Scale calculation problem

[rseyda]

I have a statement in a lisp routine that is supposed to scale items based on user input scale factors. The different scale factors are 1, 4, 8, 12, 16, 24, 32, 48 and 96. The statement works when scaling up (i.e. from 4 to 32, etc...). But when I try to scale down (i.e. 32 to 4, etc...) it still scales the objects up instead of down. Could someone look at this lisp to see what is wrong?

Thanks,

(defun c:scd ( / xfrom xto xinsert xdetail xretrieve sf) (setq xdetail (ssget)) (setq xfrom (getint "\nCurrent scale factor: ")) (setq xto (getint "\nNew scale factor: ")) (if (> xfrom xto)(setq sf (/ xfrom xto))(setq sf (/ xto xfrom))) (setq xretrieve (getpoint "\nScale from box : ")) (setq xinsert (getpoint "\nScale to box : ")) (command "scale" xdetail "" xretrieve sf) (command "move" xdetail "" xretrieve xinsert)
)

 

[David Bethel]

Watch out for division of integers

(/ 3 2)

returns 1

Try:
(/ 3 (float 2))
(/ 3 2.)

-David

 

[Tom Smith]

You're forcing it to always enlarge, by changing the ratio depending on whether xfrom > xto. You don't need that, the ratio should always be xto/xfrom. If you're going from 32 to 8, you need to divide xto/xfrom = 8/32=1/4. From 8 to 32 would be xto/xfrom=32/8=4.

I have a statement in a lisp routine that is supposed to scale items based

on user input scale factors. The different scale factors are 1, 4, 8, 12, 16, 24, 32, 48 and 96. The statement works when scaling up (i.e. from 4 to 32, etc...). But when I try to scale down (i.e. 32 to 4, etc...) it still scales the objects up instead of down. Could someone look at this lisp to see what is wrong?

 

[Thomas Smith]

Yeah! That's the ticket!
Also, look at adding (Float X) to 1 of the numbers (like David Bethel said above...)

 

[Paul Turvill]

Just use (getreal ...) instead of (getint ...) to obtain your inputs. That way you'll be dividing reals instead of integers.
___

So what would be the proper code in this matter then? Don't I need some

kind of IF statement to determine which number is higher so I can then tell it which way to divide?