Traktor/myenv/Lib/site-packages/sympy/matrices/tests/test_determinant.py
2024-05-23 01:57:24 +02:00

415 lines
13 KiB
Python

import random
from sympy.core.numbers import I
from sympy.core.numbers import Rational
from sympy.core.symbol import (Symbol, symbols)
from sympy.functions.elementary.miscellaneous import sqrt
from sympy.polys.polytools import Poly
from sympy.matrices import Matrix, eye, ones
from sympy.abc import x, y, z
from sympy.testing.pytest import raises
from sympy.matrices.common import NonSquareMatrixError
from sympy.functions.combinatorial.factorials import factorial, subfactorial
def test_determinant():
M = Matrix()
assert M.det() == 1
# Evaluating these directly because they are never reached via M.det()
assert M._eval_det_bareiss() == 1
assert M._eval_det_berkowitz() == 1
assert M._eval_det_lu() == 1
M = Matrix([ [0] ])
assert M.det() == 0
assert M._eval_det_bareiss() == 0
assert M._eval_det_berkowitz() == 0
assert M._eval_det_lu() == 0
M = Matrix([ [5] ])
assert M.det() == 5
assert M._eval_det_bareiss() == 5
assert M._eval_det_berkowitz() == 5
assert M._eval_det_lu() == 5
M = Matrix(( (-3, 2),
( 8, -5) ))
assert M.det(method="domain-ge") == -1
assert M.det(method="bareiss") == -1
assert M.det(method="berkowitz") == -1
assert M.det(method="lu") == -1
M = Matrix(( (x, 1),
(y, 2*y) ))
assert M.det(method="domain-ge") == 2*x*y - y
assert M.det(method="bareiss") == 2*x*y - y
assert M.det(method="berkowitz") == 2*x*y - y
assert M.det(method="lu") == 2*x*y - y
M = Matrix(( (1, 1, 1),
(1, 2, 3),
(1, 3, 6) ))
assert M.det(method="domain-ge") == 1
assert M.det(method="bareiss") == 1
assert M.det(method="berkowitz") == 1
assert M.det(method="lu") == 1
M = Matrix(( ( 3, -2, 0, 5),
(-2, 1, -2, 2),
( 0, -2, 5, 0),
( 5, 0, 3, 4) ))
assert M.det(method="domain-ge") == -289
assert M.det(method="bareiss") == -289
assert M.det(method="berkowitz") == -289
assert M.det(method="lu") == -289
M = Matrix(( ( 1, 2, 3, 4),
( 5, 6, 7, 8),
( 9, 10, 11, 12),
(13, 14, 15, 16) ))
assert M.det(method="domain-ge") == 0
assert M.det(method="bareiss") == 0
assert M.det(method="berkowitz") == 0
assert M.det(method="lu") == 0
M = Matrix(( (3, 2, 0, 0, 0),
(0, 3, 2, 0, 0),
(0, 0, 3, 2, 0),
(0, 0, 0, 3, 2),
(2, 0, 0, 0, 3) ))
assert M.det(method="domain-ge") == 275
assert M.det(method="bareiss") == 275
assert M.det(method="berkowitz") == 275
assert M.det(method="lu") == 275
M = Matrix(( ( 3, 0, 0, 0),
(-2, 1, 0, 0),
( 0, -2, 5, 0),
( 5, 0, 3, 4) ))
assert M.det(method="domain-ge") == 60
assert M.det(method="bareiss") == 60
assert M.det(method="berkowitz") == 60
assert M.det(method="lu") == 60
M = Matrix(( ( 1, 0, 0, 0),
( 5, 0, 0, 0),
( 9, 10, 11, 0),
(13, 14, 15, 16) ))
assert M.det(method="domain-ge") == 0
assert M.det(method="bareiss") == 0
assert M.det(method="berkowitz") == 0
assert M.det(method="lu") == 0
M = Matrix(( (3, 2, 0, 0, 0),
(0, 3, 2, 0, 0),
(0, 0, 3, 2, 0),
(0, 0, 0, 3, 2),
(0, 0, 0, 0, 3) ))
assert M.det(method="domain-ge") == 243
assert M.det(method="bareiss") == 243
assert M.det(method="berkowitz") == 243
assert M.det(method="lu") == 243
M = Matrix(( (1, 0, 1, 2, 12),
(2, 0, 1, 1, 4),
(2, 1, 1, -1, 3),
(3, 2, -1, 1, 8),
(1, 1, 1, 0, 6) ))
assert M.det(method="domain-ge") == -55
assert M.det(method="bareiss") == -55
assert M.det(method="berkowitz") == -55
assert M.det(method="lu") == -55
M = Matrix(( (-5, 2, 3, 4, 5),
( 1, -4, 3, 4, 5),
( 1, 2, -3, 4, 5),
( 1, 2, 3, -2, 5),
( 1, 2, 3, 4, -1) ))
assert M.det(method="domain-ge") == 11664
assert M.det(method="bareiss") == 11664
assert M.det(method="berkowitz") == 11664
assert M.det(method="lu") == 11664
M = Matrix(( ( 2, 7, -1, 3, 2),
( 0, 0, 1, 0, 1),
(-2, 0, 7, 0, 2),
(-3, -2, 4, 5, 3),
( 1, 0, 0, 0, 1) ))
assert M.det(method="domain-ge") == 123
assert M.det(method="bareiss") == 123
assert M.det(method="berkowitz") == 123
assert M.det(method="lu") == 123
M = Matrix(( (x, y, z),
(1, 0, 0),
(y, z, x) ))
assert M.det(method="domain-ge") == z**2 - x*y
assert M.det(method="bareiss") == z**2 - x*y
assert M.det(method="berkowitz") == z**2 - x*y
assert M.det(method="lu") == z**2 - x*y
# issue 13835
a = symbols('a')
M = lambda n: Matrix([[i + a*j for i in range(n)]
for j in range(n)])
assert M(5).det() == 0
assert M(6).det() == 0
assert M(7).det() == 0
def test_issue_14517():
M = Matrix([
[ 0, 10*I, 10*I, 0],
[10*I, 0, 0, 10*I],
[10*I, 0, 5 + 2*I, 10*I],
[ 0, 10*I, 10*I, 5 + 2*I]])
ev = M.eigenvals()
# test one random eigenvalue, the computation is a little slow
test_ev = random.choice(list(ev.keys()))
assert (M - test_ev*eye(4)).det() == 0
def test_legacy_det():
# Minimal support for legacy keys for 'method' in det()
# Partially copied from test_determinant()
M = Matrix(( ( 3, -2, 0, 5),
(-2, 1, -2, 2),
( 0, -2, 5, 0),
( 5, 0, 3, 4) ))
assert M.det(method="bareis") == -289
assert M.det(method="det_lu") == -289
assert M.det(method="det_LU") == -289
M = Matrix(( (3, 2, 0, 0, 0),
(0, 3, 2, 0, 0),
(0, 0, 3, 2, 0),
(0, 0, 0, 3, 2),
(2, 0, 0, 0, 3) ))
assert M.det(method="bareis") == 275
assert M.det(method="det_lu") == 275
assert M.det(method="Bareis") == 275
M = Matrix(( (1, 0, 1, 2, 12),
(2, 0, 1, 1, 4),
(2, 1, 1, -1, 3),
(3, 2, -1, 1, 8),
(1, 1, 1, 0, 6) ))
assert M.det(method="bareis") == -55
assert M.det(method="det_lu") == -55
assert M.det(method="BAREISS") == -55
M = Matrix(( ( 3, 0, 0, 0),
(-2, 1, 0, 0),
( 0, -2, 5, 0),
( 5, 0, 3, 4) ))
assert M.det(method="bareiss") == 60
assert M.det(method="berkowitz") == 60
assert M.det(method="lu") == 60
M = Matrix(( ( 1, 0, 0, 0),
( 5, 0, 0, 0),
( 9, 10, 11, 0),
(13, 14, 15, 16) ))
assert M.det(method="bareiss") == 0
assert M.det(method="berkowitz") == 0
assert M.det(method="lu") == 0
M = Matrix(( (3, 2, 0, 0, 0),
(0, 3, 2, 0, 0),
(0, 0, 3, 2, 0),
(0, 0, 0, 3, 2),
(0, 0, 0, 0, 3) ))
assert M.det(method="bareiss") == 243
assert M.det(method="berkowitz") == 243
assert M.det(method="lu") == 243
M = Matrix(( (-5, 2, 3, 4, 5),
( 1, -4, 3, 4, 5),
( 1, 2, -3, 4, 5),
( 1, 2, 3, -2, 5),
( 1, 2, 3, 4, -1) ))
assert M.det(method="bareis") == 11664
assert M.det(method="det_lu") == 11664
assert M.det(method="BERKOWITZ") == 11664
M = Matrix(( ( 2, 7, -1, 3, 2),
( 0, 0, 1, 0, 1),
(-2, 0, 7, 0, 2),
(-3, -2, 4, 5, 3),
( 1, 0, 0, 0, 1) ))
assert M.det(method="bareis") == 123
assert M.det(method="det_lu") == 123
assert M.det(method="LU") == 123
def eye_Determinant(n):
return Matrix(n, n, lambda i, j: int(i == j))
def zeros_Determinant(n):
return Matrix(n, n, lambda i, j: 0)
def test_det():
a = Matrix(2, 3, [1, 2, 3, 4, 5, 6])
raises(NonSquareMatrixError, lambda: a.det())
z = zeros_Determinant(2)
ey = eye_Determinant(2)
assert z.det() == 0
assert ey.det() == 1
x = Symbol('x')
a = Matrix(0, 0, [])
b = Matrix(1, 1, [5])
c = Matrix(2, 2, [1, 2, 3, 4])
d = Matrix(3, 3, [1, 2, 3, 4, 5, 6, 7, 8, 8])
e = Matrix(4, 4,
[x, 1, 2, 3, 4, 5, 6, 7, 2, 9, 10, 11, 12, 13, 14, 14])
from sympy.abc import i, j, k, l, m, n
f = Matrix(3, 3, [i, l, m, 0, j, n, 0, 0, k])
g = Matrix(3, 3, [i, 0, 0, l, j, 0, m, n, k])
h = Matrix(3, 3, [x**3, 0, 0, i, x**-1, 0, j, k, x**-2])
# the method keyword for `det` doesn't kick in until 4x4 matrices,
# so there is no need to test all methods on smaller ones
assert a.det() == 1
assert b.det() == 5
assert c.det() == -2
assert d.det() == 3
assert e.det() == 4*x - 24
assert e.det(method="domain-ge") == 4*x - 24
assert e.det(method='bareiss') == 4*x - 24
assert e.det(method='berkowitz') == 4*x - 24
assert f.det() == i*j*k
assert g.det() == i*j*k
assert h.det() == 1
raises(ValueError, lambda: e.det(iszerofunc="test"))
def test_permanent():
M = Matrix([[1, 2, 3], [4, 5, 6], [7, 8, 9]])
assert M.per() == 450
for i in range(1, 12):
assert ones(i, i).per() == ones(i, i).T.per() == factorial(i)
assert (ones(i, i)-eye(i)).per() == (ones(i, i)-eye(i)).T.per() == subfactorial(i)
a1, a2, a3, a4, a5 = symbols('a_1 a_2 a_3 a_4 a_5')
M = Matrix([a1, a2, a3, a4, a5])
assert M.per() == M.T.per() == a1 + a2 + a3 + a4 + a5
def test_adjugate():
x = Symbol('x')
e = Matrix(4, 4,
[x, 1, 2, 3, 4, 5, 6, 7, 2, 9, 10, 11, 12, 13, 14, 14])
adj = Matrix([
[ 4, -8, 4, 0],
[ 76, -14*x - 68, 14*x - 8, -4*x + 24],
[-122, 17*x + 142, -21*x + 4, 8*x - 48],
[ 48, -4*x - 72, 8*x, -4*x + 24]])
assert e.adjugate() == adj
assert e.adjugate(method='bareiss') == adj
assert e.adjugate(method='berkowitz') == adj
a = Matrix(2, 3, [1, 2, 3, 4, 5, 6])
raises(NonSquareMatrixError, lambda: a.adjugate())
def test_util():
R = Rational
v1 = Matrix(1, 3, [1, 2, 3])
v2 = Matrix(1, 3, [3, 4, 5])
assert v1.norm() == sqrt(14)
assert v1.project(v2) == Matrix(1, 3, [R(39)/25, R(52)/25, R(13)/5])
assert Matrix.zeros(1, 2) == Matrix(1, 2, [0, 0])
assert ones(1, 2) == Matrix(1, 2, [1, 1])
assert v1.copy() == v1
# cofactor
assert eye(3) == eye(3).cofactor_matrix()
test = Matrix([[1, 3, 2], [2, 6, 3], [2, 3, 6]])
assert test.cofactor_matrix() == \
Matrix([[27, -6, -6], [-12, 2, 3], [-3, 1, 0]])
test = Matrix([[1, 2, 3], [4, 5, 6], [7, 8, 9]])
assert test.cofactor_matrix() == \
Matrix([[-3, 6, -3], [6, -12, 6], [-3, 6, -3]])
def test_cofactor_and_minors():
x = Symbol('x')
e = Matrix(4, 4,
[x, 1, 2, 3, 4, 5, 6, 7, 2, 9, 10, 11, 12, 13, 14, 14])
m = Matrix([
[ x, 1, 3],
[ 2, 9, 11],
[12, 13, 14]])
cm = Matrix([
[ 4, 76, -122, 48],
[-8, -14*x - 68, 17*x + 142, -4*x - 72],
[ 4, 14*x - 8, -21*x + 4, 8*x],
[ 0, -4*x + 24, 8*x - 48, -4*x + 24]])
sub = Matrix([
[x, 1, 2],
[4, 5, 6],
[2, 9, 10]])
assert e.minor_submatrix(1, 2) == m
assert e.minor_submatrix(-1, -1) == sub
assert e.minor(1, 2) == -17*x - 142
assert e.cofactor(1, 2) == 17*x + 142
assert e.cofactor_matrix() == cm
assert e.cofactor_matrix(method="bareiss") == cm
assert e.cofactor_matrix(method="berkowitz") == cm
raises(ValueError, lambda: e.cofactor(4, 5))
raises(ValueError, lambda: e.minor(4, 5))
raises(ValueError, lambda: e.minor_submatrix(4, 5))
a = Matrix(2, 3, [1, 2, 3, 4, 5, 6])
assert a.minor_submatrix(0, 0) == Matrix([[5, 6]])
raises(ValueError, lambda:
Matrix(0, 0, []).minor_submatrix(0, 0))
raises(NonSquareMatrixError, lambda: a.cofactor(0, 0))
raises(NonSquareMatrixError, lambda: a.minor(0, 0))
raises(NonSquareMatrixError, lambda: a.cofactor_matrix())
def test_charpoly():
x, y = Symbol('x'), Symbol('y')
z, t = Symbol('z'), Symbol('t')
from sympy.abc import a,b,c
m = Matrix(3, 3, [1, 2, 3, 4, 5, 6, 7, 8, 9])
assert eye_Determinant(3).charpoly(x) == Poly((x - 1)**3, x)
assert eye_Determinant(3).charpoly(y) == Poly((y - 1)**3, y)
assert m.charpoly() == Poly(x**3 - 15*x**2 - 18*x, x)
raises(NonSquareMatrixError, lambda: Matrix([[1], [2]]).charpoly())
n = Matrix(4, 4, [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0])
assert n.charpoly() == Poly(x**4, x)
n = Matrix(4, 4, [45, 0, 0, 0, 0, 23, 0, 0, 0, 0, 87, 0, 0, 0, 0, 12])
assert n.charpoly() == Poly(x**4 - 167*x**3 + 8811*x**2 - 173457*x + 1080540, x)
n = Matrix(3, 3, [x, 0, 0, a, y, 0, b, c, z])
assert n.charpoly() == Poly(t**3 - (x+y+z)*t**2 + t*(x*y+y*z+x*z) - x*y*z, t)