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Re: Q: Extract Elements from a List?

• To: mathgroup at smc.vnet.net
• Subject: [mg28978] Re: [mg28968] Q: Extract Elements from a List?
• From: Anesh Sooklal <anesh at fermi.udw.ac.za>
• Date: Thu, 24 May 2001 04:06:55 -0400 (EDT)
• References: <200105230554.BAA01361@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

Dear Robert,

Here is a quick solution

test = {a, b, c, d, e, f, g, h, i, j}
h[a_, d_] := Table[Part[test, n], {n, a, Part[Dimensions[test], 1], d}]

Here a function is designed to give you the list output you desire.
Here a is the first element to be extracted and d is the step size through
the list thereafter.

Let me know how this turns out!!

Thank you,
Anesh


Robert Schuerhuber wrote:

> hi!
>
> probably a very easy question, but i couldn't find an answer in the
> mathematica-book:
>
> i need to extract elements from a list, starting th element number x and
> than taking every yth element, eg:
>
> with
>
> list={a,b,c,d,e,f,g,h,i,j}
> start=3;
> step=2:
>
> i'd like to get the list
>
> {c,e,g,i}.
>
> how can i do this in the easiest way?
>
> regards, robert

• References:
  • Q: Extract Elements from a List?
    • From: Robert Schuerhuber <robert.schuerhuber@gmx.at>