Re: Challenge: Fastest method to convert positive integers to 1 in a long list

*To*: mathgroup at smc.vnet.net*Subject*: [mg52174] Re: [mg52172] Challenge: Fastest method to convert positive integers to 1 in a long list*From*: Andrzej Kozlowski <akoz at mimuw.edu.pl>*Date*: Sun, 14 Nov 2004 04:30:10 -0500 (EST)*References*: <200411130940.EAA01037@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

On 13 Nov 2004, at 18:40, Carl K. Woll wrote: > Hi all, > > Inspired by the recent thread on counting runs, I have the following > challenge. Come up with a method to convert all the positive integers > in a > long sequence of nonnegative integers to 1, so that the sequence > consists of > only 0s and 1s. Let the sequence be given by > > seq = Table[Random[Integer, 10], {10^6}]; > > Then, one technique is > > newseq = 1+Quotient[#,#+1,1]&@seq; > > Can anyone do better? > > Carl Woll > > > This seems to be very much faster: newseq = Sign[seq]; Andrzej Kozlowski Chiba, Japan http://www.akikoz.net/~andrzej/ http://www.mimuw.edu.pl/~akoz/

**References**:**Challenge: Fastest method to convert positive integers to 1 in a long list***From:*"Carl K. Woll" <carlw@u.washington.edu>