Re: Fast List-Selection
- To: mathgroup at smc.vnet.net
- Subject: [mg19899] Re: [mg19880] Fast List-Selection
- From: Rob Pratt <rpratt at email.unc.edu>
- Date: Mon, 20 Sep 1999 20:42:24 -0400
- Sender: owner-wri-mathgroup at wolfram.com
Flatten[Position[Partition[s,7,1],Table[x_,{7}]]]
> I have a list 's' composed of a large number of (small) integers. I wish to
> search this list for instances of 7 consecutive, identical elements.
>
> My approach is:
>
> Do[If[Count[t = Take[s, {i, i + 6}], t[[1]]] == 7,
> Print[i]], {i, 1, Length[s] - 6}]
>
> Can anyone think of a *faster* way of doing this?
Rob Pratt
Department of Operations Research
The University of North Carolina at Chapel Hill
rpratt at email.unc.edu
http://www.unc.edu/~rpratt/