我有一个多项式的 4x4 符号矩阵:
S = Matrix([[Poly(alpha**4 + alpha**3, alpha, modulus=2), Poly(alpha**4 + alpha**3 + alpha + 1, alpha, modulus=2),Poly(alpha**3 + alpha**2 + alpha, alpha, modulus=2), Poly(alpha**4 + alpha**3 + alpha**2 + alpha, alpha, modulus=2)],
[Poly(alpha**4 + alpha**3 + alpha + 1, alpha, modulus=2), Poly(alpha**3 + alpha**2 + alpha, alpha, modulus=2), Poly(alpha**4 + alpha**3 + alpha**2 + alpha, alpha, modulus=2),Poly(alpha**3 + alpha**2, alpha, modulus=2)],
[Poly(alpha**3 + alpha**2 + alpha, alpha, modulus=2), Poly(alpha**4 + alpha**3 + alpha**2 + alpha, alpha, modulus=2), Poly(alpha**3 + alpha**2, alpha, modulus=2), Poly(alpha**4 + alpha + 1, alpha, modulus=2)],
[Poly(alpha**4 + alpha**3 + alpha**2 + alpha, alpha, modulus=2), Poly(alpha**3 + alpha**2, alpha, modulus=2), Poly(alpha**4 + alpha + 1, alpha, modulus=2),Poly(alpha**2 + alpha + 1, alpha, modulus=2)]])
目标是获取 S.det(( 并设置域:
S_det = (S.det()).set_domain(GF(self.q))
调试器输出:
File "/home/gamergod77/work/Staircase codes/Product Codes/bchcoder.py", line 52, in decode
S_det = (S.det()).set_domain(GF(self.q))
File "/home/gamergod77/.local/lib/python3.8/site-packages/sympy/matrices/matrices.py", line 123, in det
return _det(self, method=method, iszerofunc=iszerofunc)
File "/home/gamergod77/.local/lib/python3.8/site-packages/sympy/matrices/determinant.py", line 596, in _det
return M._eval_det_bareiss(iszerofunc=iszerofunc)
File "/home/gamergod77/.local/lib/python3.8/site-packages/sympy/matrices/matrices.py", line 99, in _eval_det_bareiss
return _det_bareiss(self, iszerofunc=iszerofunc)
File "/home/gamergod77/.local/lib/python3.8/site-packages/sympy/matrices/determinant.py", line 669, in _det_bareiss
return bareiss(M)
File "/home/gamergod77/.local/lib/python3.8/site-packages/sympy/matrices/determinant.py", line 637, in bareiss
pivot_pos, pivot_val, _, _ = _find_reasonable_pivot(mat[:, 0], iszerofunc=iszerofunc)
File "/home/gamergod77/.local/lib/python3.8/site-packages/sympy/matrices/determinant.py", line 56, in _find_reasonable_pivot
is_zero = iszerofunc(x)
File "/home/gamergod77/.local/lib/python3.8/site-packages/sympy/matrices/utilities.py", line 84, in _is_zero_after_expand_mul
return expand_mul(x) == 0
File "/home/gamergod77/.local/lib/python3.8/site-packages/sympy/core/function.py", line 2799, in expand_mul
return sympify(expr).expand(deep=deep, mul=True, power_exp=False,
AttributeError: 'Poly' object has no attribute 'expand'
请注意,类似的东西
S[:3, :3].det().set_domain(GF(2))
使用相同的 S 通过完美
您应该在矩阵中使用Expr
,或者应该改用PolyMatrix
。看起来使用Expr
最适合您的示例:
In [5]: S = S.applyfunc(lambda p: p.as_expr())
In [6]: S
Out[6]:
⎡ 4 3 4 3 3 2 4 3 2 ⎤
⎢ α + α α + α + α + 1 α + α + α α + α + α + α⎥
⎢ ⎥
⎢ 4 3 3 2 4 3 2 3 2 ⎥
⎢α + α + α + 1 α + α + α α + α + α + α α + α ⎥
⎢ ⎥
⎢ 3 2 4 3 2 3 2 4 ⎥
⎢ α + α + α α + α + α + α α + α α + α + 1 ⎥
⎢ ⎥
⎢ 4 3 2 3 2 4 2 ⎥
⎣α + α + α + α α + α α + α + 1 α + α + 1 ⎦
In [7]: S.det()
Out[7]:
15 14 13 12 11 10 9 8 7 5 4 3 2
α + 3⋅α + 4⋅α + 4⋅α - 2⋅α - 3⋅α + 6⋅α + 9⋅α + α + 5⋅α + 2⋅α + α + 5⋅α + 4⋅α + 1
In [8]: d = S.det()
In [9]: d
Out[9]:
15 14 13 12 11 10 9 8 7 5 4 3 2
α + 3⋅α + 4⋅α + 4⋅α - 2⋅α - 3⋅α + 6⋅α + 9⋅α + α + 5⋅α + 2⋅α + α + 5⋅α + 4⋅α + 1
In [10]: Poly(d, alpha).set_domain(GF(2))
Out[10]: Poly(alpha**15 + alpha**14 + alpha**10 + alpha**8 + alpha**7 + alpha**5 + alpha**3 + alpha**2 + 1, alpha, modulus=2)