Module FITS

Description (classes)

Synopsis

This module is a bag of related fits classes and global functions.

The following functionality is available:

• Class FITSFieldCopier A FITSFieldCopier for copying Array RecordFields to FitsFields.
• Class AsciiTableExtension (ascii) TABLE extension.
• Class BinaryTable BinaryTable is used to translate a FITS binary table to an aips++ Table. BinaryTable inherits from the FITS BinaryTableExtension class and its primary use is to convert that class to an aips++ Table. The class starts with an already existing FitsInput object, which should be set at a BinaryTableExtension HDU. Member functions provide a TableDesc appropriate for the FITS data (to help in constructing an aips++ Table compatible with the BinaryTableExtension), a Table containing the current row of FITS data and a Table containing the next row of FITS data (which can be used to step through the FitsInput, copying each row using the RowCopier class), and a Table containin the entire FITS binary table from the current row to the end of the table.

  Motivation

  We need a way to get FITS data into aips++ Tables.
• Class BinaryTableExtension BINTABLE extension.
• Class BlockInput fixed-length blocked sequential input base class.
• Class BlockIO fixed-length blocked sequentual I/O base class. BlockIO is a low level base class that implements fixed-length blocked sequential I/O. Its derived classes, BlockInput and BlockOutput are used by the FitsInput and FitsOutput classes. Users will hardly ever need to use this class directly.
• Class BlockOutput fixed-length blocked sequential output base class.
• Class ConstFitsKeywordList list of read-only FITS keywords.
• Class CopyRecordToRecord Copies fields between Records, possibly to fields with another name.
• Class CopyRecordToTable Copies fields from a Record to columns of a Table. This class should be generalized, and made better. It is the analog of RowCopier, i.e. it copies all the fields from some Record to certain columns of a table. The mapping from fields to columns occurs at construction of the CopyRecordToTable object.

  Motivation

  This class should be generalized, and made better. It is the analog of RowCopier, i.e. it copies all the fields from some Record to certain columns of a table. The mapping from fields to columns occurs at construction of the CopyRecordToTable object.
• Class ExtensionHeaderDataUnit Base class for generalized exentensions HDU.
• Class FITS Static functions and enumerations. Many of the static functions are utility functions used internally in the implementation of the member functions of the FITS classes. They are placed in a single class to encapsulate them and to avoid adding many names to the global name space. More important, from the user's perspective, are the enumerations. They form the basic vocabulary of a FITS application. For example, instead of referring to the FITS NAXIS keyword, FITS::NAXIS should be used.
• Class FITSDateUtil A class with static functions to help deal with FITS dates This is a collection of static utility functions for creating and interpreting FITS date keywords (e.g. DATE-OBS). Its never necessary to construct a FITSDateUtil, just use the static functions to help handle FITS dates.

  Motivation

  The strings that make up the value of FITS dates have a precise format. This class encompasses knowlege of the formats used and hopefully simplifies their creation and conversion to and from aips++ MVTimes.
• Class FITSError Default FITS error handling function, typdef, and enumeration. FITSError contains the enumeration specifying the possible error message levels. It also contains the default error handling function for the FITS classes.

  Motivation

  Originally, FITS error message were simply sent to an ostream. In order to have these error messages go to the AIPS++ logger by default, this class was added. This was made a separate class because both BlockIo and FITS need to use this class. The anticipated replacements for the current FITS classes use a somewhat similar scheme.
• Class FITSFieldCopier Virtual base class for copying RORecordFields to FitsFields.
• Class FITSGroupWriter Simplified interface to create and write to FITS random groups. Like FITSTableWriter except that this must be the first HDU and all "columns" in the description must have the same type, i.e. float.
• Class FITSHistoryUtil A class with static functions to help deal with FITS History cards. This is a collection of static utility functions for use with FITS HISTORY keywords. Manipulate HISTORY information. FITS HISTORY cards are interconverted with String as follows:
  • 'HISTORY ' and trailing blanks are removed from each card.
  • Continuation cards are CARDS that have '>' in the first line.
  • A string is made by concatenating the leading card and all continuation cards.

  Motivation

  The FitsKeywordList class can be somewhat tedious to use, as it deals with, e.g., char* pointers rather than Strings. This class makes it easy to interconvert between the HISTORY keywords and a Vector of related history information.
• Class FITSKeywordUtil A class with static functions to help deal with FITS Keywords. This class provides functions to conveniently interconvert between AIPS++ types and a FitsKeywordList which is needed by the native FITS classes. It is more convenient to maintain the list within AIPS++ as a Record, so we only need methods to turn a FitsKeywordList into a Record, and vice versa. Note that it is not necessary to construct a FITSKeywordUtil object since you can use its static functions directly.

  Motivation

  The FitsKeywordList class can be somewhat tedious to use, as it deals with, e.g., char* pointers rather than Strings. This class makes it easy to interconvert between FITS keywords and AIPS++ types.
• Class FITSMultiTable View multiple FITS files as a single table. A FITSMultiTable is used to view a collection of FITS files on disk as a single Table. That is, when next() is called, when one Table ends the next is reopened until all files are exhausted. The FITS files must all have the same description. Something clever should be done about the keywords.
• Class FITSSpectralUtil A class with static functions to help deal with FITS spectral axes. This class provides functions to extract information from a FITS header about the spectral axis, to setup a FITS header with appropriate information for the spectral axis, and to translate to and from the MFrequency refrence frame codes and their FITS equivalents. It is never necessary to construct a FITSSpectralUtil, just use the static functions to help handle FITS Spectral axes.

  Motivation

  This is designed to be used after the keywords have been extracted from the FITS file using the FITSKeywordUtil class. Extracting spectral axis and related information requires detailed knowledge of FITS conventions that this class strives to encapsulize.
• Class FITSTable Attach a FITSTabular to a binary or ASCII table. FITSTable is a FITSTabular which is attached to a FITS table (on disk only presently), either Binary or ASCII.
• Class FITSTableWriter Simplified interface to create and write to a FITS Binary Table.
• Class FITSTabular Simplified interface to FITS tables with AIPS++ Look and Feel. FITSTablular is an obstract base class which is used for read-only access to tabular FITS-like data structures.
• Class FITSTimedTable FITSTimedTable is used to look at FITS tables which have a time column. In particular, it peeks ahead, and knows the time of the currentRow and of the nextRow. It is constructed with a pointer to any FITSTabular. Presently, no memory management is imposed to ensure that the pointer remains valid.
• Class FitsArray FITS array of given type.
• Class :description> FitsArray FITS array of FitsBit type.
• Class FitsBase Base class fore FitsField.
• Class FitsBit Helper class for FITS Binary Tables. This class is not intended for general use. It only has meaning in the context of FITS Binary tables. There its use is incorporated into the concept of a FitsField, where FitsBit is given a specialized interpretation.
• Class FitsDiskInput FITS input from disk.
• Class FitsDiskOutput FITS output to disk.
• Class FitsField Helper class.
• Class :description> FitsField Helper class.
• Class FitsFPUtil Utility functions for floating point values.
• Class FitsInput Fixed-length sequential blocked FITS input.
• Class FitsIO sequential FITS I/O. FitsIO is a base class that handles all the sequential blocked FITS I/O. Special derived classes do the input and output. No interpretation of the data is attempted here, there are special FITS classes that handle syntax and interpretation.
• Class FitsKeyCardTranslator Translator between Keyword lists and fixed FITS cars.
• Class FitsKeyword A FITS keyword contains a name, a value and a comment..
• Class FitsKeywordList Linked list of FITS keywords.
• Class FitsLogical FitsLogical is a helper class that is not intended for general use.
• Class FitsNameResult Analyse the name of a header card.
• Class FitsOutput Fixed-length sequential blocked FITS output.
• Class FitsParse Parse a header card.
• Class FitsStdInput FITS input from standard input.
• Class FitsStdOutput FITS output to standard output.
• Class FitsTape9Input FITS input from 9-track tape.
• Class FitsTape9Output FITS output to 9-track tape.
• Class FitsVADesc Variable Length Array Descriptor.
• Class FitsValueResult Analyse the value of a header card.
• Class HeaderDataUnit Base class that defines a HDU. The class HeaderDataUnit contains what is common to all header-data-units, including the collection of keywords. From this class a number of FITS header-data-units are derived, each of them with their own rich assortment of functions for accessing and manipulating data of specific types.
• Class ImageExtension IMAGE extension of given type.
• Class NoConvert FITS templated helper class. NoConvert is a template class that is not intended for general use, it is used internally.
• Class PrimaryArray Templated primary array base class of given type. A Primary Data Array is represented by the following:

  	      <Type> data_array [NAXIS1][NAXIS2]...[NAXISN]
  

  For a PrimaryArray, dims() gives the number of dimensions and dim(i) gives the value of the i-th dimension WARNING! Multi-dimensional arrays are stored in FORTRAN order, NOT in C order. Options on the store, copy, and move functions exist to convert from one order to the other, if that is necessary.

  It is important to understand the proper sequence of operations with respect to I/O and data access. For input, the `read()' functions allocate an internal buffer of the appropriate size, if not already allocated, as well as reading and converting data; a `read()' function must be performed prior to accessing the data, i. e. before executing any `()', `data()', `copy()', or `move()' function. For output, the `store()' function similarly allocates an internal buffer before transfering data, and must be executed prior to any data access or `write()' function. Note: If you call any version of store(), do not call set_next().

  Writing portions of an array at a time, rather than the entire array, is a special case. The `set_next()' function is provided for this purpose. It declares the intention to write out the next N elements and must be executed prior to any `data()' function. It allocates a buffer of appropriate size, if not already allocated. Again, via the `data()' functions, one accesses the array as if the entire array were in memory. The `write()' function always writes the number of current elements in the internal buffer. The sequence of operations for each portion of the array written would be:

  • `set_next(N)',
  • fill the array using `data(N)' or other `data()' functions
  • `write(fout)'.
  The `set_next()' function must NOT be used with `read()' or `store()' functions; unpredictable results will occur.
• Class PrimaryGroup Random Group datastructure.

  Please note that the NOST has deprecated the Random Group datastructure, it has been replaced by the much more powerfull BINTABLE extension.

• Class ReservedFitsKeyword Reserved FITS keyword.
• Class ReservedFitsKeywordCollection Collection of reserved FITS keywords.
• Class ScalarFITSFieldCopier A FITSFieldCopier for copying scalar non-string RecordFields to FitsFields.
• Class SDFITSTable SDFITSTable is derived from FITSTable. It contains additional checks and behaviour appropriate to the Single Dish FITS Convention hence this is a Single Dish FITS Table, or SDFITSTable. This class behaves much like FITSTable. It additionally verifies that the indicated HDU in the input FITS file follows the SDFITS convention (it has all of the required columns) and it treats keywords as virtual columns when appropriate. These virtual columns will appear as fields in the currentRecord and description and will NOT appear in the keywords.

  Motivation

  It was useful to encapsulate this behaviour in a class so that the checks on a valid SDFITS table and the treatment of keywords as virtual columns would not need to appear everywhere it might be used.
• Class StringFITSFieldCopier A FITSFieldCopier for copying String RecordFields to FitsFields.
• Class VariableArrayFITSFieldCopier Copy the current contents of the input RORecordFieldPtr to the output FitsField.

You may want to look at the individual header files to see whether you might not prefer to include only the header files you really need; it may be more efficient to do so.

Classes

ArrayFITSFieldCopier -- A FITSFieldCopier for copying Array RecordFields to FitsFields (full description)

AsciiTableExtension -- (ascii) TABLE extension (full description)

BinaryTable -- BinaryTable is used to translate a FITS binary table to an aips++ Table. (full description)

BinaryTableExtension -- BINTABLE extension (full description)

BlockIO -- fixed-length blocked sequentual I/O base class (full description)

BlockInput -- fixed-length blocked sequential input base class (full description)

BlockOutput -- fixed-length blocked sequential output base class (full description)

ConstFitsKeywordList -- list of read-only FITS keywords (full description)

CopyRecordToRecord -- Copies fields between Records, possibly to fields with another name. (full description)

CopyRecordToTable -- Copies fields from a Record to columns of a Table. (full description)

ExtensionHeaderDataUnit -- base class for generalized exentensions HDU (full description)

FITS -- static functions and enumerations (full description)

FITSDateUtil -- A class with static functions to help deal with FITS dates (full description)

FITSError -- default FITS error handling function, typdef, and enumeration (full description)

FITSFieldCopier -- Virtual base class for copying RORecordFields to FitsFields (full description)

FITSGroupWriter -- Simplified interface to create and write to FITS random groups (full description)

FITSHistoryUtil -- A class with static functions to help deal with FITS History cards. (full description)

FITSKeywordUtil -- A class with static functions to help deal with FITS Keywords. (full description)

FITSMultiTable -- View multiple FITS files as a single table (full description)

FITSSpectralUtil -- A class with static functions to help deal with FITS spectral axes. (full description)

FITSTable -- Attach a FITSTabular to a binary or ASCII table (full description)

FITSTableWriter -- Simplified interface to create and write to a FITS Binary Table (full description)

FITSTabular -- Simplified interface to FITS tables with AIPS++ Look and Feel. (full description)

FITSTimedTable -- (full description)

FitsArray -- FITS array of FitsBit type (full description)

FitsBase -- helper class ??? (full description)

FitsBit -- helper class for FITS Binary Tables (full description)

FitsDiskInput -- FITS input from disk (full description)

FitsDiskOutput -- FITS output to disk (full description)

FitsFPUtil -- Utility functions for floating point values (full description)

FitsField -- helper class ??? (full description)

FitsIO -- sequential FITS I/O (full description)

FitsInput -- fixed-length sequential blocked FITS input (full description)

FitsKeyCardTranslator -- translator between Keyword lists and fixed FITS cars (full description)

FitsKeyword -- FITS keyword (full description)

FitsKeywordList -- linked list of FITS keywords (full description)

FitsLogical -- FITS helper class (full description)

FitsNameResult -- analyse the name of a header card (full description)

FitsOutput -- fixed-length sequential blocked FITS output (full description)

FitsParse -- parse a header card (full description)

FitsStdInput -- FITS input from standard input (full description)

FitsStdOutput -- FITS output to standard output (full description)

FitsTape9Input -- FITS input from 9-track tape (full description)

FitsTape9Output -- FITS output to 9-track tape (full description)

FitsVADesc -- Variable Length Array Descriptor (full description)

FitsValueResult -- analyse the value of a header card (full description)

GBTACSTable -- A GBTBackendTable for the ACS (full description)

GBTAntennaFile -- GBTAntennaFile digests the FITS file holding GBT Antenna info (full description)

GBTBackendTable -- Attach a FITSTabular to a GBT backend FITS file (full description)

GBTDAPFile -- (full description)

GBTFITSBase -- A base class for GBT FITS files - primary keywords. (full description)

GBTGOFile -- GBTGOFile serves up the information from a GBT GO FITS file. (full description)

GBTLO1File -- Digests the LO1 FITS file. (full description)

GBTMultiACSTable -- A GBTMultiBackendTable for the ACS (full description)

GBTSampler -- (full description)

GBTScanLogReader -- (full description)

GBTStateTable -- Class for dealing with the STATE table in GBT FITS files. (full description)

HeaderDataUnit -- base class that defines a HDU (full description)

ImageExtension -- IMAGE extension of given type (full description)

NoConvert -- FITS templated helper class (full description)

OldGBTBackendTable -- Attach a FITSTabular to a GBT backend FITS file (full description)

OldGBTPositionTable -- Attach a FITSTabular to a binary or ASCII table (full description)

PrimaryArray -- templated primary array base class of given type (full description)

PrimaryGroup -- Random Group datastructure (full description)

ReadFITS -- read a FITS file from an AIPS++ array (full description)

ReadFITSin -- helper function for ReadFITS and WriteFITS (full description)

ReservedFitsKeyword -- reserved FITS keyword (full description)

ReservedFitsKeywordCollection -- collection of reserved FITS keywords (full description)

SDFITSTable -- SDFITSTable is a FITSTable which follows the Single Dish FITS Convention. (full description)

ScalarFITSFieldCopier -- A FITSFieldCopier for copying scalar non-string RecordFields to FitsFields (full description)

StringFITSFieldCopier -- A FITSFieldCopier for copying String RecordFields to FitsFields (full description)

VariableArrayFITSFieldCopier -- (full description)

WriteFITS -- write a FITS file to an AIPS++ array (full description)