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Diffstat (limited to 'spec/rubyspec/core/math/erfc_spec.rb')
-rw-r--r-- | spec/rubyspec/core/math/erfc_spec.rb | 43 |
1 files changed, 43 insertions, 0 deletions
diff --git a/spec/rubyspec/core/math/erfc_spec.rb b/spec/rubyspec/core/math/erfc_spec.rb new file mode 100644 index 0000000000..21c9e246ff --- /dev/null +++ b/spec/rubyspec/core/math/erfc_spec.rb @@ -0,0 +1,43 @@ +require File.expand_path('../../../spec_helper', __FILE__) +require File.expand_path('../fixtures/classes', __FILE__) + +# erfc is the complementary error function +describe "Math.erfc" do + it "returns a float" do + Math.erf(1).should be_kind_of(Float) + end + + it "returns the complementary error function of the argument" do + Math.erfc(0).should be_close(1.0, TOLERANCE) + Math.erfc(1).should be_close(0.157299207050285, TOLERANCE) + Math.erfc(-1).should be_close(1.84270079294971, TOLERANCE) + Math.erfc(0.5).should be_close(0.479500122186953, TOLERANCE) + Math.erfc(-0.5).should be_close(1.52049987781305, TOLERANCE) + Math.erfc(10000).should be_close(0.0, TOLERANCE) + Math.erfc(-10000).should be_close(2.0, TOLERANCE) + Math.erfc(0.00000000000001).should be_close(0.999999999999989, TOLERANCE) + Math.erfc(-0.00000000000001).should be_close(1.00000000000001, TOLERANCE) + end + + it "raises a TypeError if the argument cannot be coerced with Float()" do + lambda { Math.erfc("test") }.should raise_error(TypeError) + end + + it "returns NaN given NaN" do + Math.erfc(nan_value).nan?.should be_true + end + + it "raises a TypeError if the argument is nil" do + lambda { Math.erfc(nil) }.should raise_error(TypeError) + end + + it "accepts any argument that can be coerced with Float()" do + Math.erfc(MathSpecs::Float.new).should be_close(0.157299207050285, TOLERANCE) + end +end + +describe "Math#erfc" do + it "is accessible as a private instance method" do + IncludesMath.new.send(:erf, 3.1415).should be_close(0.999991118444483, TOLERANCE) + end +end |