Helmert Transformation

Does anyone has routine for helmert transformation?

https://en.m.wikipedia.org/wiki/Helmert_transformation

Maybe this could be of interest to you? Though I'd share:

https://apps.autodesk.com/ACD/en/Detail/Index?id=3236793333071302608&appLang=en&os=Win32_64

Thank you... but I wrote this function

I see. After browsing, I came across this. Again just thought I would share. Not sure if its what your looking for or not.

;;;;   Graphical Helmert's transformation
;;;;   ----------------------------------
(defun C:Helmert ( / lun lup aun aup ang ib1 ib2 x1 y1 X2 Y2
            q ib xt1 yt1 Xt2 Yt2 t1 t2 dx dy ir Xx Yy xr yr
                    a1 a2 b1 2b c1 c2 sa1 sa2 sb1 sb2 sc1 sc2
                    at bt qt wt wtr wtd scl et)

 (setq lun (getvar "LUNITS"))
 (setq lup (getvar "LUPREC"))
 (setq aun (getvar "AUNITS"))
 (setq aup (getvar "AUPREC"))
 (setq ang (getvar "ANGDIR"))

 (setvar "LUNITS" 2)
 (setvar "LUPREC" 3)
 (setvar "AUNITS" 2)
 (setvar "AUPREC" 4)
 (setvar "ANGDIR" 1)

 (setq ib1 (getpoint "\n 1òî÷êà Èñòî÷íèêà : "))
 (setq ib2 (getpoint ib1 "\n 1òî÷êà Öåëè : "))
 (setq x1 (list (car ib1)))
 (setq y1 (list (cadr ib1)))
 (setq X2 (list (car ib2)))
 (setq Y2 (list (cadr ib2)))
 (grdraw ib1 ib2 5)

 (setq ib1 (getpoint "\n 2òî÷êà Èñòî÷íèêà : "))
 (setq ib2 (getpoint ib1 "\n 2òî÷êà Öåëè : "))
 (setq x1 (append x1 (list (car ib1))))
 (setq y1 (append y1 (list (cadr ib1))))
 (setq X2 (append X2 (list (car ib2))))
 (setq Y2 (append Y2 (list (cadr ib2))))
 (grdraw ib1 ib2 5)
 
 (setq q "Y"
   ib 2)
 (while (/= q "N")
   (initget "Y N")
   (setq q (getkword "\n Ñëåäóþùàÿ òî÷êà? Yes/No <Y> : "))
   (if (or (= q "y") (= q "Y") (= q nil))
     (progn
       (setq ib1 (getpoint "\n Ñëåäóþùàÿ òî÷êà Èñòî÷íèêà : "))
       (setq ib2 (getpoint ib1 "\n Ñëåäóþùàÿ òî÷êà Öåëè : "))
       (setq x1 (append x1 (list (car ib1))))
       (setq y1 (append y1 (list (cadr ib1))))
       (setq X2 (append X2 (list (car ib2))))
       (setq Y2 (append Y2 (list (cadr ib2))))
   (setq ib (+ 1 ib))
       (grdraw ib1 ib2 5)
     )
   )
 )

 (setq xt1 0.0
   yt1 0.0
   Xt2 0.0
   Yt2 0.0)
 (foreach p x1 (setq xt1 (+ xt1 p)))
 (foreach p y1 (setq yt1 (+ yt1 p)))
 (foreach p X2 (setq Xt2 (+ Xt2 p)))
 (foreach p Y2 (setq Yt2 (+ Yt2 p)))
 (setq xt1 (/ xt1 ib))
 (setq yt1 (/ yt1 ib))
 (setq t1 (list xt1 yt1))
 (setq t2 (list (/ Xt2 ib) (/ Yt2 ib)))
 (setq dx (- (nth 0 t2) (nth 0 t1)))
 (setq dy (- (nth 1 t2) (nth 1 t1)))
 
 (grdraw t1 t2 6)

 (setq ir 0)
 (setq Xx nil
   Yy nil
   xr nil
   yr nil)
 (while (< ir ib)
   (setq Xx (append Xx (list (- (nth ir X2) (nth ir x1)))))
   (setq Yy (append Yy (list (- (nth ir Y2) (nth ir y1)))))
   (setq xr (append xr (list (- (nth ir x1) xt1))))
   (setq yr (append yr (list (- (nth ir y1) yt1))))
   (setq ir (+ 1 ir))
 )
 
 (setq ir 0)
 (setq a1 nil
   a2 nil
   b1 nil
   b2 nil
   c1 nil
   c2 nil)
 (while (< ir ib)
   (setq a1 (append a1 (list (* (nth ir Xx) (nth ir xr)))))
   (setq a2 (append a2 (list (* (nth ir Yy) (nth ir yr)))))
   (setq b1 (append b1 (list (* (nth ir Yy) (nth ir xr)))))
   (setq b2 (append b2 (list (* (nth ir Xx) (nth ir yr)))))
   (setq c1 (append c1 (list (* (nth ir xr) (nth ir xr)))))
   (setq c2 (append c2 (list (* (nth ir yr) (nth ir yr)))))    
   (setq ir (+ 1 ir))
 )

 (setq ir 0)
 (setq sa1 0.0
   sa2 0.0
   sb1 0.0
   sb2 0.0
   sc1 0.0
   sc2 0.0)
 (while (< ir ib)
   (setq sa1 (+ sa1 (nth ir a1)))
   (setq sa2 (+ sa2 (nth ir a2)))
   (setq sb1 (+ sb1 (nth ir b1)))
   (setq sb2 (+ sb2 (nth ir b2)))
   (setq sc1 (+ sc1 (nth ir c1)))
   (setq sc2 (+ sc2 (nth ir c2)))
   (setq ir (+ 1 ir))    
 )

 (setq at (/ (+ sa1 sa2) (+ sc1 sc2)))
 (setq at (+ 1 at))
 (setq bt (/ (- sb1 sb2) (+ sc1 sc2)))
 (setq qt (sqrt (+ (* at at) (* bt bt))))
 (setq wt (atan bt at))
 (setq wtr (* (1- 0) (/ (* 200.0 wt) pi)))
 (setq wtd (* (1- 0) (/ (* 180.0 wt) pi)))  

 (setq q "Y")
 (initget "Y N")
 (setq q (getkword "\n Ïðèìåíèòü ìàñøòàáèðîâàíèå? Yes/No_(q=1)/User  <Y> : "))
 (if (or (= q "y") (= q "Y") (= q nil))
   (setq scl qt)
 )
 (if (or (= q "n") (= q "N"))
   (setq scl 1.0)
 )
 (if (or (= q "u") (= q "U"))
   (setq scl (getreal "User's scale : "))
 )
 (setq et (ssget))
 (setq q "N")
 (initget "N Y")
 (setq q (getkword "\n Ñîõðàíèòü îðèãèíàë? No/Yes <N> : "))
 (if (or (= q "y") (= q "Y"))
   (command "_copy" et "" "0,0,0" "0,0,0") 
 )
 (command "_move" et "" "_none" t1 "_none" t2)
 (command "_rotate" et "" "_none" t2 wtr)
 (command "_scale" et "" "_none" t2 scl)

 (princ
   (strcat "\n  dY : " (rtos dx 2 3) "    dX : " (rtos dy 2 3)
    "\n  w  : " (rtos wtr 2 4) "g    " (rtos wtd 2 5) "°    q : " (rtos scl 2 
   )
 )  

 (setvar "LUNITS" lun)
 (setvar "LUPREC" lup)
 (setvar "AUNITS" aun)
 (setvar "AUPREC" aup)
 (setvar "ANGDIR" ang)

)
;======Konec

in English

helmert_en.lsp