autolisp script, for counting objects with very similar areas

count_areas.lsp

(defun C:COUNTAREAS (/ areas roundedAreas counts)
	(setq areas (getAreas))
	(setq roundedAreas (roundListTo areas 0))
	(setq areaCounts (countItems roundedAreas))
	(formatCounts areaCounts)
)

(defun formatCounts (areaCounts / ac area count out)
	(setq out "")
	(foreach ac areaCounts
		(setq area (car ac))
		(setq count (cdr ac))
		(setq out (strcat out (rtos area) " x " (rtos count) ", "))
	)
	out
)

(defun getAreas (/ ssSelections objects areas)
	(setq ssSelections (ssget (list (cons 0 "*polyline, circle, ellipse"))))
	(setq objects (ssToVla ssSelections))
	(setq areas (mapcar '(lambda (x) (getArea x)) objects))
)

(defun ssToVla (ss / i l)
	(if ss
		(repeat (setq i (sslength ss))
			(setq l (cons (vlax-ename->vla-object (ssname ss (setq i (1- i)))) l))
		)
	)
)

(defun getArea (obj)
	(vla-get-area obj)
) 

(defun roundListTo(l decimalPlaces)
	(mapcar '(lambda (x) (roundTo x decimalPlaces)) l)
)

(defun roundto (value decimalPlaces)
	(roundm value (expt 10.0 (- decimalPlaces)))
)

(defun roundm (n m)
	(* m (fix ((if (minusp n) - +) (/ n (float m)) 0.5)))
)

(defun countItems ( list / pair out)
	(reverse
		(foreach i list
			(setq out
				(if (setq pair (assoc i out))
					(subst (cons i (1+ (cdr pair))) pair out)
					(cons (cons i 1) out)
				)
			)
		)
	)
)