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Diffstat (limited to 'spec/ruby/library/matrix/diagonal_spec.rb')
-rw-r--r-- | spec/ruby/library/matrix/diagonal_spec.rb | 72 |
1 files changed, 72 insertions, 0 deletions
diff --git a/spec/ruby/library/matrix/diagonal_spec.rb b/spec/ruby/library/matrix/diagonal_spec.rb new file mode 100644 index 0000000000..c88a92b5cd --- /dev/null +++ b/spec/ruby/library/matrix/diagonal_spec.rb @@ -0,0 +1,72 @@ +require File.expand_path('../../../spec_helper', __FILE__) +require File.expand_path('../fixtures/classes', __FILE__) +require 'matrix' + +describe "Matrix.diagonal" do + before :each do + @m = Matrix.diagonal(10, 11, 12, 13, 14) + end + + it "returns an object of type Matrix" do + @m.should be_kind_of(Matrix) + end + + it "returns a square Matrix of the right size" do + @m.column_size.should == 5 + @m.row_size.should == 5 + end + + it "sets the diagonal to the arguments" do + (0..4).each do |i| + @m[i, i].should == i + 10 + end + end + + it "fills all non-diagonal cells with 0" do + (0..4).each do |i| + (0..4).each do |j| + if i != j + @m[i, j].should == 0 + end + end + end + end + + describe "for a subclass of Matrix" do + it "returns an instance of that subclass" do + MatrixSub.diagonal(1).should be_an_instance_of(MatrixSub) + end + end +end + +describe "Matrix.diagonal?" do + it "returns true for a diagonal Matrix" do + Matrix.diagonal([1, 2, 3]).diagonal?.should be_true + end + + it "returns true for a zero square Matrix" do + Matrix.zero(3).diagonal?.should be_true + end + + it "returns false for a non diagonal square Matrix" do + Matrix[[0, 1], [0, 0]].diagonal?.should be_false + Matrix[[1, 2, 3], [1, 2, 3], [1, 2, 3]].diagonal?.should be_false + end + + it "returns true for an empty 0x0 matrix" do + Matrix.empty(0,0).diagonal?.should be_true + end + + it "raises an error for rectangular matrices" do + [ + Matrix[[0], [0]], + Matrix[[0, 0]], + Matrix.empty(0, 2), + Matrix.empty(2, 0), + ].each do |rectangual_matrix| + lambda { + rectangual_matrix.diagonal? + }.should raise_error(Matrix::ErrDimensionMismatch) + end + end +end |