Data.Fits

Definitions for the data types needed to parse an HDU in a FITS block.

Data payload functions

parsePix :: Int -> BitPixFormat -> ByteString -> IO [Pix]

This is the main low-level function which parses the data portion of an HDU. You need and element count, a format and a bytestring. The resulting list is produced in column-row major order as specified in the standard.

pixsUnwrapI :: BitPixFormat -> [Pix] -> [Int]

Remove the Pix wrapper for integer Pix lists.

pixsUnwrapD :: BitPixFormat -> [Pix] -> [Double]

Remove the Pix wrapper for floating point Pix lists.

Main data types

data HeaderDataUnit

The HeaderDataUnit is the full HDU. Both the header information is encoded alongside the data payload.

Constructors

HeaderDataUnit

Fields

• _header :: Header

  The heeader contains metadata about the payload

• _dimensions :: Dimensions

  This dimensions of the main data array

• _extension :: Extension

  Extensions may vary the data format

• _mainData :: ByteString

  The main data array

Instances

Show HeaderDataUnit

Defined in Data.Fits

Methods

showsPrec :: Int -> HeaderDataUnit -> ShowS

show :: HeaderDataUnit -> String

showList :: [HeaderDataUnit] -> ShowS

dimensions :: Lens' HeaderDataUnit Dimensions

header :: Lens' HeaderDataUnit Header

extension :: Lens' HeaderDataUnit Extension

mainData :: Lens' HeaderDataUnit ByteString

data Pix

Following BitPixFormat we have a tag for integer and floating point values. We box them up to ease parsing.

Constructors

PB Int

PI16 Int

PI32 Int

PI64 Int

PF Double

PD Double

Header Data Types

newtype Header

The header part of the HDU is vital carrying not only authorship metadata, but also specifying how to make sense of the binary payload that starts 2,880 bytes after the start of the HeaderData.

Constructors

Header

Fields

• _records :: [HeaderRecord]

Instances

Monoid Header

Defined in Data.Fits

Methods

mempty :: Header

mappend :: Header -> Header -> Header

mconcat :: [Header] -> Header

Semigroup Header

Defined in Data.Fits

Methods

(<>) :: Header -> Header -> Header

sconcat :: NonEmpty Header -> Header

stimes :: Integral b => b -> Header -> Header

Show Header

Defined in Data.Fits

Methods

showsPrec :: Int -> Header -> ShowS

show :: Header -> String

showList :: [Header] -> ShowS

Eq Header

Defined in Data.Fits

Methods

(==) :: Header -> Header -> Bool

(/=) :: Header -> Header -> Bool

keywords :: SimpleGetter Header [KeywordRecord]

Return all KeywordRecords from the header, filtering out full-line comments and blanks

records :: Lens' Header [HeaderRecord]

data HeaderRecord

Headers contain lines that are any of the following

KEYWORD = VALUE / inline comment
COMMENT full line comment
(blank)

Constructors

Keyword KeywordRecord

Comment Text

BlankLine

Instances

Show HeaderRecord

Defined in Data.Fits

Methods

showsPrec :: Int -> HeaderRecord -> ShowS

show :: HeaderRecord -> String

showList :: [HeaderRecord] -> ShowS

Eq HeaderRecord

Defined in Data.Fits

Methods

(==) :: HeaderRecord -> HeaderRecord -> Bool

(/=) :: HeaderRecord -> HeaderRecord -> Bool

data KeywordRecord

A single 80 character header keyword line of the form: KEYWORD = VALUE / comment KEYWORD=VALUE

Constructors

KeywordRecord

Fields

• _keyword :: Text
• _value :: Value
• _comment :: Maybe Text

Instances

Show KeywordRecord

Defined in Data.Fits

Methods

showsPrec :: Int -> KeywordRecord -> ShowS

show :: KeywordRecord -> String

showList :: [KeywordRecord] -> ShowS

Eq KeywordRecord

Defined in Data.Fits

Methods

(==) :: KeywordRecord -> KeywordRecord -> Bool

(/=) :: KeywordRecord -> KeywordRecord -> Bool

data Extension

Constructors

Primary

Any header data unit can use the primary format. The first MUST be Primary. This is equivalent to having no extension

Image

An encoded image. PCOUNT and GCOUNT are required but irrelevant

BinTable

A Binary table. PCOUNT is the number of bytes that follow the data in the heap

Fields

• pCount :: Int
• heap :: ByteString

Instances

Show Extension

Defined in Data.Fits

Methods

showsPrec :: Int -> Extension -> ShowS

show :: Extension -> String

showList :: [Extension] -> ShowS

Eq Extension

Defined in Data.Fits

Methods

(==) :: Extension -> Extension -> Bool

(/=) :: Extension -> Extension -> Bool

getKeywords :: Header -> [KeywordRecord]

Return all KeywordRecords from the header, filtering out full-line comments and blanks

lookup :: Text -> Header -> Maybe Value

isKeyword :: Text -> KeywordRecord -> Bool

data Value

Value datatype for discriminating valid FITS KEYWORD=VALUE types in an HDU.

Constructors

Integer Int

Float Float

String Text

Logic LogicalConstant

Instances

Show Value

Defined in Data.Fits

Methods

showsPrec :: Int -> Value -> ShowS

show :: Value -> String

showList :: [Value] -> ShowS

Eq Value

Defined in Data.Fits

Methods

(==) :: Value -> Value -> Bool

(/=) :: Value -> Value -> Bool

toInt :: Value -> Maybe Int

toFloat :: Value -> Maybe Float

toText :: Value -> Maybe Text

data LogicalConstant

Direct encoding of a Bool for parsing Value

Constructors

T

F

Instances

Show LogicalConstant

Defined in Data.Fits

Methods

showsPrec :: Int -> LogicalConstant -> ShowS

show :: LogicalConstant -> String

showList :: [LogicalConstant] -> ShowS

Eq LogicalConstant

Defined in Data.Fits

Methods

(==) :: LogicalConstant -> LogicalConstant -> Bool

(/=) :: LogicalConstant -> LogicalConstant -> Bool

data Dimensions

When we load a header, we parse the BITPIX and NAXIS(N) keywords so we - can know how long the data array is

Constructors

Dimensions

Fields

• _bitpix :: BitPixFormat
• _axes :: Axes

Instances

Show Dimensions

Defined in Data.Fits

Methods

showsPrec :: Int -> Dimensions -> ShowS

show :: Dimensions -> String

showList :: [Dimensions] -> ShowS

Eq Dimensions

Defined in Data.Fits

Methods

(==) :: Dimensions -> Dimensions -> Bool

(/=) :: Dimensions -> Dimensions -> Bool

axes :: Lens' Dimensions Axes

bitpix :: Lens' Dimensions BitPixFormat

data SimpleFormat

The standard defines two possible values for the SIMPLE keyword, T and F. The T refers to a Conformant format while F refers to a NonConformant format. At this time only the Conformant, T, format is supported.

Constructors

Conformant

NonConformant

Instances

Show SimpleFormat

Value of SIMPLE=T in the header. supported NonConformat ^ Value of SIMPLE=F in the header. unsupporteddata/fi

Defined in Data.Fits

Methods

showsPrec :: Int -> SimpleFormat -> ShowS

show :: SimpleFormat -> String

showList :: [SimpleFormat] -> ShowS

Eq SimpleFormat

Defined in Data.Fits

Methods

(==) :: SimpleFormat -> SimpleFormat -> Bool

(/=) :: SimpleFormat -> SimpleFormat -> Bool

data BitPixFormat

The BitPixFormat is the nitty gritty of how the Axis data is layed out in the file. The standard recognizes six formats: unsigned 8 bit integer, two's complement binary integers at 16, 32, and 64 bits along with 32 and 64 bit IEEE floating point formats.

Constructors

EightBitInt

BITPIX = 8; unsigned binary integer of 8 bits

SixteenBitInt

BITPIX = 16; two's complement binary integer of 16 bits

ThirtyTwoBitInt

BITPIX = 32; two's complement binary integer of 32 bits

SixtyFourBitInt

BITPIX = 64; two's complement binary integer of 64 bits

ThirtyTwoBitFloat

BITPIX = -32; IEEE single precision floating point of 32 bits

SixtyFourBitFloat

BITPIX = -64; IEEE double precision floating point of 64 bits

Instances

Show BitPixFormat

Defined in Data.Fits

Methods

showsPrec :: Int -> BitPixFormat -> ShowS

show :: BitPixFormat -> String

showList :: [BitPixFormat] -> ShowS

Eq BitPixFormat

Defined in Data.Fits

Methods

(==) :: BitPixFormat -> BitPixFormat -> Bool

(/=) :: BitPixFormat -> BitPixFormat -> Bool

type Axes = [Int]

Axes represents the combination of NAXIS + NAXISn. The spec supports up to 999 axes

Utility

isBitPixInt :: BitPixFormat -> Bool

This utility functions quickly lets you know if you are dealing with integer data.

isBitPixFloat :: BitPixFormat -> Bool

This utility functions quickly lets you know if you are dealing with floating point data.

bitPixToWordSize :: BitPixFormat -> Int

This utility function can be used to get the word count for data in an HDU.

bitPixToByteSize :: BitPixFormat -> Int

This utility function can be used to get the size in bytes of the - format.

pixDimsByCol :: Axes -> [Int]

pixDimsByRow :: Axes -> [Int]

Constants

hduRecordLength :: Int

A single record in the HDU is an eighty byte word.

hduMaxRecords :: Int

The maximum amount of eighty byte records is thirty-six per the standard.

hduBlockSize :: Int

The size of an HDU block is fixed at thirty-six eighty byte words. In other words 2,880 bytes. These blocks are padded with zeros to this boundary.