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MathGroup Archive 2004

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

  • To: mathgroup at smc.vnet.net
  • Subject: [mg52198] Re: Challenge: Fastest method to convert positive integers to 1 in a long list
  • From: "Peltio" <peltio at twilight.zone>
  • Date: Sun, 14 Nov 2004 04:31:10 -0500 (EST)
  • References: <cn4m4e$19p$1@smc.vnet.net>
  • Reply-to: "Peltio" <peltioNOSP at Mdespammed.com.invalid>
  • Sender: owner-wri-mathgroup at wolfram.com

"Carl K. Woll" wrote


>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?

Can't test it right now, but how about

newseq = Sign@seq;

?
cheers,
Peltio




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