bootstrapping an array.

replicant4 has asked for the wisdom of the Perl Monks concerning the following question:

hi to all . I have a qustion which might sound easy. I have an array called (@sites) which contains in $sites object. I compare it with another array, and get a certain number of values. Because I want to test the significance of my results, I need to shuffle my @sites, a number of times (say n number) in order to generate random sets of data. that means to change the position of $sites within @sites. How can I do that ? Thanks in advance for everyone's help .

Comment on bootstrapping an array.

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Re: bootstrapping an array. by davido (Cardinal) on Oct 22, 2004 at 15:26 UTC
You want a Fisher-Yates shuffle. It is also found as part of the List::Util module. I'm sure if you Super Search the Monastery you'll find it spelled out here too. For the highest degree of randomness, you just shuffle the list once. This shuffle isn't like shuffling a deck of cards, where you have to do it three or more times to get randomness. The only time you would shuffle more than once is if you have already used the shuffled list, and now need a newly randomized list. Dave	[reply]
Re: bootstrapping an array. by Mutant (Priest) on Oct 22, 2004 at 14:21 UTC
This may be of use...	[reply]
Re: bootstrapping an array. by pelagic (Priest) on Oct 22, 2004 at 14:23 UTC
use Algorithm::Numerical::Shuffle by Abigail ... but right now CPAN seems to be down :( pelagic	[reply]
Re^2: bootstrapping an array. by Happy-the-monk (Canon) on Oct 22, 2004 at 16:22 UTC
CPAN seems to be down :( CPAN is a network and can't just be down. Pick any mirror there. CPAN search is still available, although not at the usual address(es). Cheers, Sören	[reply]