(update-cell) accounts for perimeter neighbors.

practice/aa.scm

@@ -86,18 +86,6 @@ MASTER-SCHEDULER(T+1)
  (neighbor-a nba nba!) (neighbor-b nbb nbb!) (neighbor-c nbc nbc!)
 )
 
-;;don't develop rlem object unless rlem record proves insufficient
-#;(define (rlem-3453 id mem ai bi ci ao bo co na nb nc)
- (define state (rlem-3453-state id mem ai bi ci ao bo co na nb nc))
-
- (define (self msg)
- (case (car msg)
- ['state state]
- )
- )
- self
-)
-
 (define (rlem-3453-lattice r c . cl-list)
  (define cell-list (if (null? cl-list) (rlem-hex-grid r c) (car cl-list)))
  (define activation-order (map id (random-permutation (cdr cell-list))))
@@ -118,25 +106,31 @@ MASTER-SCHEDULER(T+1)
  (let* ([cell (cell-list-ref index)] 
  [in (lambda () (list (ai cell) (bi cell) (ci cell)))] ;lazy in
  [out (list (ao cell) (bo cell) (co cell))] 
- [nba (cell-list-ref (nba cell))] 
- [nbb (cell-list-ref (nbb cell))]
- [nbc (cell-list-ref (nbc cell))]
+ [nbra (cell-list-ref (nba cell))] 
+ [nbrb (cell-list-ref (nbb cell))]
+ [nbrc (cell-list-ref (nbc cell))]
  [empty? (lambda (c) (equal? '(0 0 0) c))]
  [inhale ;gather new input from neighbors' outputs
  (lambda () 
  (begin
- (ai! cell (ao nba)) (bi! cell (bo nbb)) (ci! cell (co nbc))
- (ao! nba 0) (bo! nbb 0) (co! nbc 0)))] ;clear nbr outputs
+ (ai! cell (ao nbra)) (bi! cell (bo nbrb)) (ci! cell (co nbrc))
+ (ao! nbra 0) (bo! nbrb 0) (co! nbrc 0)))] ;clear nbr outputs
  [process 
  (lambda ()
  (if (not (empty? (in))) ;did (inhale) acquire new input?
  (begin
- (case (mem cell) ;rotate in right/left, write to out
+ (case (mem cell) ;rotate input right/left, write to output
  ['0 (ao! cell (ci cell)) (bo! cell (ai cell)) ;right
  (co! cell (bi cell))]
  ['1 (ao! cell (bi cell)) (bo! cell (ci cell)) ;left
  (co! cell (ai cell))])
  (ai! cell 0) (bi! cell 0) (ci! cell 0) ;clear inputs
+ (if (equal? (nba cell) 'p) 
+ (ao! cell 0)) ;}if cell borders the perimeter
+ (if (equal? (nbb cell) 'p) ;}immediately dispose of its
+ (bo! cell 0)) ;}output channel values
+ (if (equal? (nbc cell) 'p) 
+ (co! cell 0))
  (mem! cell (abs (- (mem cell) 1))))))]) ;mem switch
  (cond
  [(and (empty? out) (empty? (in))) (begin (inhale) (process))]
@@ -169,7 +163,47 @@ MASTER-SCHEDULER(T+1)
  self
 )
 
-;;f(rows, cols) => neighbor-list, neighbor-list:={(Id,nba,nbb,nbc)...}
+#|
+An example 3x5 hex grid constructed by (rlem-hex-grid), overlaid on a
+rectangular co-ordinate graph. The first element of the first row, indexed as 
+id-0, is at hex-co-ordinate x(0,0), equivalent to ortho-co-ordinate r(2,2) on
+this graph due to a 2-up, 2-right translation. Element id-1 is at x(0,1) or 
+r(3,3). Elements id-0 through id-5, id-6 through id-B, and id-C through
+id-H comprise rows 1, 2, and 3, respectively. Column 1 is composed of
+elements id-0, id-6, and id-C, and so forth for the others. Rows grow up and to
+the right (alternatively from south-west to north-east); with respect to Row 1,
+subsequent rows can be generated by a 1-up translation. "p" indicates the
+special perimeter cell, which does not update state, always sources "0" on its
+output channels, and immediately sinks its neighbors non-zero output channel 
+values so that they do not block.
+
+ y
+ |
+ A p 
+ | \ 
+ 9 p H-p
+ | \ /
+ 8 p F-G
+ | \ / \
+ 7 D-E B-p
+ | / \ /
+ 6 p-C 9-A
+ | \ / \ 
+ 5 7-8 5-p
+ | / \ /
+ 4 p-6 3-4
+ | \ / \
+ 3 1-2 p
+ | / \
+ 2 p-0 p 
+ | \
+ 1 p
+ | 
+--o-1-2-3-4-5-6-7-8-9-x
+ |
+ |
+|#
+;;f(rows, cols) => cell-list
 (define (rlem-hex-grid rows cols)
  (let* ([size (* rows cols)]
  [p (rlem-3453-state 'p 0 0 0 0 0 0 0 '_ '_ '_)]
@@ -247,16 +281,16 @@ MASTER-SCHEDULER(T+1)
 
 (define (step lat . t)
  (dispnl* (cons 'original-lattice-state (lat '(cell-list))))
- (cond
-  [(null? t) (step lat 1)]
- [(equal? (car t) 1) (begin 
-  (lat '(update-lattice 1))
-  (dispnl* (cons `(steps-to-go ,(car t)) 
-  (lat '(cell-list)))))]
- [else (begin 
- (lat '(update-lattice 1))
- (dispnl* (cons `(steps-to-go ,(car t)) (lat '(cell-list))))
-  (step lat (- (car t) 1)))]))
+ (let next ([ts (if (null? t) 1 (car t))])
+  (cond
+   [(equal? ts 1) (begin 
+ (lat '(update-lattice 1))
+ (dispnl* (cons `(steps-to-go ,ts) 
+  (lat '(cell-list)))))]
+   [else (begin 
+   (lat '(update-lattice 1))
+   (dispnl* (cons `(steps-to-go ,ts) (lat '(cell-list))))
+  (next (- ts 1)))])))
 
 (define tstrlem0 (rlem-3453-state 'tst 0 0 0 0 0 0 0 0 0 0))
 (define tstgrid0 (rlem-hex-grid 5 4))
@@ -281,4 +315,7 @@ MASTER-SCHEDULER(T+1)
  (dispnl* (cons 'randlat0-cell-list-new-born (randlat0 '(cell-list))))
  (dispnl* (cons 'randlat0-update-lattice-5 (randlat0 '(update-lattice 5))))
  (dispnl* (cons 'randlat0-cell-post-update-lattice-5 (randlat0 '(cell-list))))
+ ;show the work
+ (dispnl* 'step-through-random-10x10-lattice-10-times)
+ (step (random-lattice 10 10) 10)
 )