Area in metric from English units drawing

[robert.1.hall72202]

I need a lisp routine that:

Selects an object (polyline, hatch, etc.)
that is drawn in english untis

and

Returns the area in metric units mm^2


Anybody know how to do this?

[Jeff_M]

You can supply the selection & area portions, this will convert the area to mm^2:

(cvunit 60.0 "feet^2" "mm^2")
(cvunit 60.0 "inch^2" "mm^2")

[.T.]

Here is a quick and dirty that should work for hatch or polyline entities for getting the raw area, but I didn't try it on lines, arcs, etc.:

(defun c:getarea (/ e vlaobj)
   (setq e (entget (car (entsel))))
   (setq vlaobj (vlax-ename->vla-object (dxf -1 e)))
   (vlax-get-property vlaobj 'Area)
);defun

It should at least get you started.

Take care,
Tim

[robert.1.hall72202]

Ok, that is giving me:

Select object: ; error: no function definition: DXF

[Opie]

Ok, that is giving me:

Select object: ; error: no function definition: DXF

Robert,

Try this function. It appears Tim has a routine to extract some data from an entity's group code data.

(defun DXF (ELEMENT ENTITY /) (cdr (assoc ELEMENT ENTITY))) ;;; retrieve assoc data from entity

Tim, If the above code is not right, please let Robert know. Just trying to help out.

[robert.1.hall72202]

that solves the dxf error

however............

; error: ActiveX Server returned the error: unknown name: AREA

[Opie]

that solves the dxf error

however............

; error: ActiveX Server returned the error: unknown name: AREA

I can't fix everything.

I'll see what I can come up with after lunch, if I have time.

[Opie]

Just a quick thought. Have you tried adding (vl-load-com) to the beginning of the routine?

[.T.]

Oops, sorry,

In my haste, I forgot to give you the dxf function:

(defun dxf (code elist)
(cdr (assoc code elist))
);defun

Also, it looks like it only returns the area for those items that have area (i.e. hatch and polylines).

I hope this helps.

By the way, from personal experience, it is possible to golf in the snow. It's pretty frustrating when the ball turns into a snowball and won't fit in the hole, though.

Tim

[robert.1.hall72202]

So I have an area returned, however, it isn't converted.
I have been messing around with converting the output
and I have not had any success. Where in this code do
I add the conversion?

(defun c:aw (/ e vlaobj)
(setq e (entget (car (entsel))))
(setq vlaobj (vlax-ename->vla-object (dxf -1 e)))
(vlax-get-property vlaobj 'Area)
);defun
(defun dxf (code elist)
(cdr (assoc code elist))
);defun
)