Add in-tree mspec and ruby/spec

* For easier modifications of ruby/spec by MRI developers.
* .gitignore: track changes under spec.
* spec/mspec, spec/rubyspec: add in-tree mspec and ruby/spec.
  These files can therefore be updated like any other file in MRI.
  Instructions are provided in spec/README.
  [Feature #13156] [ruby-core:79246]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@58595 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

7 files changed, 174 insertions, 0 deletions

diff --git a/spec/rubyspec/library/matrix/lup_decomposition/determinant_spec.rb b/spec/rubyspec/library/matrix/lup_decomposition/determinant_spec.rb
new file mode 100644
index 0000000000..f73c65ba8f
--- /dev/null
+++ b/spec/rubyspec/library/matrix/lup_decomposition/determinant_spec.rb
@@ -0,0 +1,21 @@
+require File.expand_path('../../../../spec_helper', __FILE__)
+require 'matrix'
+
+describe "Matrix::LUPDecomposition#determinant" do
+  it "returns the determinant when the matrix is square" do
+    a = Matrix[[7, 8, 9], [14, 46, 51], [28, 82, 163]]
+    a.lup.determinant.should == 15120 # == a.determinant
+  end
+
+  it "raises an error for rectangular matrices" do
+    [
+      Matrix[[7, 8, 9], [14, 46, 51]],
+      Matrix[[7, 8], [14, 46], [28, 82]],
+    ].each do |m|
+      lup = m.lup
+      lambda {
+        lup.determinant
+      }.should raise_error(Matrix::ErrDimensionMismatch)
+    end
+  end
+end
diff --git a/spec/rubyspec/library/matrix/lup_decomposition/initialize_spec.rb b/spec/rubyspec/library/matrix/lup_decomposition/initialize_spec.rb
new file mode 100644
index 0000000000..953389083f
--- /dev/null
+++ b/spec/rubyspec/library/matrix/lup_decomposition/initialize_spec.rb
@@ -0,0 +1,13 @@
+require File.expand_path('../../../../spec_helper', __FILE__)
+require 'matrix'
+
+describe "Matrix::LUPDecomposition#initialize" do
+  it "raises an error if argument is not a matrix" do
+    lambda {
+      Matrix::LUPDecomposition.new([[]])
+    }.should raise_error(TypeError)
+    lambda {
+      Matrix::LUPDecomposition.new(42)
+    }.should raise_error(TypeError)
+  end
+end
diff --git a/spec/rubyspec/library/matrix/lup_decomposition/l_spec.rb b/spec/rubyspec/library/matrix/lup_decomposition/l_spec.rb
new file mode 100644
index 0000000000..c50b5f712e
--- /dev/null
+++ b/spec/rubyspec/library/matrix/lup_decomposition/l_spec.rb
@@ -0,0 +1,18 @@
+require File.expand_path('../../../../spec_helper', __FILE__)
+require 'matrix'
+
+describe "Matrix::LUPDecomposition#l" do
+  before :each do
+    @a = Matrix[[7, 8, 9], [14, 46, 51], [28, 82, 163]]
+    @lu = Matrix::LUPDecomposition.new(@a)
+    @l = @lu.l
+  end
+
+  it "returns the first element of to_a" do
+    @l.should == @lu.to_a[0]
+  end
+
+  it "returns a lower triangular matrix" do
+    @l.lower_triangular?.should be_true
+  end
+end
diff --git a/spec/rubyspec/library/matrix/lup_decomposition/p_spec.rb b/spec/rubyspec/library/matrix/lup_decomposition/p_spec.rb
new file mode 100644
index 0000000000..837b65a915
--- /dev/null
+++ b/spec/rubyspec/library/matrix/lup_decomposition/p_spec.rb
@@ -0,0 +1,18 @@
+require File.expand_path('../../../../spec_helper', __FILE__)
+require 'matrix'
+
+describe "Matrix::LUPDecomposition#p" do
+  before :each do
+    @a = Matrix[[7, 8, 9], [14, 46, 51], [28, 82, 163]]
+    @lu = Matrix::LUPDecomposition.new(@a)
+    @p = @lu.p
+  end
+
+  it "returns the third element of to_a" do
+    @p.should == @lu.to_a[2]
+  end
+
+  it "returns a permutation matrix" do
+    @p.permutation?.should be_true
+  end
+end
diff --git a/spec/rubyspec/library/matrix/lup_decomposition/solve_spec.rb b/spec/rubyspec/library/matrix/lup_decomposition/solve_spec.rb
new file mode 100644
index 0000000000..c4ef42bcea
--- /dev/null
+++ b/spec/rubyspec/library/matrix/lup_decomposition/solve_spec.rb
@@ -0,0 +1,53 @@
+require File.expand_path('../../../../spec_helper', __FILE__)
+require 'matrix'
+
+describe "Matrix::LUPDecomposition#solve" do
+  describe "for rectangular matrices" do
+    it "raises an error for singular matrices" do
+      a = Matrix[[1, 2, 3], [1, 3, 5], [2, 5, 8]]
+      lu = Matrix::LUPDecomposition.new(a)
+      lambda {
+        lu.solve(a)
+      }.should raise_error(Matrix::ErrNotRegular)
+    end
+
+    describe "for non singular matrices" do
+      before :each do
+        @a = Matrix[[7, 8, 9], [14, 46, 51], [28, 82, 163]]
+        @lu = Matrix::LUPDecomposition.new(@a)
+      end
+
+      it "returns the appropriate empty matrix when given an empty matrix" do
+        @lu.solve(Matrix.empty(3,0)).should == Matrix.empty(3,0)
+        empty = Matrix::LUPDecomposition.new(Matrix.empty(0, 0))
+        empty.solve(Matrix.empty(0,3)).should == Matrix.empty(0,3)
+      end
+
+      it "returns the right matrix when given a matrix of the appropriate size" do
+        solution = Matrix[[1, 2, 3, 4], [0, 1, 2, 3], [-1, -2, -3, -4]]
+        values = Matrix[[-2, 4, 10, 16], [-37, -28, -19, -10], [-135, -188, -241, -294]] # == @a * solution
+        @lu.solve(values).should == solution
+      end
+
+      it "raises an error when given a matrix of the wrong size" do
+        values = Matrix[[1, 2, 3, 4], [0, 1, 2, 3]]
+        lambda {
+          @lu.solve(values)
+        }.should raise_error(Matrix::ErrDimensionMismatch)
+      end
+
+      it "returns the right vector when given a vector of the appropriate size" do
+        solution = Vector[1, 2, -1]
+        values = Vector[14, 55, 29] # == @a * solution
+        @lu.solve(values).should == solution
+      end
+
+      it "raises an error when given a vector of the wrong size" do
+        values = Vector[14, 55]
+        lambda {
+          @lu.solve(values)
+        }.should raise_error(Matrix::ErrDimensionMismatch)
+      end
+    end
+  end
+end
diff --git a/spec/rubyspec/library/matrix/lup_decomposition/to_a_spec.rb b/spec/rubyspec/library/matrix/lup_decomposition/to_a_spec.rb
new file mode 100644
index 0000000000..20be26eb9c
--- /dev/null
+++ b/spec/rubyspec/library/matrix/lup_decomposition/to_a_spec.rb
@@ -0,0 +1,33 @@
+require File.expand_path('../../../../spec_helper', __FILE__)
+require 'matrix'
+
+describe "Matrix::LUPDecomposition#to_a" do
+  before :each do
+    @a = Matrix[[7, 8, 9], [14, 46, 51], [28, 82, 163]]
+    @lu = Matrix::LUPDecomposition.new(@a)
+    @to_a = @lu.to_a
+    @l, @u, @p = @to_a
+  end
+
+  it "returns an array of three matrices" do
+    @to_a.should be_kind_of(Array)
+    @to_a.length.should == 3
+    @to_a.each{|m| m.should be_kind_of(Matrix)}
+  end
+
+  it "returns [l, u, p] such that l*u == a*p" do
+    (@l * @u).should == (@p * @a)
+  end
+
+  it "returns the right values for rectangular matrices" do
+    [
+      Matrix[[7, 8, 9], [14, 46, 51]],
+      Matrix[[4, 11], [5, 8], [3, 4]],
+    ].each do |a|
+      l, u, p = Matrix::LUPDecomposition.new(a).to_a
+      (l * u).should == (p * a)
+    end
+  end
+
+  it "has other properties implied by the specs of #l, #u and #p"
+end
diff --git a/spec/rubyspec/library/matrix/lup_decomposition/u_spec.rb b/spec/rubyspec/library/matrix/lup_decomposition/u_spec.rb
new file mode 100644
index 0000000000..97e8580c58
--- /dev/null
+++ b/spec/rubyspec/library/matrix/lup_decomposition/u_spec.rb
@@ -0,0 +1,18 @@
+require File.expand_path('../../../../spec_helper', __FILE__)
+require 'matrix'
+
+describe "Matrix::LUPDecomposition#u" do
+  before :each do
+    @a = Matrix[[7, 8, 9], [14, 46, 51], [28, 82, 163]]
+    @lu = Matrix::LUPDecomposition.new(@a)
+    @u = @lu.u
+  end
+
+  it "returns the second element of to_a" do
+    @u.should == @lu.to_a[1]
+  end
+
+  it "returns an upper triangular matrix" do
+    @u.upper_triangular?.should be_true
+  end
+end