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RE: Q: Extract Elements from a List?

• To: mathgroup at smc.vnet.net
• Subject: [mg28982] RE: [mg28968] Q: Extract Elements from a List?
• From: "Higinio Ramos" <higra at gugu.usal.es>
• Date: Thu, 24 May 2001 04:06:59 -0400 (EDT)
• References: <200105230554.BAA01361@smc.vnet.net>
• Sender: owner-wri-mathgroup at wolfram.com

----- Original Message ----- 
From: Robert Schuerhuber <robert.schuerhuber at gmx.at>
To: mathgroup at smc.vnet.net
Subject: [mg28982] [mg28968] Q: Extract Elements from a List?


> 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

This may be done with Take:
takeList[list_, n_, s_] := Take[list, {n, Length[list], s}]
In[22]:=
    takeList[list, 3, 2]
Out[22]=
    {c, e, g, i}

Higinio

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