how to join selection sets

[Tharwat]

But i still want to see a function made by some guys with more experience ...please...

You should be thankful for all people whom treated you as a man to help you out with your question and not to be ungrateful .

[Lee Mac]

Here is one way:

;; Selection Set Union  -  Lee Mac
;; Returns the union of a list of Selection Sets

(defun LM:ss-union ( lst / out )
    (setq lst (vl-sort lst '(lambda ( a b ) (> (sslength a) (sslength b))))
          out (car lst)
    )
    (foreach ss (cdr lst)
        (repeat (setq i (sslength ss))
            (ssadd (ssname ss (setq i (1- i))) out)
        )
    )
    out
)

Here is a 'cheats' way:

(defun ss-union ( lst )
    (apply 'vl-cmdf (append '("_.select") lst '("")))
    (ssget "_P")
)

[drafter007]

Thanks Lee! One more beer i owe you...

[pBe]

Here is one way:

(defun LM:ss-union ( lst / out ).....
.....
)

There you go

After looking the linky MSasu posted on his previous post. My thought was the "list with multiple selection sets" you are refering to are a list of enames as elements. but reading further ahead , you change your aapproach to collecting points then
ssget "_CP"

But anyhoo, Hope you dont mind me asking, are those selection sets resulted from a single call to a lisp routine?

[drafter007]

Yes, a single call, but i modified the lisp to have multiple selection - multiple points of selection - so i have a list with multiple selection sets...
Sorry for my way of working and for my bad explanations...

[Lee Mac]

Thanks Lee! One more beer i owe you...

You're welcome drafter007, though, I would encourage you to attempt to code these tasks yourself before expecting a solution to be provided.

[marko_ribar]

Only with express tools... nobody has a function similar to acet-ss-union?

Every AutoCAD has ACET functions loaded and no need to do anything but use them...

My solution is fastest as it was made by Autodesk for exactly these purposes...

You can also check :
(acet-ss-remove (smaller ss2) (bigger ss1)) - returns ss difference (ss1-ss2)
(acet-ss-intersection ss1 ss2) - returns ss with objects that are both in ss1 and ss2

(acet-ss-union (list ss1 ss2 ss3 ... ssn)) - returns ss addition (ss1+ss2+ss3+...+ssn)

M.R.

[pBe]

I'll go with the OP on this one Marko. I would think its not the just having to use a particular function that interest the OP, but how it was done

I applaud the forum members who help/assist/advice/suggest and even write the code itself to help others.

Cheers

[marko_ribar]

pBe, I've also tried this once on www.augi.com :
http://forums.augi.com/showthread.ph...functions&p=#1

But results were slow if ssets were large, so after a while doing my research on this topic, my conclusion was that the best thing is to use already predefined functions... Maybe, you don't agree with me, but to me they do the job fine and more important I think faster then any of above proposed codes...

M.R.
(test it and if you disagree reply...)

[Lee Mac]

Every AutoCAD has ACET functions loaded and no need to do anything but use them...

Some users don't have Express Tools installed / loaded.