# Thread: Help to calculate Area!

1. ## Help to calculate Area!

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I need help to calculate area of multiple closed polyline shapes. In my drawing I could have hundreds of shapes as shown in the picture. I want to find total of the shaded area by adding the area of the outer shapes. Then subtracting the area of the Inner shapes.

Area2.jpg

Maybe there is a better way to do it? Any help would be appreciated.

Thanks.

2. Welcome to the forum.
Are they all HATCHED with a SOLID HATCH like these seem to be?
The area of all hatches, or if not all, selected ones, or FILTERED ones could be found.

3. When in doubt check LEE MAC out .....
http://www.lee-mac.com/totallengthandarea.html
Thanks Lee!

Welcome to the forum.
Are they all HATCHED with a SOLID HATCH like these seem to be?
The area of all hatches, or if not all, selected ones, or FILTERED ones could be found.

The shapes are not are not hatched... I hatched them only to help illustrate the area that i want calculated..

5. Did you click the LEE MAC link, and look at the total area function in that lisp?

Did you click the LEE MAC link, and look at the total area function in that lisp?
I am evaluating that routine right now..

7. I tried LEE MAC's routine for total area. This is good, however this takes all the shapes and adds all the areas together. Maybe I'm not thinking about this the right way.

What I need is the sum of all the outer shapes and then subtract the sum of all the inner shapes. I am going to try to create the routine myself. Its been a while since I've done a custom lisp. I think its just a matter of creating a couple of selection sets, one for the outer shapes and one for the inner shapes. Figuring out the total area for each and then subtracting.

We'll see how it goes..

8. You could very easily use the FILTER command, set it up to only select items you are after, then use the lisp on the selection set, or GROUP them.

You could very easily use the FILTER command, set it up to only select items you are after, then use the lisp on the selection set, or GROUP them.

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If you get the FILTER set up so that you are happy with it, be sure to SAVE AS in the filter dialog box, so that it will be available
right out of the gate when you need it another time.
It is a very powerful and useful tool.
I have about 8 different saved filters which I routinely use, and it is very helpful not having to redefine them each time I want to use them.
You can also start from one of your saved FILTERS and then add or subtract items, to suit a specific search selection.