Measuring areas

[rusty]

I need to calculate the areas within a set of lines that form a closed area.

1. How do I do that?

2. Do I need to create a polyline around the area, or is lines enough?

I use AutoCad Map 2000i
Thanks in advance

[CADTutor]

You cannot calculate the area bounded by lines, so you will need to use polylines. Check out the BOUNDARY command as this could be used to create closed polylines from your lines. Also have a look at the AutoLISP archive for a routine that will calculate total area from all polylines on a specific layer.
http://cadtutor.net/forum/viewtopic.php?t=1505

[fahim108]

If the shape isn't much complicated, try using the AREA command. Then pick up all the corners (end points) of the shape, one by one, along the perimeter, and hit enter. Although this is a tedious process and doesn't work for curved boundaries, still knowing about it is better!

[rusty]

That should help a lot - Thanks!

[slimjramirez]

I love this forum.
never fails meh.

[StykFacE]

I love this forum.
never fails meh.

:cat:

[Raggi_Thor]

It's an interesting question, even if it's old now.



You can do it manually like this:

Command: bo BOUNDARY + ENTER

Select internal point: (Click)

BOUNDARY created 1 polyline

Command: area

Specify first corner point or [Object/Add/Subtract]: o

Select objects: last

Area = 17500000.000, Perimeter = 17000.000

Command: (/ (getvar "area") 1000000.0)

17.5

(This means the area in square meter is 17.5 if the drawing unit is mm)






Or you can make a new button (Command: CUI) with a macro like this:

^C^C-Boundary;\;Area;O;Last;Erase;Last;;(/(getvar "area")1000000.0);

The Lisp part doesn't work in LT (unless you install LT Extender).
Normally you would make a block for room info if you are working with buildings. STATSBYGG in Norway has made a block for room number, function, area etc. that they demand that you use in their projects. They manage "all" public buildings in Norway.

mvh, Kvedja, Kind Regards,
Ragnar Thor Mikkelsen
www.DESIGNDATA.no

[Hefron]

Can anyone tell me how can I link block to an area so when I change the size of an area the values in block will update automatically?

[ReMark]

A block or a label?

[Raggi_Thor]

These are the commands you use,
ATTDEF to define the attributes.
This command has the option to use a FIELD as a default value.
In the FIELD dialog, select obect, select your pline, the select Area and formatting if you like.
Then define your block.

The problem is that all instances of this block, every insert, will be linked to that one pline you selected.

I did this in Bricscad, but I bet AutoCAD is practically idential.