From: Sergey Volkov <gm.vlkv@...>
Date: 2006-05-06T03:45:54+09:00
Subject: Re: Finding an interval in a sorted array?

class Array
    def interval_containing( x )
        # elegant code goes here
        [select{|e|e<=x}[-1], select{|e|e>=x}[0]].compact.uniq
    end
end

% ruby tIntervalContaining.rb
Loaded suite tIntervalContaining
Started
.
Finished in 0.0 seconds.

1 tests, 7 assertions, 0 failures, 0 errors
---------

best
Sergey

----- Original Message ----- 
From: "Bil Kleb" <Bil.Kleb@nasa.gov>
To: "ruby-talk ML" <ruby-talk@ruby-lang.org>
Sent: Friday, May 05, 2006 1:25 PM
Subject: Finding an interval in a sorted array?


> Hello,
> 
> Surely there is a way to find an interval in a sorted array
> without resorting to indices?  (I'm drawing a blank.)
> 
>  require 'test/unit'
> 
>  class Array
>    def interval_containing( x )
>      # elegant code goes here
>    end
>  end
> 
>  class TestIntervalFinder < Test::Unit::TestCase
>    def test_finds_intervals
>      data = [ 0, 1, 2 ].sort
>      assert_equal [0],   data.interval_containing(-0.2)
>      assert_equal [0],   data.interval_containing( 0.0)
>      assert_equal [0,1], data.interval_containing( 0.5)
>      assert_equal [1],   data.interval_containing( 1.0)
>      assert_equal [1,2], data.interval_containing( 1.6)
>      assert_equal [2],   data.interval_containing( 2.0)
>      assert_equal [2],   data.interval_containing( 5.0)
>    end
>  end
> 
> Thanks,
> -- 
> Bil
> http://fun3d.larc.nasa.gov
>