# Re: neuroimage software - scientific computing and visualiza

**URL:** <https://www.ruby-forum.com/t/re-neuroimage-software-scientific-computing-and-visualiza/100510>\
**Category:** Ruby\
**Created:** [February 3, 2006, 2:19am UTC](https://www.ruby-forum.com/t/re-neuroimage-software-scientific-computing-and-visualiza/100510 "2006-02-03T02:19:57Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![dasch](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/d/b2d939/32.png) [@dasch](https://www.ruby-forum.com/u/dasch)\
**Post date:** [February 3, 2006, 2:19am UTC](https://www.ruby-forum.com/t/re-neuroimage-software-scientific-computing-and-visualiza/100510/1 "2006-02-03T02:19:57Z")

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> So are you saying that if you have an array like:  
> a = [‘d’, ‘b’, ‘a’, ‘c’, ‘e’]  
> You would like to get something like:  
> a.sort\_index #=\> [2, 1, 3, 0, 4]
> 
> If that’s the case, then I’m sure it’s doable. No built-in  
> method that I’m  
> aware of, but you could easily create one.

For example:

class Array  
def sort\_index  
(0…size).sort\_by {|i| self[i]}  
end  
end

%w{d b a c e}.sort\_index  
=\> [2, 1, 3, 0, 4]