Subject: FITSIO Version 3

From: pence at heawk1.gsfc.nasa.gov ( William Pence)
Date: 23 Sep 91 21:15:24 GMT

FITSIO - Version 3.00

This is to announce that Version 3 of the FITSIO package is now available
for general use.  FITSIO is a Fortran-77 subroutine interface for reading
and writing files in the FITS (Flexible Image Transport System) format.
This new version of FITSIO has been completely rewritten and offers many
additional capabilities and enhancements not found in the previous
version, including:

  - direct access I/O which allows the data in the FITS file to be read or
  written in any random order.  The previous version of FITSIO had required
  that all the bytes of data in the file be accessed in strict sequential
  order.  

  - implicit datatype conversion. This allows users to read (or write) data
  from a FITS array or table column of a given datatype (e.g. short
  integers) into a different datatype array (e.g. Real*4).  

  - automatic data scaling can be performed (using the BZERO and BSCALE, or
  TZEROnnn and TSCALnnn values).

  - access to data in ASCII and Binary table extensions is now much more 
  convenient.  In general, the interface reads or writes individual columns 
  of data in a table with a single subroutine call.

  - a more logical and consistent calling parameter sequence is used
  throughout all the subroutines in the interface.  Unfortunately, this
  also means that the calling sequences in Version 3 are entirely
  different from those in Version 2.  Any future versions, if any,
  will be designed to be upwardly compatible with Version 3.

As with the previous version, this new FITSIO package is strictly
oriented towards access to FITS files on magnetic disk, not magnetic
tape.  Support for tape devices might be added later, but this may be
difficult due to the random access capabilities which are fundamental
to this implementation.  (Programmers interested in modify this package
to support mag tapes should probably start with FITSIO Version 2, since
it accesses the FITS file in a purely sequential order).

About 95% of the FITSIO code is written in strict Fortran-77.  A small
set of subroutines specific to a particular machine are also provided
(VAX/VMS, DECstations, SUN workstations, and IBM PCs are currently
supported with an IBM mainframe version due in a couple weeks).  For
programmers preferring a C language implementation, these Fortran
subroutines can be processed through the public domain 'f2c' conversion
program.  We have only done limited testing of this, but it appeared that
the C version of the code runs and produces the same FITS file output as
the Fortran version. 

Because this is a new release of a large set of code, it is likely
that some bugs still remain.  Please send any problem reports to me
at:   pence at tetra.gsfc.nasa.gov or to LHEAVX::PENCE.  Users should also
periodically check to see if a new release has been made.  (The file
called 'version.nnn' in the release directory indicates the current
release version.  The current release is 'version.300'.)

This version conforms to the FITS file formats defined in the draft
standard published by the NASA/OSSA Office of Standards and Technology
(NOST) and in the draft 'Binary Table Extensions to FITS' dated 20 May
1991.  The only significant feature not supported in the current version
of FITSIO is the 'Variable Length Array' facility in binary tables.
Support for this will be added in the near future.  A new version of
FITSIO will be issued whenever the above documents are revised.

To get a copy of the FITSIO software and documentation, use anonymous
ftp to connect to:

       ftp tetra.gsfc.nasa.gov
                or
       ftp 128.183.8.77

Then type the following:

        ftp>  user anonymous
        Password:               [type your username as a password]
        ftp>  cd pub/fitsio3    [to move to the version 3 subdirectory]
        ftp>  ls                [to see a list of the available files]
        ftp>  get read.me       [contains latest information about FITSIO]
        ftp>  get fitsio.doc    [complete user documentation]
        ftp>  get ...           [get any additional desired files]
        ftp>  exit

Alternatively, the FITSIO files may be copied from following SPAN node

   NDADSA::HEASARC:[EXOSAT.XANADU.FITSIO.VERSION3] 

William Pence
HEASARC
Code 668
NASA/Goddard Space Flight Center
Greenbelt, MD 20771