From: Gavin Kistner <gavin.kistner@...>
Date: 2007-07-07T05:35:48+09:00
Subject: Re: simple question on rbgsl vectors

From: baptiste Augui� [mailto:ba208@exeter.ac.uk] 
Sent: Friday, July 06, 2007 1:57 PM
> Does anybody see this odd behavior:
> 
> irb(main):001:0> require("rbgsl")
> => true
> irb(main):002:0> v = GSL::Vector[0..5]
> => GSL::Vector: [ 0.000e+00 1.000e+00 2.000e+00 3.000e+00 4.000e+00  
> 5.000e+00 ]
> irb(main):003:0> v[2]
> => 2.0
> irb(main):004:0> v[1, 3, 4]
> => GSL::Vector: [ 0.000e+00 1.000e+00 2.000e+00 ]
> 
> **** where is should expect ****
> 
> => GSL::Vector: [ 1.000e+00 3.000e+00 4.000e+00 ]

I've never used GSL, but it looks like it relies on NArray.
It looks like NArray#[] doesn't do what you expect for the above, but (maybe) if you did:
  v[ [1,3,4] ]
you might get the result you desire.