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Diffstat (limited to 'spec/rubyspec/core/math/gamma_spec.rb')
-rw-r--r-- | spec/rubyspec/core/math/gamma_spec.rb | 69 |
1 files changed, 0 insertions, 69 deletions
diff --git a/spec/rubyspec/core/math/gamma_spec.rb b/spec/rubyspec/core/math/gamma_spec.rb deleted file mode 100644 index eb26f25bfe..0000000000 --- a/spec/rubyspec/core/math/gamma_spec.rb +++ /dev/null @@ -1,69 +0,0 @@ -require File.expand_path('../../../spec_helper', __FILE__) - -describe "Math.gamma" do - it "returns +infinity given 0" do - Math.gamma(0).should == Float::INFINITY - end - - platform_is_not :windows do - # https://bugs.ruby-lang.org/issues/12249 - it "returns -infinity given -0.0" do - Math.gamma(-0.0).should == -Float::INFINITY - end - end - - it "returns Math.sqrt(Math::PI) given 0.5" do - Math.gamma(0.5).should be_close(Math.sqrt(Math::PI), TOLERANCE) - end - - # stop at n == 23 because 23! cannot be exactly represented by IEEE 754 double - it "returns exactly (n-1)! given n for n between 2 and 23" do - fact = 1 - 2.upto(23) do |n| - fact *= (n - 1) - Math.gamma(n).should == fact - end - end - - it "returns approximately (n-1)! given n for n between 24 and 30" do - fact2 = 1124000727777607680000 # 22! - 24.upto(30) do |n| - fact2 *= n - 1 - # compare only the first 12 places, tolerate the rest - Math.gamma(n).should be_close(fact2, fact2.to_s[12..-1].to_i) - end - end - - it "returns good numerical approximation for gamma(3.2)" do - Math.gamma(3.2).should be_close(2.423965, TOLERANCE) - end - - it "returns good numerical approximation for gamma(-2.15)" do - Math.gamma(-2.15).should be_close(-2.999619, TOLERANCE) - end - - it "returns good numerical approximation for gamma(0.00001)" do - Math.gamma(0.00001).should be_close(99999.422794, TOLERANCE) - end - - it "returns good numerical approximation for gamma(-0.00001)" do - Math.gamma(-0.00001).should be_close(-100000.577225, TOLERANCE) - end - - it "raises Math::DomainError given -1" do - lambda { Math.gamma(-1) }.should raise_error(Math::DomainError) - end - - # See https://bugs.ruby-lang.org/issues/10642 - it "returns +infinity given +infinity" do - Math.gamma(infinity_value).infinite?.should == 1 - end - - it "raises Math::DomainError given negative infinity" do - lambda { Math.gamma(-Float::INFINITY) }.should raise_error(Math::DomainError) - end - - it "returns NaN given NaN" do - Math.gamma(nan_value).nan?.should be_true - end -end |