/* CMD: Point Center
 * Find average point position, like center of mass
 * By Arnie Cachelin © 1993 NewTek Inc.
 *
 */
	mxx="LWModelerARexx.port"
	signal on error
	signal on syntax
  numeric digits 5
	mxx_add = addlib(mxx,0)
	call addlib("rexxmathlib.library",0,-30,0)
	call main
	if (mxx_add) then call remlib(mxx)
	exit

	syntax:
	error:
	t=Notify(1,'!Rexx Script Error','@'ErrorText(rc),'Line 'SIGL)
	if (mxx_add) then call remlib(mxx)
	exit


main:
  call sel_mode(USER)
  c=xfrm_begin()
  sx=0; sy=0; sz=0
  do i=1 to c
    v=xfrm_getpos(i)
    sx=sx+word(v,1)
    sy=sy+word(v,2)
    sz=sz+word(v,3)
    v=sx/c sy/c sz/c
    end
  call Notify(1,c" Points","!Point Center:",v)
  return

Magnitude: PROCEDURE
  arg v
  return(sqrt(Dot(v,v)))

Dot: PROCEDURE
  arg v1,v2
  S=0
  do i=1 to 3
    S=S+word(v1,i)*word(v2,i)
    end
  return S

Dist: PROCEDURE
  arg v1,v2
  S=0
  do i=1 to 3
    S=S + (word(v2,i) - word(v1,i))^2
    end
  return sqrt(S)