require File.expand_path(File.dirname(__FILE__) + '/spec_helper.rb') include ExampleWithGSL describe Distribution::T do shared_examples_for 'T engine(with rng)' do it 'should return correct rng' do pending end end shared_examples_for 'T engine(cdf with fractional df)' do it 'should return correct cdf with fractional df' do expect(@engine.cdf(1, 2.5)).to be_within(1e-6).of(0.7979695) expect(@engine.cdf(2, 3.5)).to be_within(1e-6).of(0.9369307) expect(@engine.cdf(3, 4.5)).to be_within(1e-6).of(0.9828096) end end shared_examples_for 'T engine' do it_only_with_gsl 'should return correct pdf' do if @engine.respond_to? :pdf [-2, 0.1, 0.5, 1, 2].each{|t| [2, 5, 10].each{|n| expect(@engine.pdf(t, n)).to be_within(1e-6).of(GSL::Ran.tdist_pdf(t, n)) expect(@engine.pdf(t, n.to_f)).to be_within(1e-6).of(@engine.pdf(t, n)) } } else pending("No #{@engine}.pdf") end end it_only_with_gsl 'should return correct cdf' do if @engine.respond_to? :cdf # Testing with R values expect(@engine.cdf(1, 2)).to be_within(1e-7).of(0.7886751) expect(@engine.cdf(1, 2.0)).to be_within(1e-7).of(0.7886751) expect(@engine.cdf(1, 3.0)).to be_within(1e-7).of(0.8044989) [-2, 0.1, 0.5, 1, 2].each{|t| [2, 5, 10].each{|n| expect(@engine.cdf(t, n)).to be_within(1e-4).of(GSL::Cdf.tdist_P(t, n)) expect(@engine.cdf(t, n)).to be_within(1e-4).of(@engine.cdf(t, n.to_f)) } } else pending("No #{@engine}.cdf") end end it_only_with_gsl 'should return correct p_value' do if @engine.respond_to? :p_value [-2, 0.1, 0.5, 1, 2].each{|t| [2, 5, 10].each{|n| area = Distribution::T.cdf(t, n) expect(@engine.p_value(area, n)).to be_within(1e-4).of(GSL::Cdf.tdist_Pinv(area, n)) } } else pending("No #{@engine}.p_value") end end end describe 'singleton' do before do @engine = Distribution::T end it_should_behave_like 'T engine' end describe Distribution::T::Ruby_ do before do @engine = Distribution::T::Ruby_ end it_should_behave_like 'T engine' it_should_behave_like 'T engine(cdf with fractional df)' end if Distribution.has_gsl? describe Distribution::T::GSL_ do before do @engine = Distribution::T::GSL_ end it_should_behave_like 'T engine' it_should_behave_like 'T engine(cdf with fractional df)' end end if Distribution.has_java? describe Distribution::T::Java_ do before do @engine = Distribution::T::Java_ end it_should_behave_like 'T engine' end end end