is something like this an acceptable approach?  (just teat a linear array like a 2d array).  seems like a better version of this stuff is probably part of the included stuff, I would imagine.  Like there's probably a way to get the size of a vector.  I was going to make a (array-2d-print) function, too that displays it like a grid ..... maybe tomorrow.  Any suggested improvements or directions are of course welcome. (define (make-array-2d size initial)   (make-vector (* size size) initial)) (define (array-2d-ref array size row col)   (vector-ref array (+ (* row size) col))) (define (array-2d-set! array size row col value)   (vector-set! array (+ (* row size) col))) > (define deposits (make-array-2d 17 0)) > (array-2d-ref deposits 17 0 11) 0 > (array-2d-set! deposits 17 0 11 39) > (array-2d-ref deposits 17 0 11) 39 <div class="gmail_quote">On Sat, Feb 14, 2009 at 4:40 PM, Chongkai Zhu <<a href="mailto:czhu@cs.utah.edu">czhu@cs.utah.edu</a>> wrote: <blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> and every slot of the vector is filled with `fill'. In your</blockquote></div>