.help imaddk Sep86 imfort
.ih
NAME
imaddk -- add a new keyword to an image header
.ih
SYNOPSIS
.nf
subroutine imaddk (im, keyw, dtype, comm, ier)

integer		im		#I image descriptor of open image
character*(*)	keyw		#I name of the new keyword
integer		dtype		#I keyword datatype code
character*(*)	comm		#I comment string describing keyword
integer		ier		#O status return
.fi
.ih
DESCRIPTION
The \fIimaddk\fR procedure is used to add a new keyword to the header of
an existing, open image.  The datatype of the new keyword must be specified
at creation time; the possible datatype codes for header keywords are given
in the following table.

.nf
	1	boolean (logical)
	2	character string
	3,4,5	short integer, don't-care integer, long integer
	6,7	real or double precision floating
.fi

A comment string may optionally be given to describ the keyword, i.e.,
its function or purpose.  The comment string is printed in image header
listings and is propagated onto FITS tapes.
.ih
RETURN VALUE
A zero status is returned if there is space for the new keyword, and the
keyword does not redefine an existing keyword.

.nf
SYS_IDBREDEF:	attempt to redefine an image header keyword
SYS_IDBOVFL:	out of space in image header
.fi
.ih
NOTES
The precision of a keyword name is currently limited to eight characters
(longer keyword names will be silently truncated), and all user defined
keyword names are rendered into upper case.  This is necessary to permit
use of the FITS image format to transport images.
An alternative to the relatively low level \fIimaddk\fR procedure is provided
by the \fIimakw\fR procedures, which will not add a new keyword if the named
keyword already exists, which also set the value of the new keyword, and which
avoid the need to use a datatype code.
.ih
SEE ALSO
imdelk, imacck, imakw
.endhelp