From: Stefan Rusterholz <apeiros@...>
Date: 2007-10-30T08:25:51+09:00
Subject: Re: find the closest items in an array to a given value.

Stefan Rusterholz wrote:
> trebor777 wrote:
>> Hi!
>> 
>> I'm searching for a light method for finding the closest items to a 
>> given
>> value.
> 
> [1,2,3,4,5,6].min { |a,b| (a-value).abs <=> (b-value).abs }
> 
> Regards
> Stefan

Since you want more than 1 you can either implement your own min method 
that returns the 2 smallest ones, that'd happen in O(n), or you can sort 
by the distance, which is O(nlogn):
ary.sort_by { |item| (value-item).abs }.first(n)
If you just want all values that are a max difference of x from y, you 
can use:
ary.select { |item| item - x <= y }

Regards
Stefan
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