############################################################################
#
#	File:     dd2unit.icn
#
#	Subject:  Program to get dimensions of unit motif of pattern
#
#	Author:   Ralph E. Griswold
#
#	Date:     June 12, 2002
#
############################################################################
#
#  This file is in the public domain.
#
############################################################################
#
#  The following command line option is supported:
#
#	-p	assume partial repeats may occur at edges of pattern;
#		default complete repeats 
#
############################################################################
#
#  Links:  options, patutils, seqops
#
############################################################################

link options
link patutils
link seqops

global switch

procedure main(args)
   local rows, opts

   opts := options(args, "p")
   switch := opts["p"]

   rows := unit(pat2rows(read()))
   write(*rows[1], "x", *rows)

end

procedure rot90(rows)		# rotate pattern 90 degrees clockwise
   local columns, i, j

   columns := list(*rows[1], "")

   every i := 1 to *rows do
      every j := 1 to *columns do
         columns[j] ||:= rows[i][j]

   return columns

end

procedure unit(grid)

   grid := grepeat(grid)

   grid := grepeat(rot90(grid))

   return rot90(grid)

end

procedure grepeat(grid)		#: reduce grid to smallest repeat
   local periods, i, width

   grid := copy(grid)

   periods := []

   width := *grid[1]

   every i := 1 to *grid do
      put(periods, speriod(str2lst(grid[i]), switch) | width)

   width >:= lcml ! periods

   every i := 1 to *grid do
      grid[i] := left(grid[i], width)

   return grid

end