Feature #10056 » add_matrix#adjugate_method.patch
| NEWS | ||
|---|---|---|
|
by deleting the specified row and column.
|
||
|
* Matrix#cofactor(row, column) returns the (row, column) cofactor
|
||
|
which is obtained by multiplying the first minor by (-1)**(row + column).
|
||
|
* Matrix#adjugate returns the adjugate of the matrix.
|
||
|
* Method
|
||
|
* New methods:
|
||
| lib/matrix.rb | ||
|---|---|---|
|
# * #minor(*param)
|
||
|
# * #first_minor(row, column)
|
||
|
# * #cofactor(row, column)
|
||
|
# * #adjugate
|
||
|
#
|
||
|
# Properties of a matrix:
|
||
|
# * #diagonal?
|
||
| ... | ... | |
|
det_of_minor * (-1) ** (row + column)
|
||
|
end
|
||
|
#
|
||
|
# Returns the adjugate of the matrix.
|
||
|
#
|
||
|
# Matrix[ [7,6],[3,9] ].adjugate
|
||
|
# => 9 -6
|
||
|
# -3 7
|
||
|
#
|
||
|
def adjugate
|
||
|
Matrix.Raise ErrDimensionMismatch unless square?
|
||
|
Matrix.build(row_count, column_count) do |row, column|
|
||
|
cofactor(column, row)
|
||
|
end
|
||
|
end
|
||
|
#--
|
||
|
# TESTING -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
|
||
|
#++
|
||
| test/matrix/test_matrix.rb | ||
|---|---|---|
|
assert_raise(ExceptionForMatrix::ErrDimensionMismatch) { Matrix[[2,0,1],[0,-2,2]].cofactor(0, 0) }
|
||
|
end
|
||
|
def test_adjugate
|
||
|
assert_equal(Matrix.empty, Matrix.empty.adjugate)
|
||
|
assert_equal(Matrix[[1]], Matrix[[5]].adjugate)
|
||
|
assert_equal(Matrix[[0,0],[0,0]], Matrix[[0,0],[0,0]].adjugate)
|
||
|
assert_equal(Matrix[[9,-6],[-3,7]], Matrix[[7,6],[3,9]].adjugate)
|
||
|
assert_equal(Matrix[[45,3,-7],[6,-1,0],[-7,0,0]], Matrix[[0,0,1],[0,7,6],[1,3,9]].adjugate)
|
||
|
m = Matrix[[2, 0, 9, 3, 9], [8, 7, 0, 1, 9], [7, 5, 6, 6, 5], [0, 7, 8, 3, 0], [7, 8, 2, 3, 1]]
|
||
|
assert_equal(Matrix.identity(5), (m.adjugate * m) / m.det)
|
||
|
assert_raise(ExceptionForMatrix::ErrDimensionMismatch) { @m1.adjugate }
|
||
|
end
|
||
|
def test_regular?
|
||
|
assert(Matrix[[1, 0], [0, 1]].regular?)
|
||
|
assert(Matrix[[1, 0, 0], [0, 1, 0], [0, 0, 1]].regular?)
|
||