sort a list of points?..

ok.. i have a list of points that I need to sort twice.. once by x
cord, and once by y cord.

((12.99999 6.81111 0.0)(4582.61795 3247.13846 0.0)(ect....))

you get the idea..

x cord will need to be smallest to largest, and y cord will be largest
to smallest.

now how?

 

from vlisp help for vl-sort:

Sort a list of 2D points by Y coordinate:

(vl-sort '((1 3) (2 2) (3 1))
(function (lambda (e1 e2)
(< (cadr e1) (cadr e2)) ) ) )

Gives
((3 1) (2 2) (1 3))


C Witt <>
|>ok.. i have a list of points that I need to sort twice.. once by x
|>cord, and once by y cord.
|>
|>((12.99999 6.81111 0.0)(4582.61795 3247.13846 0.0)(ect....))
|>
|>you get the idea..
|>
|>x cord will need to be smallest to largest, and y cord will be largest
|>to smallest.
|>
|>now how?

James Maeding
Civil Engineer/Programmer

 

ok.. but one problem..

(vl-sort '((27.7521 19.0702 0.0)
(27.752 19.0702 0.0)
(27.7519 19.0702 0.0)
(27.7518 19.0702 0.0)
(27.7521 18.0702 0.0))
(function (lambda (e1 e2)
(> (cadr e1) (cadr e2)))))

returns a list of:
((27.7521 19.0702 0.0)
(27.752 19.0702 0.0)
(27.7519 19.0702 0.0)
(27.7518 19.0702 0.0)
(27.7521 18.0702 0.0))

when I want a list of:
((27.7518 19.0702 0.0)
(27.7519 19.0702 0.0)
(27.752 19.0702 0.0)
(27.7521 19.0702 0.0)
(27.7521 18.0702 0.0))

 

just change the cadr to whatever element you care about,
car for x, cadr for y, caddr for z....

C Witt <>
|>ok.. but one problem..
|>
|>(vl-sort '((27.7521 19.0702 0.0)
|>(27.752 19.0702 0.0)
|>(27.7519 19.0702 0.0)
|>(27.7518 19.0702 0.0)
|>(27.7521 18.0702 0.0))
|> (function (lambda (e1 e2)
|> (> (cadr e1) (cadr e2)))))
|>
|>returns a list of:
|>((27.7521 19.0702 0.0)
|>(27.752 19.0702 0.0)
|>(27.7519 19.0702 0.0)
|>(27.7518 19.0702 0.0)
|>(27.7521 18.0702 0.0))
|>
|>when I want a list of:
|>((27.7518 19.0702 0.0)
|>(27.7519 19.0702 0.0)
|>(27.752 19.0702 0.0)
|>(27.7521 19.0702 0.0)
|>(27.7521 18.0702 0.0))

James Maeding
Civil Engineer/Programmer

 

how will that help??.. (take a close look at the 2 lists)

 

i still want it to sort the y cord, i just want it to reverse how it
sorts the x cord at the same time..

 

One way:
(defun sort ()
(mapcar '(lambda(x) (nth x ptlst))
(vl-sort-i ptlst
'(lambda (a b)
(or (< (car a)(car b))
(and
(= (car a) (car b))
(< (cadr a) (cadr b))
)
)
)
)
))

;regards Doug

 

That should be:
(defun sort (ptlst)
(mapcar '(lambda(x) (nth x ptlst))
(vl-sort-i ptlst
'(lambda (a b)
(or (< (car a)(car b))
(and
(= (car a) (car b))
(< (cadr a) (cadr b))
)
)
)
)
))

 

change the > to < to sort in reverse,
looks like you are saying you want the points sorted by the x coordinate in increasing order,
then for any duplicates, sort the items by Y in decreasing order....

That would be better andled by sorting the list by X first, then running a loop to go through and resort any duplicates
by the Y in decreasing order

I'll write it if the other posts do not solve it...

C Witt <>
|>i still want it to sort the y cord, i just want it to reverse how it
|>sorts the x cord at the same time..
|>
|>James Maeding wrote:
|>
|>> just change the cadr to whatever element you care about,
|>> car for x, cadr for y, caddr for z....
|>>
|>> C Witt <>
|>> |>ok.. but one problem..
|>> |>
|>> |>(vl-sort '((27.7521 19.0702 0.0)
|>> |>(27.752 19.0702 0.0)
|>> |>(27.7519 19.0702 0.0)
|>> |>(27.7518 19.0702 0.0)
|>> |>(27.7521 18.0702 0.0))
|>> |> (function (lambda (e1 e2)
|>> |> (> (cadr e1) (cadr e2)))))
|>> |>
|>> |>returns a list of:
|>> |>((27.7521 19.0702 0.0)
|>> |>(27.752 19.0702 0.0)
|>> |>(27.7519 19.0702 0.0)
|>> |>(27.7518 19.0702 0.0)
|>> |>(27.7521 18.0702 0.0))
|>> |>
|>> |>when I want a list of:
|>> |>((27.7518 19.0702 0.0)
|>> |>(27.7519 19.0702 0.0)
|>> |>(27.752 19.0702 0.0)
|>> |>(27.7521 19.0702 0.0)
|>> |>(27.7521 18.0702 0.0))
|>>
|>> James Maeding
|>> Civil Engineer/Programmer

James Maeding
Civil Engineer/Programmer

 

"Looks like you are saying you want the points sorted by the x
coordinate in increasing order, then for any duplicates, sort the items
by Y in decreasing order"

yes, and i will also want another that sorts y in decreasing order, then
sorts duplicates of y by x in increasing order.. (I can do the latter if
i have a base to work from)..

TIA

 

C.,
Have you looked down the thread a bit?

"C Witt" <> wrote in message news:411d010f$1_3@newsprd01...

 

sry.. hadn't tried that yet.

i will as soon as i get a few minutes.

 

nice, good stuff

"Doug Broad" <>
|>That should be:
|>(defun sort (ptlst)
|> (mapcar '(lambda(x) (nth x ptlst))
|> (vl-sort-i ptlst
|> '(lambda (a b)
|> (or (< (car a)(car b))
|> (and
|> (= (car a) (car b))
|> (< (cadr a) (cadr b))
|> )
|> )
|> )
|> )
|> ))
|>
|>|>> One way:
|>> (defun sort ()
|>> (mapcar '(lambda(x) (nth x ptlst))
|>> (vl-sort-i ptlst
|>> '(lambda (a b)
|>> (or (< (car a)(car b))
|>> (and
|>> (= (car a) (car b))
|>> (< (cadr a) (cadr b))
|>> )
|>> )
|>> )
|>> )
|>> ))
|>>
|>> ;regards Doug
|>|>> > ok.. i have a list of points that I need to sort twice.. once by x
|>> > cord, and once by y cord.
|>> >
|>> > ((12.99999 6.81111 0.0)(4582.61795 3247.13846 0.0)(ect....))
|>> >
|>> > you get the idea..
|>> >
|>> > x cord will need to be smallest to largest, and y cord will be largest
|>> > to smallest.
|>> >
|>> > now how?
|>> >
|>>
|>>
|>

James Maeding
Civil Engineer/Programmer

 

Thanks James.

 

a long time in comming, but thank you.