Topic: My head hurts.. problem with a list

[Lee Mac]

Another:

Code: [Select]

(defun _sum ( l )
  (if (cadr l)
    (cons (car l) (_sum (cons (+ (car l) (cadr l)) (cddr l))))
    (list (car l))
  )
)

[gile]

Another, using gc:scan as defined here.

EDIT: rewrited gc:scan function so that the first argument is a 'quoted' function (as others 'high order' AutoLISP functions)

Code: [Select]

(defun gc:scan (fun acc lst)
  (cons acc (mapcar (function (lambda (x) (setq acc ((eval fun) acc x)))) lst))
)

(gc:scan '+ (car lst) (cdr lst))
F#

Code: [Select]

List.scan (+) lst.Head lst.Tail

[Brick_top]

Thanks a lot for all the options!

I have a lot to study

[Brick_top]

Here's one way to do it:

Code: [Select]

(setq lst '(10.2757 12.1581 33.2103 45.11 1.1 2.2 3.3))
(cons (car lst) (mapcar (function (lambda (l1 l2) (+ l1 l2))) lst (cdr lst)))

;;returns
;;(10.2757 22.4338 45.3684 78.3203 46.21 3.3 5.5)

Hi, I just want to thank you for that last part "lst (cdr lst)" didn't know I could do that and it is helping me a lot in other problems I was having. I'm trying to understand what you can do with lambda and mapcar

[ronjonp]

Here's one way to do it:

Code: [Select]

(setq lst '(10.2757 12.1581 33.2103 45.11 1.1 2.2 3.3))
(cons (car lst) (mapcar (function (lambda (l1 l2) (+ l1 l2))) lst (cdr lst)))

;;returns
;;(10.2757 22.4338 45.3684 78.3203 46.21 3.3 5.5)

Hi, I just want to thank you for that last part "lst (cdr lst)" didn't know I could do that and it is helping me a lot in other problems I was having. I'm trying to understand what you can do with lambda and mapcar

Good deal ... if you have any questions don't hesitate to ask.

[VovKa]

a shortened Ron's

Code: [Select]

(mapcar '+ (cons 0 lst) lst)


[Lee Mac]

EDIT:  Wait a minute... I thought the result was meant to be as in post #5?

[ronjonp]

a shortened Ron's

Code: [Select]

(mapcar '+ (cons 0 lst) lst)


Knew you couldn't resist     .very nice BTW 

[Brick_top]

a shortened Ron's

Code: [Select]

(mapcar '+ (cons 0 lst) lst)


Is this for real?     

Don't have autocad right now

[Brick_top]

EDIT:  Wait a minute... I thought the result was meant to be as in post #5?

yeah, it is as in post #5

btw, thanks for your solution but it is way over my head as of now as is gile's

[ronjonp]

a shortened Ron's

Code: [Select]

(mapcar '+ (cons 0 lst) lst)


Is this for real?     

Don't have autocad right now

That gives the same result as my "wrong" answer ... but nonetheless cool. 

[Lee Mac]

EDIT:  Wait a minute... I thought the result was meant to be as in post #5?

yeah, it is as in post #5

Nope...

Code: [Select]

_$ (mapcar '+ (cons 0 '(10 20 30 40 50)) '(10 20 30 40 50))
(10 30 50 70 90)
From your description in post#5, correct result should be:

Code: [Select]

(10 30 60 100 150)

[Guitar_Jones]

Another

Code: [Select]

(defun _sum (l)(mapcar '(lambda (x) (apply '+ (member x (reverse l)))) l))

[Lee Mac]

Another

Code: [Select]

(defun _sum (l)(mapcar '(lambda (x) (apply '+ (member x (reverse l)))) l))

Nice idea, but be careful for duplicate elements! 

[Guitar_Jones]

Thanks Lee. :ugly: