Select by Elevation?

[cchiles]

Hello - Let me first say, I have dabbled a bit in writing lisp.
Does anyone have or can point me in the right direstion to a lisp that can select ALL objects at a given Z elevation? Either inputed or selected. I have searched and searched for a way to do this, but have come up with nothing.

Thanks,
Chris

[Opie]

Have you tried using the filter command in AutoCAD? The filter command will allow you to set up the criteria for your selection set.

Or even the qselect command? I have not used the qselect command much and therefore do not have much experience with it.

[cchiles]

Yea - I have - Qselect will only allow you to do it on a per entity basis & I couldn't find a way to have filter give me the elevation as selection criteria.

Chris

[CAB2k]

Something along these lines might work.
(setq elev 144.0)

(setq ss (ssget "X"
(list '(-4 . "<OR")
(cons 38 elev)
'(-4 . "*,*,=")
(list 10 0.0 0.0 elev)
'(-4 . "*,*,=")
(list 11 0.0 0.0 elev)
'(-4 . "OR>")
)
)
)