Expert: J. B. Borge - 2/14/2006

Question
Recently I've had to do several volume calculations for piping that we're doing.  I have set up an excel sheet so all I have to do is enter the length of the piping and it will give me volume.

I have had little c++ and MATLAB experience and could write a simple program if I knew the syntax for lisps.

What I need the program to do: let me select several lines at a time; then it takes the length of those lines and adds them to give me total length(in x'-x").  That way I don't have to add up all the lines one by one.

If you could help me on this it would be much appreciated.  Thanks!

PS. This is AutoCAD 2006

Answer
Nathan,

Here's a lisp function i use to calculate perimeters & areas & can be easily edited to your needs. The caveat, autocad can't add line lengths unless they are converted in polylines first.

;;;Start Copy Here
(defun c:CTA (/ a ss n du)
 (setq a 0
       b 0
       ;du (getvar "dimunit")
       ss (ssget '((0 . "*POLYLINE")))
 )
 (if ss
   (progn
     (setq n (1- (sslength ss)))
     (while (>= n 0)
       (command "_.area" "_o" (ssname ss n))
       (setq a (+ a (getvar "area"))
           b (+ b (getvar "perimeter"))
             n (1- n)
       )
     )
     (setq SQFT (strcat (rtos a 2 3) "  Sq. Ft.")
           SQYD (strcat (rtos (/ a 9) 2 3) "  Sq. Yd.")
           ACRE (strcat (rtos (/ a 43560) 2 3) "  Acres")
        PERI (strcat (rtos b 2 3) "  Ln. Ft.")
     )
     (princ "\nThe total area:  ")(princ SQFT) (terpri)
     (princ "                 ")(princ SQYD) (terpri)
     (princ "                 ")(princ ACRE) (terpri)
    (princ "                 ")(princ PERI) (terpri)
   )
   (alert "\nNo Polylines selected!")
 )
 (princ)
)
;;;End Copy Here

Load the routine & type CTA to run it. Hope this points to the right direction. Let me know!

Regards,
JB