def dmp_fateman_poly_F_1(n, K):
"""Fateman's GCD benchmark: trivial GCD """
u = [K(1), K(0)]
for i in range(0, n):
u = [dmp_one(i, K), u]
v = [K(1), K(0), K(0)]
for i in range(0, n):
v = [dmp_one(i, K), dmp_zero(i), v]
m = n - 1
U = dmp_add_term(u, dmp_ground(K(1), m), 0, n, K)
V = dmp_add_term(u, dmp_ground(K(2), m), 0, n, K)
f = [[-K(3), K(0)], [], [K(1), K(0), -K(1)]]
W = dmp_add_term(v, dmp_ground(K(1), m), 0, n, K)
Y = dmp_raise(f, m, 1, K)
F = dmp_mul(U, V, n, K)
G = dmp_mul(W, Y, n, K)
H = dmp_one(n, K)
return F, G, H
def _dmp_ff_trivial_gcd(f, g, u, K):
"""Handle trivial cases in GCD algorithm over a field. """
zero_f = dmp_zero_p(f, u)
zero_g = dmp_zero_p(g, u)
if zero_f and zero_g:
return tuple(dmp_zeros(3, u, K))
elif zero_f:
return (dmp_ground_monic(g, u, K), dmp_zero(u),
dmp_ground(dmp_ground_LC(g, u, K), u))
elif zero_g:
return (dmp_ground_monic(f, u, K), dmp_ground(dmp_ground_LC(f, u, K),
u), dmp_zero(u))
elif query('USE_SIMPLIFY_GCD'):
return _dmp_simplify_gcd(f, g, u, K)
def dmp_sqf_list_include(f, u, K, all=False):
"""
Return square-free decomposition of a polynomial in ``K[x]``.
Examples
========
>>> from diofant.polys import ring, ZZ
>>> R, x,y = ring("x,y", ZZ)
>>> f = x**5 + 2*x**4*y + x**3*y**2
>>> R.dmp_sqf_list_include(f)
[(1, 1), (x + y, 2), (x, 3)]
>>> R.dmp_sqf_list_include(f, all=True)
[(1, 1), (x + y, 2), (x, 3)]
"""
if not u:
return dup_sqf_list_include(f, K, all=all)
coeff, factors = dmp_sqf_list(f, u, K, all=all)
if factors and factors[0][1] == 1:
g = dmp_mul_ground(factors[0][0], coeff, u, K)
return [(g, 1)] + factors[1:]
else:
g = dmp_ground(coeff, u)
return [(g, 1)] + factors
def dup_real_imag(f, K):
"""
Return bivariate polynomials ``f1`` and ``f2``, such that ``f = f1 + f2*I``.
Examples
========
>>> from diofant.polys import ring, ZZ
>>> R, x,y = ring("x,y", ZZ)
>>> R.dup_real_imag(x**3 + x**2 + x + 1)
(x**3 + x**2 - 3*x*y**2 + x - y**2 + 1, 3*x**2*y + 2*x*y - y**3 + y)
"""
if not K.is_ZZ and not K.is_QQ:
raise DomainError(
"computing real and imaginary parts is not supported over %s" % K)
f1 = dmp_zero(1)
f2 = dmp_zero(1)
if not f:
return f1, f2
g = [[[K.one, K.zero]], [[K.one], []]]
h = dmp_ground(f[0], 2)
for c in f[1:]:
h = dmp_mul(h, g, 2, K)
h = dmp_add_term(h, dmp_ground(c, 1), 0, 2, K)
H = dup_to_raw_dict(h)
for k, h in H.items():
m = k % 4
if not m:
f1 = dmp_add(f1, h, 1, K)
elif m == 1:
f2 = dmp_add(f2, h, 1, K)
elif m == 2:
f1 = dmp_sub(f1, h, 1, K)
else:
f2 = dmp_sub(f2, h, 1, K)
return f1, f2
def _dmp_rr_trivial_gcd(f, g, u, K):
"""Handle trivial cases in GCD algorithm over a ring. """
zero_f = dmp_zero_p(f, u)
zero_g = dmp_zero_p(g, u)
if zero_f and zero_g:
return tuple(dmp_zeros(3, u, K))
elif zero_f:
if K.is_nonnegative(dmp_ground_LC(g, u, K)):
return g, dmp_zero(u), dmp_one(u, K)
else:
return dmp_neg(g, u, K), dmp_zero(u), dmp_ground(-K.one, u)
elif zero_g:
if K.is_nonnegative(dmp_ground_LC(f, u, K)):
return f, dmp_one(u, K), dmp_zero(u)
else:
return dmp_neg(f, u, K), dmp_ground(-K.one, u), dmp_zero(u)
elif dmp_one_p(f, u, K) or dmp_one_p(g, u, K):
return dmp_one(u, K), f, g
elif query('USE_SIMPLIFY_GCD'):
return _dmp_simplify_gcd(f, g, u, K)
def dmp_factor_list_include(f, u, K):
"""Factor polynomials into irreducibles in `K[X]`. """
if not u:
return dup_factor_list_include(f, K)
coeff, factors = dmp_factor_list(f, u, K)
if not factors:
return [(dmp_ground(coeff, u), 1)]
else:
g = dmp_mul_ground(factors[0][0], coeff, u, K)
return [(g, factors[0][1])] + factors[1:]
def dmp_add_ground(f, c, u, K):
"""
Add an element of the ground domain to ``f``.
Examples
========
>>> from diofant.polys import ring, ZZ
>>> R, x,y = ring("x,y", ZZ)
>>> R.dmp_add_ground(x**3 + 2*x**2 + 3*x + 4, ZZ(4))
x**3 + 2*x**2 + 3*x + 8
"""
return dmp_add_term(f, dmp_ground(c, u - 1), 0, u, K)
def dmp_fateman_poly_F_3(n, K):
"""Fateman's GCD benchmark: sparse inputs (deg f ~ vars f) """
u = dup_from_raw_dict({n + 1: K.one}, K)
for i in range(0, n - 1):
u = dmp_add_term([u], dmp_one(i, K), n + 1, i + 1, K)
v = dmp_add_term(u, dmp_ground(K(2), n - 2), 0, n, K)
f = dmp_sqr(
dmp_add_term([dmp_neg(v, n - 1, K)], dmp_one(n - 1, K), n + 1, n, K),
n, K)
g = dmp_sqr(dmp_add_term([v], dmp_one(n - 1, K), n + 1, n, K), n, K)
v = dmp_add_term(u, dmp_one(n - 2, K), 0, n - 1, K)
h = dmp_sqr(dmp_add_term([v], dmp_one(n - 1, K), n + 1, n, K), n, K)
return dmp_mul(f, h, n, K), dmp_mul(g, h, n, K), h
def dmp_fateman_poly_F_2(n, K):
"""Fateman's GCD benchmark: linearly dense quartic inputs """
u = [K(1), K(0)]
for i in range(0, n - 1):
u = [dmp_one(i, K), u]
m = n - 1
v = dmp_add_term(u, dmp_ground(K(2), m - 1), 0, n, K)
f = dmp_sqr([dmp_one(m, K), dmp_neg(v, m, K)], n, K)
g = dmp_sqr([dmp_one(m, K), v], n, K)
v = dmp_add_term(u, dmp_one(m - 1, K), 0, n, K)
h = dmp_sqr([dmp_one(m, K), v], n, K)
return dmp_mul(f, h, n, K), dmp_mul(g, h, n, K), h
def test_dmp_ground():
assert dmp_ground(ZZ(0), 2) == [[[]]]
assert dmp_ground(ZZ(7), -1) == ZZ(7)
assert dmp_ground(ZZ(7), 0) == [ZZ(7)]
assert dmp_ground(ZZ(7), 2) == [[[ZZ(7)]]]
def dmp_inner_subresultants(f, g, u, K):
"""
Subresultant PRS algorithm in `K[X]`.
Examples
========
>>> from diofant.polys import ring, ZZ
>>> R, x,y = ring("x,y", ZZ)
>>> f = 3*x**2*y - y**3 - 4
>>> g = x**2 + x*y**3 - 9
>>> a = 3*x*y**4 + y**3 - 27*y + 4
>>> b = -3*y**10 - 12*y**7 + y**6 - 54*y**4 + 8*y**3 + 729*y**2 - 216*y + 16
>>> prs = [f, g, a, b]
>>> sres = [[1], [1], [3, 0, 0, 0, 0], [-3, 0, 0, -12, 1, 0, -54, 8, 729, -216, 16]]
>>> R.dmp_inner_subresultants(f, g) == (prs, sres)
True
"""
if not u:
return dup_inner_subresultants(f, g, K)
n = dmp_degree(f, u)
m = dmp_degree(g, u)
if n < m:
f, g = g, f
n, m = m, n
if dmp_zero_p(f, u):
return [], []
v = u - 1
if dmp_zero_p(g, u):
return [f], [dmp_ground(K.one, v)]
R = [f, g]
d = n - m
b = dmp_pow(dmp_ground(-K.one, v), d + 1, v, K)
h = dmp_prem(f, g, u, K)
h = dmp_mul_term(h, b, 0, u, K)
lc = dmp_LC(g, K)
c = dmp_pow(lc, d, v, K)
S = [dmp_ground(K.one, v), c]
c = dmp_neg(c, v, K)
while not dmp_zero_p(h, u):
k = dmp_degree(h, u)
R.append(h)
f, g, m, d = g, h, k, m - k
b = dmp_mul(dmp_neg(lc, v, K), dmp_pow(c, d, v, K), v, K)
h = dmp_prem(f, g, u, K)
h = [dmp_quo(ch, b, v, K) for ch in h]
lc = dmp_LC(g, K)
if d > 1:
p = dmp_pow(dmp_neg(lc, v, K), d, v, K)
q = dmp_pow(c, d - 1, v, K)
c = dmp_quo(p, q, v, K)
else:
c = dmp_neg(lc, v, K)
S.append(dmp_neg(c, v, K))
return R, S