diff options
| -rw-r--r-- | lib/matrix.rb | 29 | ||||
| -rw-r--r-- | test/matrix/test_matrix.rb | 17 |
2 files changed, 46 insertions, 0 deletions
diff --git a/lib/matrix.rb b/lib/matrix.rb index 0a2b609b59..2f2d0f371a 100644 --- a/lib/matrix.rb +++ b/lib/matrix.rb @@ -250,6 +250,35 @@ class Matrix end # + # Create a matrix by combining matrices entrywise, using the given block + # + # x = Matrix[[6, 6], [4, 4]] + # y = Matrix[[1, 2], [3, 4]] + # Matrix.combine(x, y) {|a, b| a - b} # => Matrix[[5, 4], [1, 2]] + # + def Matrix.combine(*matrices) + return to_enum(__method__, *matrices) unless block_given? + + return Matrix.empty if matrices.empty? + matrices.map!(&CoercionHelper.method(:coerce_to_matrix)) + x = matrices.first + matrices.each do |m| + Matrix.Raise ErrDimensionMismatch unless x.row_count == m.row_count && x.column_count == m.column_count + end + + rows = Array.new(x.row_count) do |i| + Array.new(x.column_count) do |j| + yield matrices.map{|m| m[i,j]} + end + end + new rows, x.column_count + end + + def combine(*matrices, &block) + Matrix.combine(self, *matrices, &block) + end + + # # Matrix.new is private; use Matrix.rows, columns, [], etc... to create. # def initialize(rows, column_count = rows[0].size) diff --git a/test/matrix/test_matrix.rb b/test/matrix/test_matrix.rb index 5b0bc968f7..92a24d1e9f 100644 --- a/test/matrix/test_matrix.rb +++ b/test/matrix/test_matrix.rb @@ -592,6 +592,23 @@ class TestMatrix < Test::Unit::TestCase assert_equal Matrix[[1],[2],[3]], Matrix.vstack(Vector[1,2], Vector[3]) end + def test_combine + x = Matrix[[6, 6], [4, 4]] + y = Matrix[[1, 2], [3, 4]] + assert_equal Matrix[[5, 4], [1, 0]], Matrix.combine(x, y) {|a, b| a - b} + assert_equal Matrix[[5, 4], [1, 0]], x.combine(y) {|a, b| a - b} + # Without block + assert_equal Matrix[[5, 4], [1, 0]], Matrix.combine(x, y).each {|a, b| a - b} + # With vectors + assert_equal Matrix[[111], [222]], Matrix.combine(Matrix[[1], [2]], Vector[10,20], Vector[100,200], &:sum) + # Basic checks + assert_raise(Matrix::ErrDimensionMismatch) { @m1.combine(x) { raise } } + # Edge cases + assert_equal Matrix.empty, Matrix.combine{ raise } + assert_equal Matrix.empty(3,0), Matrix.combine(Matrix.empty(3,0), Matrix.empty(3,0)) { raise } + assert_equal Matrix.empty(0,3), Matrix.combine(Matrix.empty(0,3), Matrix.empty(0,3)) { raise } + end + def test_eigenvalues_and_eigenvectors_symmetric m = Matrix[ [8, 1], |