determining the area of a shape

[td88]

Is there a command that will tell me the area of the attached shape without turning into a polyline, by simply selecting the objects which make up its perimeter? I tried "area" but, it seemed to refuse to read the arc as an arc and, instead read it as a series of points connected by straight lines. When I turned the shape into a polyline, I got the desired answer but, would like to go through fewer steps.

Shape to Cadtutor.pdf

[ReMark]

You want a command that will allow you to pick inside the group of lines and then tell you the area. Not part of regular AutoCAD that I know of. Maybe someone has developed a lisp routine that does it.

[ReMark]

I tried the area command using the option to specify an arc which worked. But when I compared the result to the one I got after using Pedit to turn it into a closed polyline the two were different. I see what you mean now. I'd have to play around with it some more to see if I could get the exact same results.

 

Addendum:

 

I gave it a second try using your example and set up three test objects. The first consist of the three lines and the arc. The second was a closed polyline. The third was a hatch of the closed polyline. All three returned the exact same square footage. The difference this time was when I used the arc option I decided to input the radius and pick the two end points. Personally, I think this is just as much work, if not more than, turning the objects into a closed polyline.

 

You could always do the Pedit (Multiple option), get the area then "Undo".

[td88]

Hi Remark,

 

I don't necessarily want to just pick inside the area (although that would be nice), I expected to be able to pick the perimeter objects and do a "list", or something similar and get an area. When I picked the four corners, only, it gave me the area of the square and, when I picked points on the arc and the four corners, it gave me an area, as if the arc points were connected by straight lines connecting my pick points. Would seem simple enough to give the bounded area displayed on screen but, no luck.

 

Tim

[ReMark]

You cannot pick points on the arc. Like I said, you need to use the Arc option then type R (for radius), insert the radius then pick both endpoints. The last step is to choose CLose. The program will then return the area.

 

I think an area command with a "window" option would be more suitable to your purposes.

[td88]

When I did a pedit and made all a polyl, I got a different answer from all, indicating to me the entire shape was read, with the arc as an arc. The area was the lowest number of the three and, I'm guessing, the most accurate.

 

When you say "I used the arc option I decided to input the radius and pick the two end points.", what command were you in? In 2006 lt, I have no arc option in the area command.

 

I agree about the amount of work. That's why I was asking if I could simply pick the perimeter and get an answer. That would be the least work.

[ReMark]

Unfortunately the area command does not operate like the hatch command where you can make one pick inside an object.

 

Re: area command and arc option. The arc option does not appear until after the user has made their very first pick. It should show up on the command line as Specify next point or [Arc/Length/Undo]. 2006 doesn't do this?

[td88]

Hey Remark,

 

When "area" starts I get "Specify first corner point or [Object/Add/Subtract]".

I pick my first point and get "Specify next corner point or press ENTER for total". That message continues until I enter and get a total. This is true in 2006 LT and full.

[ReMark]

I'm sorry to hear that. I was hoping AutoDesk introduced the option earlier. Typically I will convert my objects to closed polylines prior to obtaining the area. I think that is because I'd rather work with polylines than lines. Force of habit I suppose.

 

Have you had a look for any custom area lisp routines that operate like the one I have mentioned?

[td88]

I haven't, because lisp is an area I'm totally unfamiliar with. Any suggestions on how to learn the basics?

[ReMark]

I'm sorry...I should have realized were we talking about LT not full AutoCAD. LT cannot use Lisp. You are out of luck.

[td88]

I have Acad 2006 full, also.

[SEANT]

How about this command macro; it may be compatible with both full and AutoCADLT. Just pick in an enclosed area, then “enter”.

 

^C^C-boundary;\\Area;o;Last;;;_erase;Last;;setvar;area;

[td88]

Hi SEANT,

 

I don't know macros or lisp. What do I do with the macro you sent?

 

Thanks,

 

Tim

[SEANT]

It could be added to a new toolbar button with the CUI command. See the response I made in post #6 of this thread.

 

http://www.cadtutor.net/forum/showthread.php?t=44795

[td88]

Hey SEANT,

 

Sorry, your post 6 doesn't help much with the uninitiated, I don't know what I'm looking at with CUI or how to use it. I will do a little reading in my Acad text and see if there are directions there. Thank you for sending it.

 

Tim

[Lee Mac]

If you are using the full version:

 

http://www.cadtutor.net/forum/showthread.php?t=46420

 

http://www.cadtutor.net/forum/showpost.php?p=311693&postcount=20

[Rob-GB]

 

If the object is a polyline, click on it then right click choose Properties then look down list under Geometry...Area.

Does this help in LT? (this was drawn as metric, mm's)

Rob.

[td88]

Thank you, Rob,

 

Making my (line or spline combined with polyline shapes) into a polyline and getting an area with list or properties was how this whole thing started. I wanted to avoid having to join my random stuff into a polyline and wondered if I could simply select the variety of things (in the case of the example sent, an arc and three lines) that make up the perimeter and use some command to get an area.

 

I'm liking what SEANT sent in #13 but, don't have the knowledge to place it properly in the CUI. I'm working on it. If you've seen a tutorial on how to create a toolbar button in CUI, I'd welcome it.

 

Tim

[td88]

If you are using the full version:

 

http://www.cadtutor.net/forum/showthread.php?t=46420

 

http://www.cadtutor.net/forum/showpost.php?p=311693&postcount=20

 

Lee Mac,

 

Thank you for sending the lisp, however, lisp is not one of my skills, so I'm not able to make use of your thread links. If you recommend text or tutorial for learning lisp, I'd be interested.

 

Tim