$<H1>$Help for 'extract' program.$</H1>$
$<PRE>$
Date help created:  28 Dec 1993
Date last updated:  09 Oct 1996
$</PRE>$
'extract' extracts chosen (hyper)planes from multi-dimensional
data files.  Thus extracting a three-dimensional volume from a
four-dimensional data file would involve the choosing a fixed
point in the one-dimensional rows orthogonal to the volume.

The input data file must be blocked.

To run the program type

	extract <extract script file>

The extract script file must have the following format:

	input <par file of input data file>
	output <output (extracted) data file>
	par <par file of output data file>	! this is optional
	extract <pairs of <dim. fixed>:<fixed point for this dim.>>
		! one pair for each fixed dimension

and a typical example would be

	input /usr/people/wb104/edl387/edl387_5.spc.par
	output /usr/people/wb104/edl387/edl387_5_224_136.spc
	extract 1:224 2:136
		! there are two fixed dims., dim. 1 and dim. 2
		! dim. 1 fixed at point 224
		! dim. 2 fixed at point 136

This fixes point 224 in dimension 1 and point 136 in dimension 2,
and extracts the data in the directions orthogonal to dims. 1 and 2.
If the original data set was 3-dimensional, the extracted data set
would be 1-dimensional.
