lisp routine to quick select by elevation

is there a way to quick select polylines by elevation???

i have this elevations something like 1, 1.3, 1.5, and 1.6, 2, 2.5

so i want to select from 1 to 1.5 and put it on a layer, and from 1.6 to 2.5 put on different layer....

is it possible to quick select by elevation

From a side view you could do this.

not very lispy but practical..

Another non lisp approach would be using the FILTER command.

The way I set this up, the FILTER is actually searching for all Polylines with Elevations in the RANGE from 1 to 1.5, but that can be easily altered.

Once you set up such a Filter, you can save it as a preset, so the next time you need it, all you need to do is to select it from the dropdown Named filter menu.

QuickSelect will not allow you to do a range like this, or multiple elevations in one search.

(defun spelv (lo hi)
  (ssget (list '(0 . "LWPOLYLINE") '(-4 . ">=") (cons 38 lo) '(-4 . "<") (cons 38 hi)))
)

Suggest you take a look at Lee Mac's page on ssget filters

http://www.lee-mac.com/ssget.html

Once you got the selection set, It's only a matter of using entmod to change the layer

of every entity in it.

(defun spelv (lo hi)
  (ssget (list '(0 . "LWPOLYLINE") '(-4 . ">=") (cons 38 lo) '(-4 . "<") (cons 38 hi)))
)

 

Suggest you take a look at Lee Mac's page on ssget filters

 

http://www.lee-mac.com/ssget.html

 

Once you got the selection set, It's only a matter of using entmod to change the layer

of every entity in it.

i didnt get the code

A bit more

(defun c:spelv ( / lo hi)
  (setq ss (ssget (list '(0 . "LWPOLYLINE") '(-4 . ">=") (cons 38 (getreal "enter low value")) '(-4 . "<") (cons 38 (getreal "Enter high value")))))
  (command "-chprop" ss "" "La" (getstring "Enter Layer name") "")
)