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Writing FITS

  Translation of MIDAS files to FITS format is done by the OUTTAPE command:

OUTTAPE cat[,list] device [flag] [dens,block] [type]

where the cat[,list] is a catalogue of files to be written with an optional list of numbers (see CREATE/xCAT for creation of catalogues). It can be defaulted by giving either ` *' or ` ?' in which case all files in catalogues set by the SET/xCAT command are written out. A single file can be written by specifying it with its full name including extension. The device may specify an actual tape device, a prefix for disk files or an explicit file name for a single file.

The flag is an optional list of three one-character flags specifying the append mode, the amount of information listed on the senior terminal and in the log file and if the LHCUTS descriptor in the file should be used for scaling (see help file for full description).

Note default options of the OUTTAPE command will start at the current tape position. This may over-write previous data on the tape. Be sure to use the append flag if files have to be added to the tape. Or position the tape at end-of-information using operating system utilities before writing new files.

The dens,block parameter can specify the tape density ( e.g. 1600 or 6250bpi) and a physical blocking factor in the range 1-10. By default, a blocking factor of 10 is used. Note that some old FITS readers may not be able to read blocked FITS files ( e.g. IHAP) in which case a blocking on 1 must be given explicitly. The tape density is used only for 9-track 1/2-inch tapes. Some 1/2-inch tape devices require the density also to be set manually on the drive.

The type flag is used to specify the type of FITS format to write where ` B' indicates basic FITS i.e. with integer format only. The default is ` O' for original including floating point representation.



next up previous contents index
Next: References Up: Conversion between FITS Previous: Reading FITS



Rein Warmels
Mon Jan 22 12:06:29 MET 1996