Cutting up an ellipse ..

[ethan]

I have an oval room that I measured around the perimeter as to door
placement .. now that I am back in my office, I am attempting to plot out
where the doors fall on the ellipse.

The ellipse is 85'w x 116'L

with breaks for Doors from 0 (being the bottom center quad of the ellipse)
as follows:

0 --> 38.5
13'4 --> 16'6
30'11 -->34'4

along the circumference of the ellipse / perimeter of the room

any ideas on how to plot this out?

thanks,
Ethan

[Michael Bulatovich]

Assuming that you are measuring an existing room, how do you know it's an
ellipse? BTW, an ellipse is an oval but an oval is *not* necessarily an
ellipse.
If you draw an ellipse, and then list it you will find that you will get the
circumference. If you trim an ellipse with a line what's left is an ellipse
and a LIST will give you its length. With this in mind and some constructive
geometry you should be able to piece this together, if the room is an
ellipse.
--

MichaelB
www.michaelbulatovich.com

"ethan" <nospam...@19d.org> wrote in message
news:rRa7a.34731$Mh3.14...@twister.nyc.rr.com...

[Paul Turvill]

I'd probably start by breaking the ellipse at the nominal "zero" point, then
use the MEASURE command to locate each door, erasing the unneeded points
after each execution.
___

"ethan" <nospam...@19d.org> wrote in message
news:rRa7a.34731$Mh3.14...@twister.nyc.rr.com...
>

[Longshot]

I would use "divide" command to set points at every foot or half foot,,,
that would get you close, then stretch & List until my measurements were on.
you may need to trace the ellipse into Pline arcs & segments,,, I have found
that necessary from time to time

--
be cool,

Longshot

[Longshot]

> I'd probably start by breaking the ellipse at the nominal "zero" point,
then
> use the MEASURE command to locate each door, erasing the unneeded points

I wasn't familiar with this command,,, but tried it.. this would be the way
to go.
learn something new every day... & sometimes it's actually useful :p)

Rob

[P.C.]

Hi

"Longshot" <longs...@aol.com> skrev i en meddelelse
news:b3ktu5$1n0k54$1...@ID-93768.news.dfncis.de...

Then the sysvar Pdmode and Pdsize will be handy ,as this way the points can be
produced in a style and size so you can se them.
P.C.

[Longshot]

>
> Then the sysvar Pdmode and Pdsize will be handy ,as this way the points
can be
> produced in a style and size so you can se them.
> P.C.
>

yeah, that's a given as I use "divide" allot. :p)

[ethan]

thanks .. but how do you set the start point of the measure?

If it divides unequally, then I'm left with an odd segment .. I need to
identify my zero point ..

but not sure how ..

"ethan" <nospam...@19d.org> wrote in message
news:rRa7a.34731$Mh3.14...@twister.nyc.rr.com...

[Longshot]

draw your horiz & vert axis lines first , draw your ellipse by picking the
end points. make 3 copies , trim each from zero,,, to 270deg (or wherever
you want outside of your perimeter range.

like PC said... format your point style & size so you can see where the
Measure command marks it

be cool,

Longshot
"

[Paul Turvill]

BREAK the ellipse at the point from where you started measuring. Then use
the MEASURE command to place a point (and other points) a fixed distance
from the break. That's your first door location. Erase the points; MEASURE
again for the next door, etc.
___

"ethan" <nospam...@19d.org> wrote in message

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[ethan]

thank you all very much

"ethan" <nospam...@19d.org> wrote in message

news:rRa7a.34731$Mh3.14...@twister.nyc.rr.com...

[P.C.]

Hi

"Paul Turvill" <nos...@turvill.com> skrev i en meddelelse
news:v5sco9a...@corp.supernews.com...

> BREAK the ellipse at the point from where you started measuring. Then use
> the MEASURE command to place a point (and other points) a fixed distance
> from the break. That's your first door location. Erase the points; MEASURE
> again for the next door, etc.

I used Measure and Divide a lot to generate "primitive" 3D-Polylines , and I
simply made a small app ; This make a list with the first point of the line
that is divided as first member , then before doing the divide or measure trick
, a new layer are created and set current as when Divide or Measure generate
the points ,they will be created in a "row" on the current layer , ---------- so
when filtering out the assoc 10 of each point to append the list , everything
work smooth while the points are created this way , and then Ssget will also
find the entity type "Point" on the specific layer and then appending them is no
trouble ; --------- still as the first point need to be taken from the entity
divided, the last point also need to be taken from the entity divided or
measured, still as you all know, this is no problem with Lisp .
BTW I even made my own divide function ; ------- you "walk" this many drawing
units from this point in "this" direction , then if the first vector is long
enough you add that point. Case the first vector in this direction is not long
enough, you subtract it's length from the distance you would "walk" , and se
where the remaining distance fit with the next vector, case that is also to
shirt, you subtract this length and try "walk" from that point in this new
direction to se if you can place a point this time ;))
--------- I got it working, guess this was with ver 2.6 , to get the tools I
needed.

Anyway the first point you proberly will find with (entget(car(entsel))) from
the entity divided and the last point proberly are to be found in the entity to.

P.C.

[David]

If you set the variable "pellipse" to 1 then an ellipse is drawn as a series
of polyline segments rather than a true ellipse, save having to trace over
it.

Regards to all .........

"Longshot" <longs...@aol.com> wrote in message
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