require(File.expand_path(File.dirname(__FILE__)+'/helpers_tests.rb'))


class StatsampleHistogramTestCase < MiniTest::Unit::TestCase
  context Statsample::Histogram do
    should "alloc correctly with integer" do
      h = Statsample::Histogram.alloc(4)
      assert_equal([0.0]*4, h.bin)
      assert_equal([0.0]*5, h.range)
    end
    should "alloc correctly with array" do
      h = Statsample::Histogram.alloc([1, 3, 7, 9, 20])
      assert_equal([0.0]*4, h.bin)
      assert_equal([1,3,7,9,20], h.range)
    end
    should "alloc correctly with integer and min, max array" do
      h = Statsample::Histogram.alloc(5, [0, 5])
      assert_equal([0.0,1.0,2.0,3.0,4.0,5.0], h.range)
      assert_equal([0.0]*5,h.bin)
    end
    should "bin() method return correct number of bins" do
      h = Statsample::Histogram.alloc(4)
      assert_equal(4,h.bins)
    end
    should "increment correctly" do 
      h = Statsample::Histogram.alloc(5, [0, 5])      
      h.increment 2.5
      assert_equal([0.0,0.0,1.0,0.0,0.0], h.bin)
      h.increment [0.5,0.5,3.5,3.5]
      assert_equal([2.0,0.0,1.0,2.0,0.0], h.bin)
      h.increment 0
      assert_equal([3.0,0.0,1.0,2.0,0.0], h.bin)
      h.increment 5
      assert_equal([3.0,0.0,1.0,2.0,0.0], h.bin)
    end
    
    should "alloc_uniform correctly with n, min,max" do
      h = Statsample::Histogram.alloc_uniform(5,0,10)
      assert_equal(5,h.bins)
      assert_equal([0.0]*5,h.bin)
      assert_equal([0.0,2.0,4.0,6.0,8.0,10.0], h.range)
    end
    should "alloc_uniform correctly with n, [min,max]" do
      h = Statsample::Histogram.alloc_uniform(5, [0, 10])
      assert_equal(5,h.bins)
      assert_equal([0.0]*5,h.bin)
      assert_equal([0.0,2.0,4.0,6.0,8.0,10.0], h.range)
    end
    should "get_range()" do
      h = Statsample::Histogram.alloc_uniform(5,2,12)
      5.times {|i|
        assert_equal([2+i*2, 4+i*2], h.get_range(i))
      }
    end
    should "min() and max()" do
      h=Statsample::Histogram.alloc_uniform(5,2,12)
      assert_equal(2,h.min)
      assert_equal(12,h.max)
    end
    should "max_val()" do
       h = Statsample::Histogram.alloc(5, [0, 5])
       100.times {h.increment(rand*5)}
       max=h.bin[0]
       (1..4).each {|i|
         max = h.bin[i] if h.bin[i] > max
       }
       assert_equal(max,h.max_val)
    end
    should "min_val()" do
       h = Statsample::Histogram.alloc(5, [0, 5])
       100.times {h.increment(rand*5)}
       min=h.bin[0]
       (1..4).each {|i|
         min = h.bin[i] if h.bin[i]<min
       }
       assert_equal(min,h.min_val)
    end
    should "return correct estimated mean" do
      a=[1.5,1.5,1.5,3.5,3.5,3.5].to_scale
      h=Statsample::Histogram.alloc(5,[0,5])
      h.increment(a)
      assert_equal(2.5, h.estimated_mean)
    end
    should "return correct estimated standard deviation" do
      a=[0.5,1.5,1.5,1.5,2.5, 3.5,3.5,3.5,4.5].to_scale
      h=Statsample::Histogram.alloc(5,[0,5])
      h.increment(a)
      assert_equal(a.sd, h.estimated_standard_deviation)
    end
    should "return correct sum for all values" do
      h=Statsample::Histogram.alloc(5,[0,5])
      n=rand(100)
      n.times { h.increment(1)}
      assert_equal(n, h.sum)
    end
    should "return correct sum for a subset of values" do
      h=Statsample::Histogram.alloc(5,[0,5])
      h.increment([0.5,2.5,4.5])
      assert_equal(1,h.sum(0,1))
      assert_equal(2,h.sum(1,4))

    end
    
  end
end