char -> Int) | a function converting a valid digit character to an `Int`
-> ReadS a |

Reads an unsigned `Integral` value in an arbitrary base.

readDec :: (Eq a, Num a) => ReadS a #

Read an unsigned number in decimal notation.

    >>> readDec "0644"
    [(644,"")]

readOct :: (Eq a, Num a) => ReadS a #

Read an unsigned number in octal notation.

    >>> readOct "0644"
    [(420,"")]

readHex :: (Eq a, Num a) => ReadS a #

Read an unsigned number in hexadecimal notation. Both upper or lower case letters are allowed.

    >>> readHex "deadbeef"
    [(3735928559,"")]

readFloat :: RealFrac a => ReadS a #

Reads an unsigned `RealFrac` value, expressed in decimal scientific notation.

lexDigits :: ReadS String #

Reads a non-empty string of decimal digits.

# Miscellaneous

fromRat :: RealFloat a => Rational -> a #

Converts a `Rational` value into any type in class `RealFloat`.

class Fractional a => Floating a where #

Trigonometric and hyperbolic functions and related functions.

The Haskell Report defines no laws for `Floating`. However, '(+)', '(*)' and `exp` are customarily expected to define an exponential field and have the following properties:

- `exp (a + b)` = @exp a * exp b
- `exp (fromInteger 0)` = `fromInteger 1`

Minimal complete definition

pi, exp, log, sin, cos, asin, acos, atan, sinh, cosh, asinh, acosh, atanh

Methods

pi :: a #

exp :: a -> a #

log :: a -> a #

sqrt :: a -> a #

(**) :: a -> a -> a infixr 8 #

logBase :: a -> a -> a #

sin :: a -> a #

cos :: a -> a #

tan :: a -> a #

asin :: a -> a #

acos :: a -> a #

atan :: a -> a #

sinh :: a -> a #

cosh :: a -> a #

tanh :: a -> a #

asinh :: a -> a #

acosh :: a -> a #

atanh :: a -> a #

log1p :: a -> a #

``log1p` x` computes ``log` (1 + x)`, but provides more precise results for small (absolute) values of `x` if possible.

Since: base-4.9.0.0

expm1 :: a -> a #

``expm1` x` computes ``exp` x - 1`, but provides more precise results for small (absolute) values of `x` if possible.

Since: base-4.9.0.0

log1pexp :: a -> a #

``log1pexp` x` computes ``log` (1 + `exp` x)`, but provides more precise results if possible.

Examples:

- if `x` is a large negative number, ``log` (1 + `exp` x)` will be imprecise for the reasons given in `log1p`.
- if ``exp` x` is close to `-1`, ``log` (1 + `exp` x)` will be imprecise for the reasons given in `expm1`.

Since: base-4.9.0.0

log1mexp :: a -> a #

``log1mexp` x` computes ``log` (1 - `exp` x)`, but provides more precise results if possible.

Examples:

- if `x` is a large negative number, ``log` (1 - `exp` x)` will be imprecise for the reasons given in `log1p`.
- if ``exp` x` is close to `1`, ``log` (1 - `exp` x)` will be imprecise for the reasons given in `expm1`.

Since: base-4.9.0.0

Instances

Floating Double # | Since: base-2.1
Instance details Defined in GHC.Float Methods pi :: Double # exp :: Double -> Double # log :: Double -> Double # sqrt :: Double -> Double # (**) :: Double -> Double -> Double # logBase :: Double -> Double -> Double # sin :: Double -> Double # cos :: Double -> Double # tan :: Double -> Double # asin :: Double -> Double # acos :: Double -> Double # atan :: Double -> Double # sinh :: Double -> Double # cosh :: Double -> Double # tanh :: Double -> Double # asinh :: Double -> Double # acosh :: Double -> Double # atanh :: Double -> Double # log1p :: Double -> Double # expm1 :: Double -> Double # log1pexp :: Double -> Double # log1mexp :: Double -> Double #
Floating Float # | Since: base-2.1
Instance details Defined in GHC.Float Methods pi :: Float # exp :: Float -> Float # log :: Float -> Float # sqrt :: Float -> Float # (**) :: Float -> Float -> Float # logBase :: Float -> Float -> Float # sin :: Float -> Float # cos :: Float -> Float # tan :: Float -> Float # asin :: Float -> Float # acos :: Float -> Float # atan :: Float -> Float # sinh :: Float -> Float # cosh :: Float -> Float # tanh :: Float -> Float # asinh :: Float -> Float # acosh :: Float -> Float # atanh :: Float -> Float # log1p :: Float -> Float # expm1 :: Float -> Float # log1pexp :: Float -> Float # log1mexp :: Float -> Float #
Floating CDouble # |
Instance details Defined in Foreign.C.Types Methods pi :: CDouble # exp :: CDouble -> CDouble # log :: CDouble -> CDouble # sqrt :: CDouble -> CDouble # (**) :: CDouble -> CDouble -> CDouble # logBase :: CDouble -> CDouble -> CDouble # sin :: CDouble -> CDouble # cos :: CDouble -> CDouble # tan :: CDouble -> CDouble # asin :: CDouble -> CDouble # acos :: CDouble -> CDouble # atan :: CDouble -> CDouble # sinh :: CDouble -> CDouble # cosh :: CDouble -> CDouble # tanh :: CDouble -> CDouble # asinh :: CDouble -> CDouble # acosh :: CDouble -> CDouble # atanh :: CDouble -> CDouble # log1p :: CDouble -> CDouble # expm1 :: CDouble -> CDouble # log1pexp :: CDouble -> CDouble # log1mexp :: CDouble -> CDouble #
Floating CFloat # |
Instance details Defined in Foreign.C.Types Methods pi :: CFloat # exp :: CFloat -> CFloat # log :: CFloat -> CFloat # sqrt :: CFloat -> CFloat # (**) :: CFloat -> CFloat -> CFloat # logBase :: CFloat -> CFloat -> CFloat # sin :: CFloat -> CFloat # cos :: CFloat -> CFloat # tan :: CFloat -> CFloat # asin :: CFloat -> CFloat # acos :: CFloat -> CFloat # atan :: CFloat -> CFloat # sinh :: CFloat -> CFloat # cosh :: CFloat -> CFloat # tanh :: CFloat -> CFloat # asinh :: CFloat -> CFloat # acosh :: CFloat -> CFloat # atanh :: CFloat -> CFloat # log1p :: CFloat -> CFloat # expm1 :: CFloat -> CFloat # log1pexp :: CFloat -> CFloat # log1mexp :: CFloat -> CFloat #
Floating a => Floating (Identity a) # | Since: base-4.9.0.0
Instance details Defined in Data.Functor.Identity Methods pi :: Identity a # exp :: Identity a -> Identity a # log :: Identity a -> Identity a # sqrt :: Identity a -> Identity a # (**) :: Identity a -> Identity a -> Identity a # logBase :: Identity a -> Identity a -> Identity a # sin :: Identity a -> Identity a # cos :: Identity a -> Identity a # tan :: Identity a -> Identity a # asin :: Identity a -> Identity a # acos :: Identity a -> Identity a # atan :: Identity a -> Identity a # sinh :: Identity a -> Identity a # cosh :: Identity a -> Identity a # tanh :: Identity a -> Identity a # asinh :: Identity a -> Identity a # acosh :: Identity a -> Identity a # atanh :: Identity a -> Identity a # log1p :: Identity a -> Identity a # expm1 :: Identity a -> Identity a # log1pexp :: Identity a -> Identity a # log1mexp :: Identity a -> Identity a #
RealFloat a => Floating (Complex a) # | Since: base-2.1
Instance details Defined in Data.Complex Methods pi :: Complex a # exp :: Complex a -> Complex a # log :: Complex a -> Complex a # sqrt :: Complex a -> Complex a # (**) :: Complex a -> Complex a -> Complex a # logBase :: Complex a -> Complex a -> Complex a # sin :: Complex a -> Complex a # cos :: Complex a -> Complex a # tan :: Complex a -> Complex a # asin :: Complex a -> Complex a # acos :: Complex a -> Complex a # atan :: Complex a -> Complex a # sinh :: Complex a -> Complex a # cosh :: Complex a -> Complex a # tanh :: Complex a -> Complex a # asinh :: Complex a -> Complex a # acosh :: Complex a -> Complex a # atanh :: Complex a -> Complex a # log1p :: Complex a -> Complex a # expm1 :: Complex a -> Complex a # log1pexp :: Complex a -> Complex a # log1mexp :: Complex a -> Complex a #
Floating a => Floating (Op a b) # |
Instance details Defined in Data.Functor.Contravariant Methods pi :: Op a b # exp :: Op a b -> Op a b # log :: Op a b -> Op a b # sqrt :: Op a b -> Op a b # (**) :: Op a b -> Op a b -> Op a b # logBase :: Op a b -> Op a b -> Op a b # sin :: Op a b -> Op a b # cos :: Op a b -> Op a b # tan :: Op a b -> Op a b # asin :: Op a b -> Op a b # acos :: Op a b -> Op a b # atan :: Op a b -> Op a b # sinh :: Op a b -> Op a b # cosh :: Op a b -> Op a b # tanh :: Op a b -> Op a b # asinh :: Op a b -> Op a b # acosh :: Op a b -> Op a b # atanh :: Op a b -> Op a b # log1p :: Op a b -> Op a b # expm1 :: Op a b -> Op a b # log1pexp :: Op a b -> Op a b # log1mexp :: Op a b -> Op a b #
Floating a => Floating (Const a b) # | Since: base-4.9.0.0
Instance details Defined in Data.Functor.Const Methods pi :: Const a b # exp :: Const a b -> Const a b # log :: Const a b -> Const a b # sqrt :: Const a b -> Const a b # (**) :: Const a b -> Const a b -> Const a b # logBase :: Const a b -> Const a b -> Const a b # sin :: Const a b -> Const a b # cos :: Const a b -> Const a b # tan :: Const a b -> Const a b # asin :: Const a b -> Const a b # acos :: Const a b -> Const a b # atan :: Const a b -> Const a b # sinh :: Const a b -> Const a b # cosh :: Const a b -> Const a b # tanh :: Const a b -> Const a b # asinh :: Const a b -> Const a b # acosh :: Const a b -> Const a b # atanh :: Const a b -> Const a b # log1p :: Const a b -> Const a b # expm1 :: Const a b -> Const a b # log1pexp :: Const a b -> Const a b # log1mexp :: Const a b -> Const a b #