Lisp: Extract highest/lowest value from a list

[ajs]

O.K, If I have a list, is there a function that will allow me to extract the highest value and/or lowest value?

 

I don't care about duplicates.

 

In thinking about this, I could probably accomplish this task by using nth values and performing comparisons but that seems tedious. I was hoping I could do it in a single shot with a function.

 

Sample:

 

(setq MyList ((2.00000 26.0000 26.0000 25.6250 25.6250 3.00000 3.00000 2.00000))

 

This is what I'm after:

 

(setq LowVal (MyList))

 

(setq HighVal(MyList))

 

Thanks again for any help

 

---AJS

[CarlB]

ajs,

 

From your questions, you really need to get a reference with all the lisp functions to scan through, even search.

 

See 'max & 'min functions....

[ajs]

Thanks for the reply. I think you're right about the search function. I do have a function list but sometimes after reading it over and over, I find that I will (through carelessness) skip over something.

 

An example would be my earlier question on length, for some reason, I thought that the length function applied to strings and thus I didn't examine it properly.

 

I'm going to go online and see if I can find a searchable lisp function list.

 

I do appreciate the help of course. Thank you

 

---AJS

[CarlB]

You're welcome.

 

A summary of fiuctions, alphabetical & by category is at http://ronleigh.info/autolisp/acatalog.htm

 

The reference "alispref.pdf" is quite handy, I'd upload it except it's much larger than allowed at this site, maybe you can find it elsewhere...

[ASMI]

Command: (apply 'min '(4 6 1 8 0.5 12))
0.5

Command: (apply 'max '(4 6 1 8 0.5 12))
12.0

[Andreneves]

The function MAX doesn´t seem to work with a already defined list of reals, eg:

 

Command: !(Setq A '(1.0 1.2 2.1 3.4))

(1.0 1.2 2.1 3.4))

 

Command: !(Max A)

; error: bad argument type: numberp: (1.0 1.2 2.1 3.4)

 

Command: !(Apply 'Max A)

; error: bad argument type: numberp: (1.0 1.2 2.1 3.4)

 

Any sugestion??

[lpseifert]

Worked for me

 

Command: (Setq A '(1.0 1.2 2.1 3.4))

(1.0 1.2 2.1 3.4)

 

Command: (apply 'max a)

3.4

[jammie]

Hey ajs

 

There is no need to use the ! if you are defining a function on the command line

 

Command: !(Setq A '(1.0 1.2 2.1 3.4))

 

Just use as lpseifert has shown

 

Command: (Setq A '(1.0 1.2 2.1 3.4))

(1.0 1.2 2.1 3.4)

 

Command: (apply 'max a)

3.4

[uddfl]

I don't mean to hijack this thread, but (somewhat related) how would I obtain values that are repeated in a list?

 

e.g. (setq list1 (a b b c)) - how do you extract the value of b?

[Andreneves]

Thanks, for help.

 

The function work fine. I had a problem, because my list has a 'nil' element.

[Lee Mac]

I don't mean to hijack this thread, but (somewhat related) how would I obtain values that are repeated in a list?

 

e.g. (setq list1 (a b b c)) - how do you extract the value of b?

 

I'm not sure if there is a straight-forward function to detect this... I would be inclined to make a comparison between every item in the list and make a list of items already "viewed".

[Lee Mac]

Perhaps something like this:

 

(defun getrep (alist)
 (foreach x alist
   (if (member x nlist)
     (setq dlist (cons x dlist))
     (setq nlist (cons x nlist))))
 dlist)

(defun c:test ()
 (alert (vl-princ-to-string (getrep '(a b c c d e f f g))))
 (princ))

[taner]

another way:

(eval(cons 'max a))

(eval(cons 'min a))

[BIGAL]

If you sort the list then items the same will be next to each other so you can do things like count them up or delete duplicates.