


                                  - 1 -



       COMMAND

       llllggggttttwwwwiiiisssstttt,,,, llllttttttttwwwwiiiisssstttt ---- ttttwwwwiiiisssstttt ddddaaaattttaaaa bbbbyyyy pppprrrrooooppppoooorrrrttttiiiioooonnnnaaaallll sssshhhhiiiiffffttttiiiinnnngggg

       USAGE

       llllggggttttwwwwiiiisssstttt [----llll|rrrr]

       llllttttttttwwwwiiiisssstttt [----uuuu|dddd]

       DESCRIPTION

       The llllggggttttwwwwiiiisssstttt and llllttttttttwwwwiiiisssstttt commands operate upon the data for
       the current image in a very similar manner but produce quite
       different results.  Both commands result in the shifting of
       each radius of a given initial longitudinal profile or
       latitudinal slice to a new position which is displaced by a
       shift proportional to its separation from the lower latitude
       limit or from the lower longitude limit respectively.

       ----llll    Shift data left (+) by (_l_t-_l_t_m_i_n) positions.

       ----rrrr    Shift data right (-) by (_l_t-_l_t_m_i_n) positions.

       ----uuuu    Shift data up (+) by (lg-lgmin) positions.

       ----dddd    Shift data down (-) by (lg-lgmin) positions.

       The sense of the shifts in the data and the apparent twist
       is reckoned from the point of view of an outside observer.
       Accordingly, the features nearer the upper latitude limit of
       an llllggggttttwwwwiiiisssstttt-ed image will appear to be twisted lllleft or rrrright.
       Similarly, the features nearer the upper longitude limit of
       an llllttttttttwwwwiiiisssstttt-ed image will appear to be twisted uuuupward or
       ddddownward.

       Both llllggggttttwwwwiiiisssstttt and llllttttttttwwwwiiiisssstttt operate only within the current
       latitude/longitude range window.  Accordingly, wrap around
       occurs at whatever boundaries you have currently set.  The
       llllggggttttwwwwiiiisssstttt command with fully expanded longitude range produces
       the most easily oriented effect upon the image even when
       applied many times since its effect is severe twisting free
       of incisions.  Virtually every other instance of lgtwisted
       or lttwisted images possess discontinuities along a diagonal
       of the current range window.  That discontinuity separates
       simply-twisted data from twisted data which has been
       displaced by one range width or height due to wrap around.

       The commands are often used with rrrreeeeppppeeeeaaaatttt to achieve multiple
       twists.












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       These commands are in place primarily for the purpose of
       creating artistic or otherwise interesting effects but they
       have also been useful in a few practical problem solving
       situations.

       CAVEATS

       Remember that the shifts occur only within the current lt/lg
       range window with wrap around at the the bounding longitudes
       of the window.

       Use of these commands in conjunction with others available
       to you could raise havoc with your spare time.














































