Quadrants of a circle in a unique UCS

Hello guys.

I've been trying to keep up with all the lisps I can understand, and I've been getting better at it. so much so, I've written a few without any help!

But alas, I was bound for failure sooner or later. So I have come crawling back.

I have written this little lisp. i'm sure there are like 50 different versions of, it's to make a 3 point circle within those 3 point's UCS, without having to change UCS manually.

shown here:

;	3 point circle maker!!!!
;	11/06/13
;	Patrick Mitchell
;	kapatrick@gmail.com
; picks 3 points, makes those their own UCS and makes a circle in 1 easy step!
;
;

(defun c:3PC (/ p1 p2 p3 wp1 wp2 wp3)
(while ;start while

(setq p1 (getpoint "point1"))
(setq p2 (getpoint "point2"))
(setq p3 (getpoint "point3"))

(setq wp1 (trans p1 1 0))
(setq wp2 (trans p2 1 0))
(setq wp3 (trans p3 1 0))

(command "_ucs" "3p" p1 p2 p3)

(command "CIRCLE" "3P" (trans wp1 0 1) (trans wp2 0 1) (trans wp3 0 1))
(command "._ucs" "_w")

(princ)
) ;end while
)

(side note: I couldn't get "entmake" to work in this way. For some reason I couldn't get the DXF code and the "trans 0 1" to work. I usally like to use entmake so I can name my circles and lines and refer back to them.)

Now, here is where it get tricky. Cause I want to "improve" it, but very specifically.

Most this code I need works with "assoc" and "mapcar" I think.

What I am looking for is a way for when I create these circles, i'm looking for the quadrants of these circles, but in WCS. From what I suspect, this might be impossible. Because when you're in WCS, you can't pick quadrants of circles that are made within a unique UCS. So far i've been having to fake it out by creating a circle next to it, and rotate some quadrant lines in reference to my perfect circle.

Any ideas? or I would appreciate somebody to tell me it's impossible, so I don't go chasing a pipe dream for 2 weeks.

Thanks for your time!

The following example should perform correctly in all UCS & Views:

([color=BLUE]defun[/color] c:3pc ( [color=BLUE]/[/color] cn cr nv p1 p2 p3 rd )
   ([color=BLUE]if[/color]
       ([color=BLUE]and[/color]
           ([color=BLUE]setq[/color] p1 ([color=BLUE]getpoint[/color] [color=MAROON]"\n1st point: "[/color]))
           ([color=BLUE]setq[/color] p2 ([color=BLUE]getpoint[/color] [color=MAROON]"\n2nd point: "[/color] p1))
           ([color=BLUE]setq[/color] p3 ([color=BLUE]getpoint[/color] [color=MAROON]"\n3rd point: "[/color] p2))
       )
       ([color=BLUE]if[/color] ([color=BLUE]setq[/color] cr (LM:3PCircle p1 p2 p3))
           ([color=BLUE]progn[/color]
               ([color=BLUE]setq[/color] nv ([color=BLUE]trans[/color] '(0.0 0.0 1.0) 1 0 [color=BLUE]t[/color])
                     cn ([color=BLUE]trans[/color] ([color=BLUE]car[/color] cr) 1 nv)
                     rd ([color=BLUE]cadr[/color] cr)
               )
               ([color=BLUE]entmake[/color]
                   ([color=BLUE]list[/color]
                      '(0 . [color=MAROON]"CIRCLE"[/color])
                       ([color=BLUE]cons[/color] 010 cn)
                       ([color=BLUE]cons[/color] 040 rd)
                       ([color=BLUE]cons[/color] 210 nv)
                   )
               )
               ([color=BLUE]foreach[/color] x
                   ([color=BLUE]list[/color]
                       ([color=BLUE]list[/color] rd 0.0 0.0)
                       ([color=BLUE]list[/color] 0.0 rd 0.0)
                       ([color=BLUE]list[/color] ([color=BLUE]-[/color] rd) 0.0 0.0)
                       ([color=BLUE]list[/color] 0.0 ([color=BLUE]-[/color] rd) 0.0)
                   )
                   ([color=BLUE]entmake[/color]
                       ([color=BLUE]list[/color]
                          '(0 . [color=MAROON]"POINT"[/color])
                           ([color=BLUE]cons[/color] 010 ([color=BLUE]trans[/color] ([color=BLUE]mapcar[/color] '[color=BLUE]+[/color] cn x) nv 0))
                           ([color=BLUE]cons[/color] 210 nv)
                       )
                   )
               )
           )
           ([color=BLUE]princ[/color] [color=MAROON]"\nPoints are collinear."[/color])
       )
   )
   ([color=BLUE]princ[/color])
)

[color=GREEN];; 3-Point Circle  -  Lee Mac[/color]
[color=GREEN];; Returns the Center and Radius of the Circle defined by the supplied three points.[/color]

([color=BLUE]defun[/color] LM:3PCircle ( p1 p2 p3 [color=BLUE]/[/color] a b c d )
   ([color=BLUE]setq[/color] p2 ([color=BLUE]mapcar[/color] '[color=BLUE]-[/color] p2 p1)
         p3 ([color=BLUE]mapcar[/color] '[color=BLUE]-[/color] p3 p1)
         a  ([color=BLUE]*[/color] 2.0 ([color=BLUE]-[/color] ([color=BLUE]*[/color] ([color=BLUE]car[/color] p2) ([color=BLUE]cadr[/color] p3)) ([color=BLUE]*[/color] ([color=BLUE]cadr[/color] p2) ([color=BLUE]car[/color] p3))))
         b  ([color=BLUE]distance[/color] '(0.0 0.0) p2)
         c  ([color=BLUE]distance[/color] '(0.0 0.0) p3)
         b  ([color=BLUE]*[/color] b b)
         c  ([color=BLUE]*[/color] c c)
   )
   ([color=BLUE]if[/color] ([color=BLUE]not[/color] ([color=BLUE]equal[/color] 0.0 a 1e-)
       ([color=BLUE]list[/color]
           ([color=BLUE]setq[/color] d
               ([color=BLUE]mapcar[/color] '[color=BLUE]+[/color] p1
                   ([color=BLUE]list[/color]
                       ([color=BLUE]/[/color] ([color=BLUE]-[/color] ([color=BLUE]*[/color] ([color=BLUE]cadr[/color] p3) b) ([color=BLUE]*[/color] ([color=BLUE]cadr[/color] p2) c)) a)
                       ([color=BLUE]/[/color] ([color=BLUE]-[/color] ([color=BLUE]*[/color] ([color=BLUE]car[/color]  p2) c) ([color=BLUE]*[/color] ([color=BLUE]car[/color]  p3) b)) a)
                       0.0
                   )
               )
           )
           ([color=BLUE]distance[/color] d p1)
       )
   )
)

Lee, you are once again amazing to me. Close enough!

You're welcome Patrick