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Writing header items

This example (taken from a complete program hdrwrite.f - see §[*]) shows how to write the value of a header item to an image associated with the parameter 'OUT':
*  Write the new header item.
      CALL HDR_OUT( 'OUT', ' ', 'OBSERVER', 'The observer',   [1]
     :              'Fred Bloggs', ISTAT )

*  Free the image.
      CALL IMG_FREE( 'OUT', ISTAT )                           [2]
The following notes refer to the numbered statements:
1.
The call to HDR_OUT specifies the image by using its parameter name - 'OUT' (argument 1). If you have not previously accessed this image you will probably be prompted for its file name at this point. If you have already accessed the image then it should be either an output image or one accessed for modification, as you cannot write items to images accessed by IMG_IN.

The 2nd, blank argument, indicates that an ``ordinary'' FITS header item is to be written.

The 3rd argument ('OBSERVER') specifies the name of the header item and the 4th argument 'The observer' is a comment to store with the item.

The 5th argument ('Fred Bloggs') is the header item value.

2.
The image is freed. If this wasn't done, the new header item would be lost.



next up previous 231
Next: ADDITIONAL FEATURES
Up: ACCESSING HEADER INFORMATION
Previous: Reading header items

IMG Simple Image Data Access
Starlink User Note 160
P.W. Draper
R.F. Warren-Smith
3 March 2003
E-mail:P.W.Draper@durham.ac.uk

Copyright © 2000-2003 Council for the Central Laboratory of the Research Councils