Re: Counting Runs
- To: mathgroup at smc.vnet.net
- Subject: [mg51960] Re: Counting Runs
- From: Peter Pein <petsie at arcor.de>
- Date: Fri, 5 Nov 2004 02:19:44 -0500 (EST)
- References: <cmclmu$i99$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Gregory Lypny wrote:
> Looking for an elegant way to count runs to numbers in a series.
> Suppose I have a list of ones and negative ones such as
> v={1,1,1,-1,1,1,1,1,1,-1,-1,-1,-1,1}.
> I'd like to create a function that counts the number of runs of 1s and
> -1s, which in this case is 3 and 2.
>
> Greg
>
Please forgive me. First I had another way to solve your problem in
mind. Of course it's sufficient to define
countruns[data_, items_] :=
Count[Split[data], {x__} /; x == #] & /@ items
--
Peter Pein
Berlin