From: Bil Kleb <Bil.Kleb@...>
Date: 2006-05-06T02:25:31+09:00
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