%N boxrect %F $MIR/src/subs/boxes.for
%D Determine if a region-of-interest is rectangular.
%P mjs
%: region-of-interest
%B
      logical function BoxRect(boxes)

      integer boxes(*)
  ---------------------------------------------------------------------
  This returns .true. if the region described by the boxes array is
  purely rectangular (i.e. describable by blc and trc).

  Input:
    boxes      Integer array describing intermediate form of the region
               selected.
  Output:
    BoxRect    True if the region is rectangular.
