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XRTSORT
This is a development version of XSORT which it will replace in time.
It includes some improvements to the user interface, but more
significantly allows arbitrarily shaped regions to be sorted, the
regions being input by ARD description. So it is now possible for the
user to sort an image, define a region interactively with Isys, then
feed that region back to xrtsort and extract a spectrum for that region.
The in-built shapes, ie circular, rectangular etc are now just special
cases where the ARD description is generated internally. All propagation
of region information is done via ARD decription.
To decide whether events fall within the specified region, a spatial
filter is created using the ARD description. Ideally this filter would
have a resolution equal to the instrument pixel size. However, for
reasons of size this is not possible. A coarser filter is therefore used
and the user has a choice of trading performance against precision via
the RES parameter. A value of 1 gives high resolution, low performance,
3 gives poorer resolution, and fastest performance. The default is 2.
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