From: 7stud -- <bbxx789_05ss@...>
Date: 2011-05-15T06:36:28+09:00
Subject: Re: search nearest to elements in array (hash)

7stud -- wrote in post #998723:
> data = [1.1, 4.2, 3.1, 2.6, 6.1, 5.0]
> needle = rand 10
>
> arr = data.map do |num|
>    [(num - needle).abs, num]
> end
>
> sorted = arr.sort_by {|sub_arr| sub_arr[0]}
>
> puts needle
> puts sorted.first[1]
>
> --output:--
> 2
> 2.6

And...if you want a ranking of the differences, add one more map():

data = [1.1, 4.2, 3.1, 2.6, 6.1, 5.0]
needle = rand 10

arr = data.map do |num|
   [(num - needle).abs, num]
end

sorted = arr.sort_by {|sub_arr| sub_arr[0]}
rankings = sorted.map {|sub_arr| sub_arr[1]}

puts needle
p sorted
puts sorted.first[1]
p rankings

--output:--
2
[[0.6000000000000001, 2.6], [0.8999999999999999, 1.1], [1.1, 3.1], [2.2, 
4.2], [3.0, 5.0], [4.1, 6.1]]
2.6
[2.6, 1.1, 3.1, 4.2, 5.0, 6.1]

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