include Stats

describe NormaleDistribution do
  it "between" do
    bet = NormaleDistribution.between standard_deviation: 1, esperance: 0, min: -1, max: 1
    less = NormaleDistribution.less_than standard_deviation: 1, esperance: 0, max: -1
    greater = NormaleDistribution.greater_than standard_deviation: 1, esperance: 0, min: 1
    bet.should eq 1 - less - greater
  end
end

describe NormaleDistribution::Persistant do
  it "instances" do
    NormaleDistribution::Persistant(Float64, Float64).new
    NormaleDistribution::Persistant(Int32, Float64).new(standard_deviation: 12).standard_deviation.should eq(12)
    NormaleDistribution::Persistant(Float64, Int32).new(esperance: 14).esperance.should eq(14)
  end

  it "instances with BigNumber" do
    n = NormaleDistribution::Persistant.new(
      standard_deviation: BigInt.new(1),
      esperance: BigFloat.new(1))
    n.standard_deviation.should eq(1)
    n.esperance.should eq(1)
  end

  it "QI" do
    rule = NormaleDistribution::Persistant.new standard_deviation: 15, esperance: 100
    rule.between(85, 115).round(2).should eq(0.68)
  end

  it "centroid" do
    [0.1, 1.0, 2.0, 4.1324].each do |space|
      [0.0, 1.0, -1.0, 12.0, 41.0, 0.2, 0.233].each do |center|
        rule = NormaleDistribution::Persistant.new standard_deviation: space, esperance: center
        [0.2, 0.4, 0.45, 0.55, 0.94, 1.1].each do |diff|
          (-rule.between(diff, center)).should eq(rule.between(center, diff))
        end
      end
    end
  end

  it "must fail" do
    expect_raises(ArgumentError) { NormaleDistribution::Persistant(Int32, Float64).new standard_deviation: -1 }
    expect_raises(ArgumentError) { NormaleDistribution::Persistant(Int32, Float64).new standard_deviation: 0 }
  end
end