List transformation

[Browning_Zed]

Hi all.
I need help changing the list. The original list has the following format:
'((2.1 3.5 0.0) (10.9 11.2 3.6) (12.4 19.7 5.5))
it needs to be converted to a list of this format:
'(2.1 3.5 10.9 11.2 12.4 19.7)
that is, in the original list should remove the third item of each sublist, and transform the original list from a nested list to a simple list. In other words, the elements of the original list marked in red must be deleted.

[hak_vz · Accepted solution]

(defun take (amount lst / ret)(repeat amount (setq ret (cons (car lst) (take (1- amount) (cdr lst))))))
(defun take2 (lst) (take 2 lst))
(apply 'append(mapcar 'take2 '((2.1 3.5 0.0) (10.9 11.2 3.6) (12.4 19.7 5.5))))

(2.1 3.5 10.9 11.2 12.4 19.7)

@Browning_Zed 

I guess you've received this functions before. It's time to start using them.

[-didier- · Accepted solution]

Bonjour @Browning_Zed 

Here is my proposal to do this task

Amicalement

(apply 'append (mapcar (function (lambda (x) (reverse (cdr (reverse x))))) l1))

[Browning_Zed]

Thanks for the help. What function are we talking about?

[Browning_Zed]

Thank you very much.

[hak_vz]

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@Browning_Zed wrote:

Thanks for the help. What function are we talking about?

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Function take, I use it regularly in my codes, and variations with apply mapcar. 

[Browning_Zed]

Got it, thanks.