Polyline acreage calc

[jagielski]

I've found a lisp routine to calculate acreage of multiple polylines at the same time. This works fine if the linetype generation of the polyline is disabled but will not work on enabled linetype generation. I don't know much at all about lisp. Would anybody have any clue why this is and if there is a way to change it?

[Alfred.NESWADBA]

Hi,

>> This works fine if the linetype generation of the polyline is disabled but will not work on enabled linetype generation

Can you please upload the drawing (with a polyline) that shows different values when linetype-generation is switched?

And is the area value also different in the property window?

Why do I ask that? Because I don't understand why linetype-generation should make any difference for the calculation of a polylines area.

- alfred -

[jagielski]

Alfred,

This doesn't make any sense to me either. I'm using ACAD Map 3D 2012. I've attached a simple drawing but the lisp I attached earlier won't work with any polygon that is set to enabled on linetype generation. It doesn't recognize that anything has been selected and gives an error message when I exit out. ; error: bad argument type: fixnump: nil

If I change the linetype generation to disabled on that same polyline the lisp routine will do exactly what I want it to and report the acreage for me.

Thank you,

Kraig 

[Alfred.NESWADBA · Accepted solution]

Hi,

remove that part from the ssget part

(70 . 1)

...remove that including the 2 brackets, save the file, reload it (or restart AutoCAD and load it).

I'm not sure why that is necessary as that filter checks if a polyline or lwpolyline is closed or not, but in that case it seems to have troubles witht he linetype generation flag. If you need more details about it please ask in the Lisp-forum >>>here<<< as my LISP knowledge is close to nothing, the other forum is full of LISP gurus 😉

- alfred -

[jagielski]

Alfred,

Thank you.

I also found that if I added (-4 . "&") just before the (70 . 1) that this also fixed my problem. I have no idea what this does. Like I said before I do not have any lisp knowledge except to utilize what I find and modify here and there (barely) to make it fit my needs.

I appreciate the help. I'm going to have to spend some time on the lisp forum to see if I can learn a thing or too.

Kraig