Lisp to automatically draw rectangles where it intersects with specific points

ron, i don't know why, but it gives error sometimes when i select a rectangle (even when not in a blocked layer) and it only prompts me to select one rectangle, but doesn't let me make another selection to count how many rectangles, equal to the one i previously selected, are in the slection set

... and it only prompts me to select one rectangle, but doesn't let me make another selection to count how many rectangles, equal to the one i previously selected, are in the slection set

Not sure I understand this statement.

The code worked in the sample drawing you posted.

i think that i'm the one who's not understanding your code then =(

i meant i need to select the rectangle and then make another selection to count how many equal rectangles are there

but your code only prompts me to select a rectangle and doesn't return me anything (which variable u assigned to give me a value?)

Try replacing:

(sssetfirst nil n)

with:

(if (= 0 (sslength n))
   (alert "Nothing in selection!")
   (progn (sssetfirst nil n) (alert (strcat (itoa (sslength n)) " objects in selection!")))
 )

thanks ron, now i'm understanding a little better what your code does

the variable n retrieves me the amount of objects

but your code is finding the rectangle in the whole drawing, i want to find the rectangle inside another selection set, is that possible?

Try this:

(defun c:foo (/ r o n s)
 (cond
   ((and (setq o (car (nentsel "\nPick your little rectangle: ")))
  (setq o (vlax-ename->vla-object o))
  (vlax-property-available-p o 'area)
  (setq r (vla-get-area o))
  (setq s (ssget '((0 . "*polyline"))))
  (setq n (ssadd))
    )
    (foreach b	(mapcar 'vlax-ename->vla-object (vl-remove-if 'listp (mapcar 'cadr (ssnamex s))))
      (cond ((and (vlax-property-available-p b 'area) (equal (vla-get-area b) r 1e-2))
      (ssadd (vlax-vla-object->ename b) n)
      (vl-catch-all-apply 'vla-put-color (list b 1))
     )
      )
    )
    (if (= 0 (sslength n))
      (alert "Nothing in selection!")
      (progn (sssetfirst nil n) (alert (strcat (itoa (sslength n)) " objects in selection!")))
    )
   )
 )
 (princ)
)
(vl-load-com)

excellent ron!

we're almost reaching a perfect resolution for my problem

your code is working smoothly

But just so u can understand better what i need, this part of your code is not needed:

(if (= 0 (sslength n))
      (alert "Nothing in selection!")
      (progn (sssetfirst nil n) (alert (strcat (itoa (sslength n)) " objects in selection!")))
    )

what i need is the value that the variable n is returning to me in your code!

but that's okay, i can remove this last part

Now, the last big deal:

i see that your using the 'area' property to find the same rectangles...

so is there a way to add some other property to refine that filter a bit, like rectangles with the same area AND same length?

or same maybe, same area AND same position in X or same position in Y?

Sorry .. this is the extent I'm willing to do for free. If you want to try and make changes , I'll help when I can ... but I have real work to do now.

ok ron, i understand, but thank you so much for your patience and contribution on the code, u have helped a lot

sorry if i bothered you