def test_dup_monic(): assert dup_monic([3, 6, 9], ZZ) == [1, 2, 3] raises(ExactQuotientFailed, lambda: dup_monic([3, 4, 5], ZZ)) assert dup_monic([], QQ) == [] assert dup_monic([QQ(1)], QQ) == [QQ(1)] assert dup_monic([QQ(7), QQ(1), QQ(21)], QQ) == [QQ(1), QQ(1, 7), QQ(3)]
def _dup_ff_trivial_gcd(f, g, K): """Handle trivial cases in GCD algorithm over a field. """ if not (f or g): return [], [], [] elif not f: return dup_monic(g, K), [], [dup_LC(g, K)] elif not g: return dup_monic(f, K), [dup_LC(f, K)], [] else: return None
def dup_sqf_part(f, K): """ Returns square-free part of a polynomial in ``K[x]``. Examples ======== >>> from sympy.polys.domains import ZZ >>> from sympy.polys.sqfreetools import dup_sqf_part >>> dup_sqf_part([ZZ(1), ZZ(0), -ZZ(3), -ZZ(2)], ZZ) [1, -1, -2] """ if not K.has_CharacteristicZero: return dup_gf_sqf_part(f, K) if not f: return f if K.is_negative(dup_LC(f, K)): f = dup_neg(f, K) gcd = dup_gcd(f, dup_diff(f, 1, K), K) sqf = dup_quo(f, gcd, K) if K.has_Field or not K.is_Exact: return dup_monic(sqf, K) else: return dup_primitive(sqf, K)[1]
def dup_half_gcdex(f, g, K): """ Half extended Euclidean algorithm in `F[x]`. Returns ``(s, h)`` such that ``h = gcd(f, g)`` and ``s*f = h (mod g)``. Examples ======== >>> from sympy.polys.domains import QQ >>> from sympy.polys.euclidtools import dup_half_gcdex >>> f = QQ.map([1, -2, -6, 12, 15]) >>> g = QQ.map([1, 1, -4, -4]) >>> dup_half_gcdex(f, g, QQ) ([-1/5, 3/5], [1/1, 1/1]) """ if not (K.has_Field or not K.is_Exact): raise DomainError("can't compute half extended GCD over %s" % K) a, b = [K.one], [] while g: q, r = dup_div(f, g, K) f, g = g, r a, b = b, dup_sub_mul(a, q, b, K) a = dup_quo_ground(a, dup_LC(f, K), K) f = dup_monic(f, K) return a, f
def dup_ff_prs_gcd(f, g, K): """ Computes polynomial GCD using subresultants over a field. Returns ``(h, cff, cfg)`` such that ``a = gcd(f, g)``, ``cff = quo(f, h)``, and ``cfg = quo(g, h)``. Examples ======== >>> from sympy.polys.domains import QQ >>> from sympy.polys.euclidtools import dup_ff_prs_gcd >>> f = QQ.map([1, 0, -1]) >>> g = QQ.map([1, -3, 2]) >>> dup_ff_prs_gcd(f, g, QQ) ([1/1, -1/1], [1/1, 1/1], [1/1, -2/1]) """ result = _dup_ff_trivial_gcd(f, g, K) if result is not None: return result h = dup_subresultants(f, g, K)[-1] h = dup_monic(h, K) cff = dup_quo(f, h, K) cfg = dup_quo(g, h, K) return h, cff, cfg
def dup_ext_factor(f, K): """Factor univariate polynomials over algebraic number fields. """ n, lc = dup_degree(f), dup_LC(f, K) f = dup_monic(f, K) if n <= 0: return lc, [] if n == 1: return lc, [(f, 1)] f, F = dup_sqf_part(f, K), f s, g, r = dup_sqf_norm(f, K) factors = dup_factor_list_include(r, K.dom) if len(factors) == 1: return lc, [(f, n // dup_degree(f))] H = s * K.unit for i, (factor, _) in enumerate(factors): h = dup_convert(factor, K.dom, K) h, _, g = dup_inner_gcd(h, g, K) h = dup_shift(h, H, K) factors[i] = h factors = dup_trial_division(F, factors, K) return lc, factors
def dup_sqf_part(f, K): """ Returns square-free part of a polynomial in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_sqf_part(x**3 - 3*x - 2) x**2 - x - 2 """ if K.is_FiniteField: return dup_gf_sqf_part(f, K) if not f: return f if K.is_negative(dup_LC(f, K)): f = dup_neg(f, K) gcd = dup_gcd(f, dup_diff(f, 1, K), K) sqf = dup_quo(f, gcd, K) if K.has_Field: return dup_monic(sqf, K) else: return dup_primitive(sqf, K)[1]
def dup_sqf_part(f, K): """ Returns square-free part of a polynomial in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_sqf_part(x**3 - 3*x - 2) x**2 - x - 2 """ if K.is_FiniteField: return dup_gf_sqf_part(f, K) if not f: return f if K.is_negative(dup_LC(f, K)): f = dup_neg(f, K) gcd = dup_gcd(f, dup_diff(f, 1, K), K) sqf = dup_quo(f, gcd, K) if K.is_Field: return dup_monic(sqf, K) else: return dup_primitive(sqf, K)[1]
def dup_ff_prs_gcd(f, g, K): """ Computes polynomial GCD using subresultants over a field. Returns ``(h, cff, cfg)`` such that ``a = gcd(f, g)``, ``cff = quo(f, h)``, and ``cfg = quo(g, h)``. Examples ======== >>> from sympy.polys import ring, QQ >>> R, x = ring("x", QQ) >>> R.dup_ff_prs_gcd(x**2 - 1, x**2 - 3*x + 2) (x - 1, x + 1, x - 2) """ result = _dup_ff_trivial_gcd(f, g, K) if result is not None: return result h = dup_subresultants(f, g, K)[-1] h = dup_monic(h, K) cff = dup_quo(f, h, K) cfg = dup_quo(g, h, K) return h, cff, cfg
def dup_gff_list(f, K): """ Compute greatest factorial factorization of ``f`` in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_gff_list(x**5 + 2*x**4 - x**3 - 2*x**2) [(x, 1), (x + 2, 4)] """ if not f: raise ValueError("greatest factorial factorization doesn't exist for a zero polynomial") f = dup_monic(f, K) if not dup_degree(f): return [] else: g = dup_gcd(f, dup_shift(f, K.one, K), K) H = dup_gff_list(g, K) for i, (h, k) in enumerate(H): g = dup_mul(g, dup_shift(h, -K(k), K), K) H[i] = (h, k + 1) f = dup_quo(f, g, K) if not dup_degree(f): return H else: return [(f, 1)] + H
def dup_half_gcdex(f, g, K): """ Half extended Euclidean algorithm in `F[x]`. Returns ``(s, h)`` such that ``h = gcd(f, g)`` and ``s*f = h (mod g)``. Examples ======== >>> from sympy.polys import ring, QQ >>> R, x = ring("x", QQ) >>> f = x**4 - 2*x**3 - 6*x**2 + 12*x + 15 >>> g = x**3 + x**2 - 4*x - 4 >>> R.dup_half_gcdex(f, g) (-1/5*x + 3/5, x + 1) """ if not K.has_Field: raise DomainError("can't compute half extended GCD over %s" % K) a, b = [K.one], [] while g: q, r = dup_div(f, g, K) f, g = g, r a, b = b, dup_sub_mul(a, q, b, K) a = dup_quo_ground(a, dup_LC(f, K), K) f = dup_monic(f, K) return a, f
def dup_ff_prs_gcd(f, g, K): """ Computes polynomial GCD using subresultants over a field. Returns ``(h, cff, cfg)`` such that ``a = gcd(f, g)``, ``cff = quo(f, h)``, and ``cfg = quo(g, h)``. **Examples** >>> from sympy.polys.domains import QQ >>> from sympy.polys.euclidtools import dup_ff_prs_gcd >>> f = QQ.map([1, 0, -1]) >>> g = QQ.map([1, -3, 2]) >>> dup_ff_prs_gcd(f, g, QQ) ([1/1, -1/1], [1/1, 1/1], [1/1, -2/1]) """ result = _dup_ff_trivial_gcd(f, g, K) if result is not None: return result h = dup_subresultants(f, g, K)[-1] h = dup_monic(h, K) cff = dup_exquo(f, h, K) cfg = dup_exquo(g, h, K) return h, cff, cfg
def dup_half_gcdex(f, g, K): """ Half extended Euclidean algorithm in ``F[x]``. Returns ``(s, h)`` such that ``h = gcd(f, g)`` and ``s*f = h (mod g)``. **Examples** >>> from sympy.polys.domains import QQ >>> from sympy.polys.euclidtools import dup_half_gcdex >>> f = QQ.map([1, -2, -6, 12, 15]) >>> g = QQ.map([1, 1, -4, -4]) >>> dup_half_gcdex(f, g, QQ) ([-1/5, 3/5], [1/1, 1/1]) """ if not (K.has_Field or not K.is_Exact): raise DomainError("can't compute half extended GCD over %s" % K) a, b = [K.one], [] while g: q, r = dup_div(f, g, K) f, g = g, r a, b = b, dup_sub_mul(a, q, b, K) a = dup_exquo_ground(a, dup_LC(f, K), K) f = dup_monic(f, K) return a, f
def dup_ext_factor(f, K): """Factor univariate polynomials over algebraic number fields. """ n, lc = dup_degree(f), dup_LC(f, K) f = dup_monic(f, K) if n <= 0: return lc, [] if n == 1: return lc, [(f, 1)] f, F = dup_sqf_part(f, K), f s, g, r = dup_sqf_norm(f, K) factors = dup_factor_list_include(r, K.dom) if len(factors) == 1: return lc, [(f, n//dup_degree(f))] H = s*K.unit for i, (factor, _) in enumerate(factors): h = dup_convert(factor, K.dom, K) h, _, g = dup_inner_gcd(h, g, K) h = dup_shift(h, H, K) factors[i] = h factors = dup_trial_division(F, factors, K) return lc, factors
def dup_sqf_list(f, K, all=False): """ Return square-free decomposition of a polynomial in ``K[x]``. Examples ======== >>> from sympy.polys.domains import ZZ >>> from sympy.polys.sqfreetools import dup_sqf_list >>> f = ZZ.map([2, 16, 50, 76, 56, 16]) >>> dup_sqf_list(f, ZZ) (2, [([1, 1], 2), ([1, 2], 3)]) >>> dup_sqf_list(f, ZZ, all=True) (2, [([1], 1), ([1, 1], 2), ([1, 2], 3)]) """ if not K.has_CharacteristicZero: return dup_gf_sqf_list(f, K, all=all) if K.has_Field or not K.is_Exact: coeff = dup_LC(f, K) f = dup_monic(f, K) else: coeff, f = dup_primitive(f, K) if K.is_negative(dup_LC(f, K)): f = dup_neg(f, K) coeff = -coeff if dup_degree(f) <= 0: return coeff, [] result, i = [], 1 h = dup_diff(f, 1, K) g, p, q = dup_inner_gcd(f, h, K) while True: d = dup_diff(p, 1, K) h = dup_sub(q, d, K) if not h: result.append((p, i)) break g, p, q = dup_inner_gcd(p, h, K) if all or dup_degree(g) > 0: result.append((g, i)) i += 1 return coeff, result
def dup_sqf_list(f, K, all=False): """ Return square-free decomposition of a polynomial in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> f = 2*x**5 + 16*x**4 + 50*x**3 + 76*x**2 + 56*x + 16 >>> R.dup_sqf_list(f) (2, [(x + 1, 2), (x + 2, 3)]) >>> R.dup_sqf_list(f, all=True) (2, [(1, 1), (x + 1, 2), (x + 2, 3)]) """ if K.is_FiniteField: return dup_gf_sqf_list(f, K, all=all) if K.has_Field: coeff = dup_LC(f, K) f = dup_monic(f, K) else: coeff, f = dup_primitive(f, K) if K.is_negative(dup_LC(f, K)): f = dup_neg(f, K) coeff = -coeff if dup_degree(f) <= 0: return coeff, [] result, i = [], 1 h = dup_diff(f, 1, K) g, p, q = dup_inner_gcd(f, h, K) while True: d = dup_diff(p, 1, K) h = dup_sub(q, d, K) if not h: result.append((p, i)) break g, p, q = dup_inner_gcd(p, h, K) if all or dup_degree(g) > 0: result.append((g, i)) i += 1 return coeff, result
def dup_sqf_list(f, K, all=False): """ Return square-free decomposition of a polynomial in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> f = 2*x**5 + 16*x**4 + 50*x**3 + 76*x**2 + 56*x + 16 >>> R.dup_sqf_list(f) (2, [(x + 1, 2), (x + 2, 3)]) >>> R.dup_sqf_list(f, all=True) (2, [(1, 1), (x + 1, 2), (x + 2, 3)]) """ if K.is_FiniteField: return dup_gf_sqf_list(f, K, all=all) if K.is_Field: coeff = dup_LC(f, K) f = dup_monic(f, K) else: coeff, f = dup_primitive(f, K) if K.is_negative(dup_LC(f, K)): f = dup_neg(f, K) coeff = -coeff if dup_degree(f) <= 0: return coeff, [] result, i = [], 1 h = dup_diff(f, 1, K) g, p, q = dup_inner_gcd(f, h, K) while True: d = dup_diff(p, 1, K) h = dup_sub(q, d, K) if not h: result.append((p, i)) break g, p, q = dup_inner_gcd(p, h, K) if all or dup_degree(g) > 0: result.append((g, i)) i += 1 return coeff, result
def dup_qq_heu_gcd(f, g, K0): """ Heuristic polynomial GCD in `Q[x]`. Returns ``(h, cff, cfg)`` such that ``a = gcd(f, g)``, ``cff = quo(f, h)``, and ``cfg = quo(g, h)``. Examples ======== >>> from sympy.polys import ring, QQ >>> R, x = ring("x", QQ) >>> f = QQ(1,2)*x**2 + QQ(7,4)*x + QQ(3,2) >>> g = QQ(1,2)*x**2 + x >>> R.dup_qq_heu_gcd(f, g) (x + 2, 1/2*x + 3/4, 1/2*x) """ result = _dup_ff_trivial_gcd(f, g, K0) if result is not None: return result K1 = K0.get_ring() cf, f = dup_clear_denoms(f, K0, K1) cg, g = dup_clear_denoms(g, K0, K1) f = dup_convert(f, K0, K1) g = dup_convert(g, K0, K1) h, cff, cfg = dup_zz_heu_gcd(f, g, K1) h = dup_convert(h, K1, K0) c = dup_LC(h, K0) h = dup_monic(h, K0) cff = dup_convert(cff, K1, K0) cfg = dup_convert(cfg, K1, K0) cff = dup_mul_ground(cff, K0.quo(c, cf), K0) cfg = dup_mul_ground(cfg, K0.quo(c, cg), K0) return h, cff, cfg
def dup_qq_heu_gcd(f, g, K0): """ Heuristic polynomial GCD in `Q[x]`. Returns ``(h, cff, cfg)`` such that ``a = gcd(f, g)``, ``cff = quo(f, h)``, and ``cfg = quo(g, h)``. Examples ======== >>> from sympy.polys.domains import QQ >>> from sympy.polys.euclidtools import dup_qq_heu_gcd >>> f = [QQ(1,2), QQ(7,4), QQ(3,2)] >>> g = [QQ(1,2), QQ(1), QQ(0)] >>> dup_qq_heu_gcd(f, g, QQ) ([1/1, 2/1], [1/2, 3/4], [1/2, 0/1]) """ result = _dup_ff_trivial_gcd(f, g, K0) if result is not None: return result K1 = K0.get_ring() cf, f = dup_clear_denoms(f, K0, K1) cg, g = dup_clear_denoms(g, K0, K1) f = dup_convert(f, K0, K1) g = dup_convert(g, K0, K1) h, cff, cfg = dup_zz_heu_gcd(f, g, K1) h = dup_convert(h, K1, K0) c = dup_LC(h, K0) h = dup_monic(h, K0) cff = dup_convert(cff, K1, K0) cfg = dup_convert(cfg, K1, K0) cff = dup_mul_ground(cff, K0.quo(c, cf), K0) cfg = dup_mul_ground(cfg, K0.quo(c, cg), K0) return h, cff, cfg
def dup_ff_lcm(f, g, K): """ Computes polynomial LCM over a field in ``K[x]``. **Examples** >>> from sympy.polys.domains import QQ >>> from sympy.polys.euclidtools import dup_ff_lcm >>> f = [QQ(1,2), QQ(7,4), QQ(3,2)] >>> g = [QQ(1,2), QQ(1), QQ(0)] >>> dup_ff_lcm(f, g, QQ) [1/1, 7/2, 3/1, 0/1] """ h = dup_quo(dup_mul(f, g, K), dup_gcd(f, g, K), K) return dup_monic(h, K)
def dup_ff_lcm(f, g, K): """ Computes polynomial LCM over a field in ``K[x]``. **Examples** >>> from sympy.polys.domains import QQ >>> from sympy.polys.euclidtools import dup_ff_lcm >>> f = [QQ(1,2), QQ(7,4), QQ(3,2)] >>> g = [QQ(1,2), QQ(1), QQ(0)] >>> dup_ff_lcm(f, g, QQ) [1/1, 7/2, 3/1, 0/1] """ h = dup_exquo(dup_mul(f, g, K), dup_gcd(f, g, K), K) return dup_monic(h, K)
def dup_ff_lcm(f, g, K): """ Computes polynomial LCM over a field in `K[x]`. Examples ======== >>> from sympy.polys import ring, QQ >>> R, x = ring("x", QQ) >>> f = QQ(1,2)*x**2 + QQ(7,4)*x + QQ(3,2) >>> g = QQ(1,2)*x**2 + x >>> R.dup_ff_lcm(f, g) x**3 + 7/2*x**2 + 3*x """ h = dup_quo(dup_mul(f, g, K), dup_gcd(f, g, K), K) return dup_monic(h, K)
def dup_gff_list(f, K): """ Compute greatest factorial factorization of ``f`` in ``K[x]``. Examples ======== >>> from sympy.polys.domains import ZZ >>> from sympy.polys.sqfreetools import dup_gff_list >>> f = ZZ.map([1, 2, -1, -2, 0, 0]) >>> dup_gff_list(f, ZZ) [([1, 0], 1), ([1, 2], 4)] """ if not f: raise ValueError( "greatest factorial factorization doesn't exist for a zero polynomial" ) f = dup_monic(f, K) if not dup_degree(f): return [] else: g = dup_gcd(f, dup_shift(f, K.one, K), K) H = dup_gff_list(g, K) for i, (h, k) in enumerate(H): g = dup_mul(g, dup_shift(h, -K(k), K), K) H[i] = (h, k + 1) f = dup_quo(f, g, K) if not dup_degree(f): return H else: return [(f, 1)] + H
def dup_gff_list(f, K): """ Compute greatest factorial factorization of ``f`` in ``K[x]``. Examples ======== >>> from sympy.polys.domains import ZZ >>> from sympy.polys.sqfreetools import dup_gff_list >>> f = ZZ.map([1, 2, -1, -2, 0, 0]) >>> dup_gff_list(f, ZZ) [([1, 0], 1), ([1, 2], 4)] """ if not f: raise ValueError("greatest factorial factorization doesn't exist for a zero polynomial") f = dup_monic(f, K) if not dup_degree(f): return [] else: g = dup_gcd(f, dup_shift(f, K.one, K), K) H = dup_gff_list(g, K) for i, (h, k) in enumerate(H): g = dup_mul(g, dup_shift(h, -K(k), K), K) H[i] = (h, k + 1) f = dup_quo(f, g, K) if not dup_degree(f): return H else: return [(f, 1)] + H