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authoreregon <eregon@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2017-09-20 20:18:52 +0000
committereregon <eregon@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>2017-09-20 20:18:52 +0000
commit1d15d5f08032acf1b7bceacbb450d617ff6e0931 (patch)
treea3785a79899302bc149e4a6e72f624ac27dc1f10 /spec/ruby/library/matrix/exponent_spec.rb
parent75bfc6440d595bf339007f4fb280fd4d743e89c1 (diff)
Move spec/rubyspec to spec/ruby for consistency
* Other ruby implementations use the spec/ruby directory. [Misc #13792] [ruby-core:82287] git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59979 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
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diff --git a/spec/ruby/library/matrix/exponent_spec.rb b/spec/ruby/library/matrix/exponent_spec.rb
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+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../fixtures/classes', __FILE__)
+require 'matrix'
+
+describe "Matrix#**" do
+
+ describe "given an integer _n_" do
+ it "multiples the Matrix by itself _n_ times" do
+ m = Matrix[ [7,6], [3,9] ]
+ (m ** 1).should == m
+ (m ** 2).should == Matrix[ [67, 96], [48,99] ]
+ (m ** 2).should == m * m
+ (m ** 3).should == m * m * m
+ (m ** 4).should == m * m * m * m
+ (m ** 5).should == m * m * m * m * m
+ end
+
+ it "raises a ErrDimensionMismatch for non square matrices" do
+ m = Matrix[ [1, 1], [1, 2], [2, 3]]
+ lambda { m ** 3 }.should raise_error(Matrix::ErrDimensionMismatch)
+ lambda { m ** 0 }.should raise_error(Matrix::ErrDimensionMismatch)
+ end
+
+ describe "that is <= 0" do
+ it "returns the inverse of **(-n)" do
+ m = Matrix[ [1, 1], [1, 2] ]
+ (m ** -2).should == Matrix[ [5, -3], [-3, 2]]
+ (m ** -4).should == (m.inverse ** 4)
+ end
+
+ it "raises a ErrDimensionMismatch for irregular matrices" do
+ m = Matrix[ [1, 1], [1, 1] ]
+ lambda { m ** -2 }.should raise_error(Matrix::ErrNotRegular)
+ lambda { m ** 0 }.should raise_error(Matrix::ErrNotRegular)
+ end
+ end
+ end
+
+ it "returns the power for non integer powers" do
+ a = Matrix[[5, 4], [4, 5]]
+ ((a ** 0.5) ** 2).round(8).should == a
+ a = Matrix[[7, 10], [15, 22]]
+ ((a ** 0.25) ** 4).round(8).should == a
+ end
+
+ describe "for a subclass of Matrix" do
+ it "returns an instance of that subclass" do
+ (MatrixSub.ins ** 1).should be_an_instance_of(MatrixSub)
+ end
+ end
+end