def testSubtraction(self):
Z = self.Z
f = uniutil.polynomial(enumerate(range(1, 6)), Z)
# sf bug # 1937925
f2 = uniutil.polynomial([(1, 2), (2, 3), (3, 4), (4, 5)], Z)
self.assertEqual(f2, f - 1)
self.assertEqual(-f2, 1 - f)
def _small_irriducible(char, degree):
"""
Return an irreducible polynomial of self.degree with a small
number of non-zero coefficients.
"""
cardinality = char**degree
basefield = FinitePrimeField.getInstance(char)
top = uniutil.polynomial({degree: 1}, coeffring=basefield)
for seed in range(degree - 1):
for const in range(1, char):
coeffs = [const] + arith1.expand(seed, 2)
cand = uniutil.polynomial(enumerate(coeffs),
coeffring=basefield) + top
if cand.isirreducible():
_log.debug(cand.order.format(cand))
return cand
for subdeg in range(degree):
subseedbound = char**subdeg
for subseed in range(subseedbound + 1, char * subseedbound):
if not subseed % char:
continue
seed = subseed + cardinality
cand = uniutil.polynomial(enumerate(
arith1.expand(seed, cardinality)),
coeffring=basefield)
if cand.isirreducible():
return cand
def testDivPoly(self):
E = elliptic.EC([3, 4], 101)
F101 = finitefield.FinitePrimeField.getInstance(E.ch)
D = ({-1:uniutil.polynomial({0:-1}, F101),
0:uniutil.polynomial({}, F101),
1:uniutil.polynomial({0:1}, F101),
2:uniutil.polynomial({0:2}, F101),
3:uniutil.polynomial({0:92, 1:48, 2:18, 4:3}, F101),
4:uniutil.polynomial({0:188, 1:10, 2:22, 3:118, 4:60, 6:4}, F101),
5:uniutil.polynomial({0:48, 1:58, 2:53, 3:60, 4:28, 5:93, 6:79,
7:52, 8:65, 9:5, 10:85, 12:5}, F101),
6:uniutil.polynomial({0:18, 1:24, 2:88, 3:32, 4:128, 5:44, 6:152,
7:56, 8:84, 9:192, 10:174, 12:114, 13:124,
14:28, 16:6}, F101),
7:uniutil.polynomial({0:94, 1:77, 2:87, 3:65, 4:97, 5:45, 6:80,
7:22, 8:44, 9:76, 10:5, 11:49, 12:49, 13:74,
14:76, 15:53, 16:69, 17:47, 18:63, 19:70,
20:78, 21:20, 22:15, 24:7}, F101),
8:uniutil.polynomial({0:32, 1:100, 2:58, 3:20, 4:124, 5:160, 6:82,
7:132, 8:158, 9:96, 10:154, 11:106, 12:134,
13:140, 14:10, 15:36, 16:72, 17:56, 18:116,
19:190, 20:134, 21:182, 22:74, 23:186, 24:50,
25:186, 26:122, 27:68, 28:136, 30:8}, F101)},
[2, 3, 5, 7])
self.assertEqual(D, E.divPoly([]))
def _primitive_polynomial(char, degree):
"""
Return a primitive polynomial of self.degree.
REF: Lidl & Niederreiter, Introduction to finite fields and
their applications.
"""
cardinality = char**degree
basefield = FinitePrimeField.getInstance(char)
const = basefield.primitive_element()
if degree & 1:
const = -const
cand = uniutil.polynomial({0: const, degree: basefield.one}, basefield)
maxorder = factor_misc.FactoredInteger((cardinality - 1) // (char - 1))
var = uniutil.polynomial({1: basefield.one}, basefield)
while not (cand.isirreducible() and all(
pow(var,
int(maxorder) // p, cand).degree() > 0
for p in maxorder.prime_divisors())):
# randomly modify the polynomial
deg = bigrandom.randrange(1, degree)
coeff = basefield.random_element(1, char)
cand += uniutil.polynomial({deg: coeff}, basefield)
_log.debug(cand.order.format(cand))
return cand
def setUp(self):
"""
define a class using DivisionProvider
"""
R = rational.Rational
Q = rational.theRationalField
self.up1 = up1 = uniutil.polynomial([(1, R(1))], coeffring=Q)
self.u = uniutil.polynomial([(0, up1), (3, up1)], up1.getRing())
self.v = uniutil.polynomial([(0, -up1)], up1.getRing())
def testShortSeq(self):
"""
sequence has less dimension
"""
F5 = finitefield.FinitePrimeField.getInstance(5)
f5 = F5.createElement
ann = uniutil.polynomial({1: 1}, F5)
self.assertEqual(ann, linrec.minpoly(map(f5, [3, 0, 0, 0, 0, 0])))
ann = uniutil.polynomial({2: 1}, F5)
self.assertEqual(ann, linrec.minpoly(map(f5, [3, 1, 0, 0, 0, 0])))
def testAddition(self):
Z = self.Z
f = uniutil.polynomial(enumerate(range(1, 6)), Z)
g = uniutil.polynomial(enumerate(range(7, 10)), Z)
h = uniutil.polynomial(enumerate([8, 10, 12, 4, 5]), Z)
self.assertEqual(h, f + g)
self.assertTrue(isinstance(f + g, uniutil.IntegerPolynomial))
# sf bug # 1937925
f2 = uniutil.polynomial(enumerate([2, 2, 3, 4, 5]), Z)
self.assertEqual(f2, f + 1)
self.assertEqual(f2, 1 + f)
def testResultant(self):
Z = rational.theIntegerRing
I = rational.Integer
f = uniutil.polynomial(enumerate(map(I, range(5))), coeffring=Z)
g = uniutil.polynomial(enumerate(map(I, range(7, 10))), coeffring=Z)
self.assertEqual(0, f.resultant(f * g))
h1 = uniutil.polynomial(enumerate(map(I, [-2, 0, 0, 1])), coeffring=Z)
h2 = uniutil.polynomial(enumerate([Z.zero, Z.one]), coeffring=Z)
self.assertEqual(2, h1.resultant(h2))
t = uniutil.polynomial(enumerate(map(I, range(7, 0, -1))), coeffring=Z)
self.assertEqual(2**16 * 7**4, t.resultant(t.differentiate()))
def setUp(self):
"""
set up some polynomials
"""
self.f1 = uniutil.polynomial(enumerate([3, 6, 81, 1]), Z)
self.f2 = uniutil.polynomial(enumerate([1, 81, 6, 3]), Z)
self.f3 = uniutil.polynomial(enumerate([37, 6, 18, 1]), Z)
self.f4 = uniutil.polynomial(enumerate([91, 7, 14, 1]), Z)
# f5 = (x - 6)(x - 5)...x(x + 1)(x + 2) - 1
self.f5 = uniutil.polynomial(
enumerate([1439, -1368, -1324, 1638, -231, -252, 114, -18, 1]), Z)
def testNonPrimitive(self):
f1 = uniutil.polynomial(enumerate([3, 6]), Z)
f2 = uniutil.polynomial(enumerate([5, 4, 1]), Z)
f3 = uniutil.polynomial(enumerate([-1, 3]), Z)
f = f1**3 * f2**2 * f3
r = zassenhaus.integerpolynomialfactorization(f)
self.assertTrue(isinstance(r, list))
self.assertEqual(4, len(r), r)
self.assertTrue(isinstance(r[0][0], uniutil.IntegerPolynomial))
self.assertTrue(isinstance(r[1][0], uniutil.IntegerPolynomial))
self.assertTrue(isinstance(r[2][0], uniutil.IntegerPolynomial))
self.assertTrue(isinstance(r[3][0], uniutil.IntegerPolynomial))
self.assertEqual(f, r[0][0]**r[0][1] * r[1][0]**r[1][1] * r[2][0]**r[2][1] * r[3][0]**r[3][1])
def setUp(self):
"""
define a class using DivisionProvider
"""
Polynomial = multiutil.UniqueFactorizationDomainPolynomial
R = rational.Rational
Q = rational.theRationalField
self.f1 = f1 = Polynomial([((3, 1), R(1)), ((0, 1), R(1))], coeffring=Q)
f2 = Polynomial([((0, 1), R(-1))], coeffring=Q)
self.fn = uniutil.polynomial([(0, f1), (3, f2)], coeffring=f1.getRing())
self.fz = Polynomial([((0, 3, 1), R(1)), ((3, 0, 1), R(-1)), ((0, 0, 1), R(1))], coeffring=Q)
u1 = uniutil.polynomial([(1, R(1))], coeffring=Q)
u2 = uniutil.polynomial([(1, R(1))], coeffring=Q)
self.u = uniutil.polynomial([(0, u1), (3, u2)], u1.getRing())
def testWeilPairing(self):
# this example was refered to Washington.
e = elliptic.EC([0, 2], 7)
P = [5, 1]
Q = [0, 3]
R = e.WeilPairing(3, P, Q)
self.assertEqual(finitefield.FinitePrimeFieldElement(2, 7), R)
# test case of extension field, characteristic 7
p = 7
r = 11
F = finitefield.FinitePrimeField(p)
PX = uniutil.polynomial({0:3,1:3,2:2,3:1,4:4,5:1,6:1,10:1},F)
Fx = finitefield.FiniteExtendedField(p,PX)
E = elliptic.EC([F.one,-F.one],F)
Ex = elliptic.EC([Fx.one,-Fx.one],Fx)
P = [3,6]
assert E.whetherOn(P)
assert Ex.whetherOn(P)
assert E.mul(11,P) == E.infpoint
Qxcoord = Fx.createElement(6*7**9+7**8+7**6+6*7**3+6*7**2+7+6)
Qycoord = Fx.createElement(3*7**9+6*7**8+4*7**7+2*7**6+5*7**4+5*7**3+7**2+7+3)
Q = [Qxcoord,Qycoord]
assert Ex.whetherOn(Q)
assert Ex.mul(11,Q) == Ex.infpoint
w = Ex.WeilPairing(11, P, Q)
Wp = Fx.createElement(7**9 + 5*7**8 + 4*7**7 + 2*7**5 + 7**4 + 6*7**2)
assert w == Wp
def Dedekind(minpoly_coeff, p, e):
"""
Return (finished or not, an order)
the Dedekind criterion
Arguments:
- minpoly_coeff: (integer) list of the minimal polynomial of theta.
- p, e: p**e divides the discriminant of the minimal polynomial.
"""
n = len(minpoly_coeff) - 1 # degree of the minimal polynomial
m, uniq = _factor_minpoly_modp(minpoly_coeff, p)
omega = _default_omega(n)
if m == 0:
return True, omega
minpoly = uniutil.polynomial(enumerate(minpoly_coeff), Z)
v = [_coeff_list(uniq, n)]
shift = uniq
for i in range(1, m):
shift = shift.upshift_degree(1).pseudo_mod(minpoly)
v.append(_coeff_list(shift, n))
updater = ModuleWithDenominator(v, p)
return (m + 1 > e), updater + omega
def testDiscriminant(self):
Q = rational.theRationalField
rat = rational.Rational
a, b, c = rat(2, 7), rat(5, 14), rat(1, 7)
q1 = uniutil.polynomial(enumerate([c, b, a]), Q)
d = b**2 - 4 * a * c
self.assertEqual(d, q1.discriminant())
def testIrreducible(self):
f = uniutil.polynomial(enumerate([12, 6, 1]), Z)
r = zassenhaus.zassenhaus(f)
self.assertTrue(isinstance(r, list), r)
self.assertEqual(1, len(r))
self.assertTrue(isinstance(r[0], uniutil.UniqueFactorizationDomainPolynomial))
self.assertEqual(f, r[0])
def padic_factorization(f):
"""
padic_factorization(f) -> p, factors
Return a prime p and a p-adic factorization of given integer
coefficient squarefree polynomial f. The result factors have
integer coefficients, injected from F_p to its minimum absolute
representation. The prime is chosen to be 1) f is still squarefree
mod p, 2) the number of factors is not greater than with the
successive prime.
"""
num_factors = f.degree()
stock = None
for p in prime.generator():
fmodp = uniutil.polynomial(f.terms(),
finitefield.FinitePrimeField.getInstance(p))
if f.degree() > fmodp.degree():
continue
g = fmodp.getRing().gcd(fmodp, fmodp.differentiate())
if g.degree() == 0:
fp_factors = fmodp.factor()
if (not stock) or num_factors > len(fp_factors):
stock = (p, fp_factors)
if len(fp_factors) == 1:
return stock
num_factors = len(fp_factors)
else:
break
p = stock[0]
fp_factors = []
for (fp_factor, m) in stock[1]:
assert m == 1 # since squarefree
fp_factors.append(minimum_absolute_injection(fp_factor))
return (p, fp_factors)
def qpoly(coeffs):
"""
Return a rational coefficient polynomial constructed from given
coeffs. The coeffs is a list of coefficients in ascending order.
"""
terms = [(i, rational.Rational(c)) for (i, c) in enumerate(coeffs)]
return uniutil.polynomial(terms, rational.theRationalField)
def Dedekind(minpoly_coeff, p, e):
"""
Return (finished or not, an order)
the Dedekind criterion
Arguments:
- minpoly_coeff: (integer) list of the minimal polynomial of theta.
- p, e: p**e divides the discriminant of the minimal polynomial.
"""
n = len(minpoly_coeff) - 1 # degree of the minimal polynomial
m, uniq = _factor_minpoly_modp(minpoly_coeff, p)
omega = _default_omega(n)
if m == 0:
return True, omega
minpoly = uniutil.polynomial(enumerate(minpoly_coeff), Z)
v = [_coeff_list(uniq, n)]
shift = uniq
for i in range(1, m):
shift = shift.upshift_degree(1).pseudo_mod(minpoly)
v.append(_coeff_list(shift, n))
updater = ModuleWithDenominator(v, p)
return (m + 1 > e), updater + omega
def fppoly(coeffs, p):
"""
Return a Z_p coefficient polynomial constructed from given
coeffs. The coeffs is a list of coefficients in ascending order.
"""
return uniutil.polynomial(enumerate(coeffs),
finitefield.FinitePrimeField(p))
def qpoly(coeffs):
"""
Return a rational coefficient polynomial constructed from given
coeffs. The coeffs is a list of coefficients in ascending order.
"""
terms = [(i, rational.Rational(c)) for (i, c) in enumerate(coeffs)]
return uniutil.polynomial(terms, rational.theRationalField)
def _mod_p(poly, p):
"""
Return modulo p reduction of given integer coefficient polynomial.
"""
coeff = {}
for d, c in poly:
coeff[d] = finitefield.FinitePrimeFieldElement(c, p)
return uniutil.polynomial(poly, finitefield.FinitePrimeField.getInstance(p))
def testAtti(self):
"""
This test case is taken from the paper of Atti et al.
"""
Q = rational.theRationalField
rat = rational.Rational
ann = uniutil.polynomial(enumerate([0, 1, 1, 1]), Q)
self.assertEqual(ann, linrec.minpoly(map(rat, [1, 2, 7, -9, 2, 7])))
def _mod_p(poly, p):
"""
Return modulo p reduction of given integer coefficient polynomial.
"""
coeff = {}
for d, c in poly:
coeff[d] = finitefield.FinitePrimeFieldElement(c, p)
return uniutil.polynomial(poly, finitefield.FinitePrimeField.getInstance(p))
def testRegular(self):
f = uniutil.polynomial(enumerate([12, 7, 1]), Z)
r = zassenhaus.padic_factorization(f)
self.assertTrue(isinstance(r, tuple))
self.assertEqual(2, len(r))
self.assertTrue(prime.primeq(r[0]))
self.assertTrue(isinstance(r[1], list))
self.assertEqual(2, len(r[1]))
def setUp(self):
self.f = ratfunc.RationalFunction(uniutil.polynomial({
3: 1,
0: 1
}, Z), uniutil.polynomial({
2: 1,
0: -2
}, Z))
self.f2 = self.f
self.f3 = ratfunc.RationalFunction(
uniutil.polynomial({
4: 1,
1: 1
}, Z), uniutil.polynomial({
3: 1,
1: -2
}, Z))
def testRegular(self):
f = uniutil.polynomial(enumerate([12, 7, 1]), Z)
r = zassenhaus.zassenhaus(f)
self.assertTrue(isinstance(r, list))
self.assertEqual(2, len(r), r)
self.assertTrue(isinstance(r[0], uniutil.UniqueFactorizationDomainPolynomial))
self.assertTrue(isinstance(r[1], uniutil.UniqueFactorizationDomainPolynomial))
self.assertEqual(f, r[0] * r[1])
def testAtti_19(self):
"""
testAtti on F19
"""
F19 = finitefield.FinitePrimeField.getInstance(19)
f19 = F19.createElement
ann = uniutil.polynomial(enumerate([0, 1, 1, 1]), F19)
self.assertEqual(ann, linrec.minpoly(map(f19, [1, 2, 7, -9, 2, 7])))
def _min_abs_poly(poly_p):
"""
Return minimal absolute mapping of given F_p coefficient polynomial.
"""
coeff = {}
p = poly_p.getCoefficientRing().char
for d, c in poly_p:
coeff[d] = _pull_back(c, p)
return uniutil.polynomial(coeff, Z)
def _min_abs_poly(poly_p):
"""
Return minimal absolute mapping of given F_p coefficient polynomial.
"""
coeff = {}
p = poly_p.getCoefficientRing().char
for d, c in poly_p:
coeff[d] = _pull_back(c, p)
return uniutil.polynomial(coeff, Z)
def minpoly(firstterms):
"""
Return the minimal polynomial having at most degree n of of the
linearly recurrent sequence whose first 2n terms are given.
"""
field = ring.getRing(firstterms[0])
r_0 = uniutil.polynomial({len(firstterms): field.one}, field)
r_1 = uniutil.polynomial(enumerate(reversed(firstterms)), field)
poly_ring = r_0.getRing()
v_0 = poly_ring.zero
v_1 = poly_ring.one
n = len(firstterms) // 2
while n <= r_1.degree():
q, r = divmod(r_0, r_1)
v_0, v_1 = v_1, v_0 - q * v_1
r_0, r_1 = r_1, r
return v_1.scalar_mul(v_1.leading_coefficient().inverse())
def getCharPoly(self):
"""
Return the characteristic polynomial of self
by compute products of (x-self^{(i)}).
"""
if not hasattr(self, "charpoly"):
Conj = self.getApprox()
P = uniutil.polynomial({0:-Conj[0], 1:1}, ring.getRing(Conj[0]))
for i in range(1, self.degree):
P *= uniutil.polynomial({0:-Conj[i], 1:1},
ring.getRing(Conj[i]))
charcoeff = []
for i in range(self.degree + 1):
if hasattr(P[i], "real"):
charcoeff.append(int(math.floor(P[i].real + 0.5)))
else:
charcoeff.append(int(math.floor(P[i] + 0.5)))
self.charpoly = charcoeff
return self.charpoly
def getCharPoly(self):
"""
Return the characteristic polynomial of self
by compute products of (x-self^{(i)}).
"""
if not hasattr(self, "charpoly"):
Conj = self.getApprox()
P = uniutil.polynomial({0:-Conj[0], 1:1}, ring.getRing(Conj[0]))
for i in range(1, self.degree):
P *= uniutil.polynomial({0:-Conj[i], 1:1},
ring.getRing(Conj[i]))
charcoeff = []
for i in range(self.degree + 1):
if hasattr(P[i], "real"):
charcoeff.append(int(math.floor(P[i].real + 0.5)))
else:
charcoeff.append(int(math.floor(P[i] + 0.5)))
self.charpoly = charcoeff
return self.charpoly
def _zero_polynomial(self):
"""
Return the zero polynomial in the polynomial ring.
"""
if self.number_of_variables == 1:
import nzmath.poly.uniutil as uniutil
return uniutil.polynomial((), self._coefficient_ring)
else:
import nzmath.poly.multiutil as multiutil
return multiutil.polynomial((), coeffring=self._coefficient_ring, number_of_variables=self.number_of_variables)
def testReduceEuclideanPolynomial(self):
whole = poly_ring.PolynomialIdeal(-1, self.zx)
f = uniutil.polynomial([(0, 3), (1, 2)], self.Z)
f_ideal = poly_ring.PolynomialIdeal(f, self.zx)
self.assertFalse(whole.reduce(f))
self.assertTrue(f_ideal.reduce(self.Z.one))
two_generators = poly_ring.PolynomialIdeal([f, self.zx.createElement(5)], self.zx)
self.assertFalse(two_generators.reduce(f))
self.assertTrue(two_generators.reduce(self.Z.one))
def _prepared_polynomial(self, preparation):
"""
Return a polynomial from given preparation, which is suited
for the first argument of uni-/multi-variable polynomials.
"""
if self.number_of_variables == 1:
import nzmath.poly.uniutil as uniutil
return uniutil.polynomial(preparation, self._coefficient_ring)
else:
import nzmath.poly.multiutil as multiutil
return multiutil.polynomial(preparation, self._coefficient_ring)
def testSeptic(self):
"""
Test an example: X^7 + 2X^6 + ... + 7X + 8
"""
poly_disc = uniutil.polynomial(enumerate(self.septic),
self.Z).discriminant()
self.assertEqual(-2**16 * 3**12, poly_disc)
result = round2.round2(self.septic)
self.assertTrue(result)
self.assertEqual(2, len(result))
self.assertEqual(-2**12 * 3**10, result[1], result)
def _constant_polynomial(self, seed):
"""
Return a constant polynomial made from a constant seed.
seed should not be zero.
"""
if self.number_of_variables == 1:
import nzmath.poly.uniutil as uniutil
return uniutil.polynomial({0: seed}, self._coefficient_ring)
else:
import nzmath.poly.multiutil as multiutil
const = (0,) * self.number_of_variables
return multiutil.polynomial({const: seed}, self._coefficient_ring)
def _factor_minpoly_modp(minpoly_coeff, p):
"""
Factor theminpoly modulo p, and return two values in a tuple.
We call gcd(square factors mod p, difference of minpoly and its modp) Z.
1) degree of Z
2) (minpoly mod p) / Z
"""
Fp = finitefield.FinitePrimeField.getInstance(p)
theminpoly_p = uniutil.polynomial([(d, Fp.createElement(c)) for (d, c) in enumerate(minpoly_coeff)], Fp)
modpfactors = theminpoly_p.factor()
mini_p = arith1.product([t for (t, e) in modpfactors])
quot_p = theminpoly_p.exact_division(mini_p)
mini = _min_abs_poly(mini_p)
quot = _min_abs_poly(quot_p)
minpoly = uniutil.polynomial(enumerate(minpoly_coeff), Z)
f_p = _mod_p((mini * quot - minpoly).scalar_exact_division(p), p)
gcd = f_p.getRing().gcd
common_p = gcd(gcd(mini_p, quot_p), f_p) # called Z
uniq_p = theminpoly_p // common_p
uniq = _min_abs_poly(uniq_p)
return common_p.degree(), uniq
def extgcdp(f, g, p):
"""
extgcdp(f,g,p) -> u,v,w
Find u,v,w such that f*u + g*v = w = gcd(f,g) mod p.
"""
zpz = intresidue.IntegerResidueClassRing.getInstance(p)
f_zpz = uniutil.polynomial(f, zpz)
g_zpz = uniutil.polynomial(g, zpz)
zero, one = f_zpz.getRing().zero, f_zpz.getRing().one
u, v, w, x, y, z = one, zero, f_zpz, zero, one, g_zpz
while z:
q = w // z
u, v, w, x, y, z = x, y, z, u - q*x, v - q*y, w - q*z
if w.degree() == 0 and w[0] != zpz.one:
u = u.scalar_exact_division(w[0]) # u / w
v = v.scalar_exact_division(w[0]) # v / w
w = w.getRing().one # w / w
u = minimum_absolute_injection(u)
v = minimum_absolute_injection(v)
w = minimum_absolute_injection(w)
return u, v, w
def _primitive_polynomial(char, degree):
"""
Return a primitive polynomial of self.degree.
REF: Lidl & Niederreiter, Introduction to finite fields and
their applications.
"""
cardinality = char ** degree
basefield = FinitePrimeField.getInstance(char)
const = basefield.primitive_element()
if degree % 2:
const = -const
cand = uniutil.polynomial({0:const, degree:basefield.one}, basefield)
maxorder = factor_misc.FactoredInteger((cardinality - 1) // (char - 1))
var = uniutil.polynomial({1:basefield.one}, basefield)
while not (cand.isirreducible() and
all(pow(var, int(maxorder) // p, cand).degree() > 0 for p in maxorder.prime_divisors())):
# randomly modify the polynomial
deg = bigrandom.randrange(1, degree)
coeff = basefield.random_element(1, char)
cand += uniutil.polynomial({deg:coeff}, basefield)
_log.debug(cand.order.format(cand))
return cand
def _small_irriducible(char, degree):
"""
Return an irreducible polynomial of self.degree with a small
number of non-zero coefficients.
"""
cardinality = char ** degree
basefield = FinitePrimeField.getInstance(char)
top = uniutil.polynomial({degree: 1}, coeffring=basefield)
for seed in range(degree - 1):
for const in range(1, char):
coeffs = [const] + arith1.expand(seed, 2)
cand = uniutil.polynomial(enumerate(coeffs), coeffring=basefield) + top
if cand.isirreducible():
_log.debug(cand.order.format(cand))
return cand
for subdeg in range(degree):
subseedbound = char ** subdeg
for subseed in range(subseedbound + 1, char * subseedbound):
if not subseed % char:
continue
seed = subseed + cardinality
cand = uniutil.polynomial(enumerate(arith1.expand(seed, cardinality)), coeffring=basefield)
if cand.isirreducible():
return cand
def nest(self, outer, coeffring):
"""
Nest the polynomial by extracting outer variable at the given
position.
"""
combined = {}
if self.number_of_variables == 2:
itercoeff = lambda coeff: [(i[0], c) for (i, c) in coeff]
poly = uniutil.polynomial
polyring = poly_ring.PolynomialRing.getInstance(coeffring)
elif self.number_of_variables >= 3:
itercoeff = lambda coeff: coeff
poly = self.__class__
polyring = poly_ring.PolynomialRing.getInstance(coeffring, self.number_of_variables - 1)
else:
raise TypeError("number of variable is not multiple")
for index, coeff in self.combine_similar_terms(outer):
combined[index] = poly(itercoeff(coeff), coeffring=coeffring)
return uniutil.polynomial(combined, coeffring=polyring)
def _SimMethod(g, initials=None, newtoninitial=None, repeat=250):
"""
Return zeros of a polynomial given as a list.
- g is the list of the polynomial coefficient in ascending order.
- initial (optional) is a list of initial approximations of zeros.
- newtoninitial (optional) is an initial value for Newton method to
obtain an initial approximations of zeros if 'initial' is not given.
- repeat (optional) is the number of iteration. The default is 250.
"""
if initials is None:
if newtoninitial:
z = _initialize(g, newtoninitial)
else:
z = _initialize(g)
else:
z = initials
f = uniutil.polynomial(enumerate(g), imaginary.theComplexField)
deg = f.degree()
df = f.differentiate()
value_list = [f(z[i]) for i in range(deg)]
for loop in range(repeat):
sigma_list = [0] * deg
for i in range(deg):
if not value_list[i]:
continue
sigma = 0
for j in range(i):
sigma += 1 / (z[i] - z[j])
for j in range(i+1, deg):
sigma += 1 / (z[i] - z[j])
sigma_list[i] = sigma
for i in range(deg):
if not value_list[i]:
continue
ratio = value_list[i] / df(z[i])
z[i] -= ratio / (1 - ratio*sigma_list[i])
value_list[i] = f(z[i])
return z
def _p_maximal(p, e, minpoly_coeff):
"""
Return p-maximal basis with some related informations.
The arguments:
p: the prime
e: the exponent
minpoly_coeff: (intefer) list of coefficients of the minimal
polynomial of theta
"""
# Apply the Dedekind criterion
finished, omega = Dedekind(minpoly_coeff, p, e)
if finished:
_log.info("Dedekind(%d)" % p)
return omega
# main loop to construct p-maximal order
minpoly = uniutil.polynomial(enumerate(minpoly_coeff), Z)
theminpoly = minpoly.to_field_polynomial()
n = theminpoly.degree()
q = p ** (arith1.log(n, p) + 1)
while True:
# Ip: radical of pO
# Ip = <alpha>, l = dim Ip/pO (essential part of Ip)
alpha, l = _p_radical(omega, p, q, minpoly, n)
# instead of step 9 big matrix,
# Kida's LN section 2.2
# Up = {x in Ip | xIp \subset pIp} = <zeta> + p<omega>
zeta = _p_module(alpha, l, p, theminpoly)
if zeta.rank == 0:
# no new basis is found
break
# new order
# 1/p Up = 1/p<zeta> + <omega>
omega2 = zeta / p + omega
if all(o1 == o2 for o1, o2 in zip(omega.basis, omega2.basis)):
break
omega = omega2
# now <omega> is p-maximal.
return omega
def round2(minpoly_coeff):
"""
Return integral basis of the ring of integers of a field with its
discriminant. The field is given by a list of integers, which is
a polynomial of generating element theta. The polynomial ought to
be monic, in other word, the generating element ought to be an
algebraic integer.
The integral basis will be given as a list of rational vectors
with respect to theta. (In other functions, bases are returned in
the same fashion.)
"""
minpoly_int = uniutil.polynomial(enumerate(minpoly_coeff), Z)
d = minpoly_int.discriminant()
squarefactors = _prepare_squarefactors(d)
omega = _default_omega(minpoly_int.degree())
for p, e in squarefactors:
_log.debug("p = %d" % p)
omega = omega + _p_maximal(p, e, minpoly_coeff)
G = omega.determinant()
return omega.get_rationals(), d * G**2
def _kernel_of_qpow(omega, q, p, minpoly, n):
"""
Return the kernel of q-th powering, which is a linear map over Fp.
q is a power of p which exceeds n.
(omega_j^q (mod theminpoly) = \sum a_i_j omega_i a_i_j in Fp)
"""
omega_poly = omega.get_polynomials()
denom = omega.denominator
theminpoly = minpoly.to_field_polynomial()
field_p = finitefield.FinitePrimeField.getInstance(p)
zero = field_p.zero
qpow = matrix.zeroMatrix(n, n, field_p) # Fp matrix
for j in range(n):
a_j = [zero] * n
omega_poly_j = uniutil.polynomial(enumerate(omega.basis[j]), Z)
omega_j_qpow = pow(omega_poly_j, q, minpoly)
redundancy = gcd.gcd(omega_j_qpow.content(), denom ** q)
omega_j_qpow = omega_j_qpow.coefficients_map(lambda c: c // redundancy)
essential = denom ** q // redundancy
while omega_j_qpow:
i = omega_j_qpow.degree()
a_ji = int(omega_j_qpow[i] / (omega_poly[i][i] * essential))
omega_j_qpow -= a_ji * (omega_poly[i] * essential)
if omega_j_qpow.degree() < i:
a_j[i] = field_p.createElement(a_ji)
else:
_log.debug("%s / %d" % (str(omega_j_qpow), essential))
_log.debug("j = %d, a_ji = %s" % (j, a_ji))
raise ValueError("omega is not a basis")
qpow.setColumn(j + 1, a_j)
result = qpow.kernel()
if result is None:
_log.debug("(_k_q): trivial kernel")
return matrix.zeroMatrix(n, 1, field_p)
else:
return result
def minimum_absolute_injection(f):
"""
minimum_absolute_injection(f) -> F
Return an integer coefficient polynomial F by injection of a Z/pZ
coefficient polynomial f with sending each coefficient to minimum
absolute representatives.
"""
coefficientRing = f.getCoefficientRing()
if isinstance(coefficientRing, intresidue.IntegerResidueClassRing):
p = coefficientRing.m
elif isinstance(coefficientRing, finitefield.FinitePrimeField):
p = coefficientRing.getCharacteristic()
else:
raise TypeError("unknown ring (%s)" % repr(coefficientRing))
half = p // 2
g = {}
for i, c in f.iterterms():
if c.n > half:
g[i] = c.n - p
else:
g[i] = c.n
return uniutil.polynomial(g, rational.theIntegerRing)
def padic_factorization(f):
"""
padic_factorization(f) -> p, factors
Return a prime p and a p-adic factorization of given integer
coefficient squarefree polynomial f. The result factors have
integer coefficients, injected from F_p to its minimum absolute
representation. The prime is chosen to be 1) f is still squarefree
mod p, 2) the number of factors is not greater than with the
successive prime.
"""
num_factors = f.degree()
stock = None
for p in prime.generator():
fmodp = uniutil.polynomial(
f.terms(),
finitefield.FinitePrimeField.getInstance(p))
if f.degree() > fmodp.degree():
continue
g = fmodp.getRing().gcd(fmodp,
fmodp.differentiate())
if g.degree() == 0:
fp_factors = fmodp.factor()
if not stock or num_factors > len(fp_factors):
stock = (p, fp_factors)
if len(fp_factors) == 1:
return stock
num_factors = len(fp_factors)
else:
break
p = stock[0]
fp_factors = []
for (fp_factor, m) in stock[1]:
assert m == 1 # since squarefree
fp_factors.append(minimum_absolute_injection(fp_factor))
return (p, fp_factors)
def fppoly(coeffs, p):
"""
Return a Z_p coefficient polynomial constructed from given
coeffs. The coeffs is a list of coefficients in ascending order.
"""
return uniutil.polynomial(enumerate(coeffs), finitefield.FinitePrimeField(p))
except ValueError, e:
print e.message
print
m = matrix.Matrix(2, 2, [1, 0, 1, 0], f2)
print m
print
v = matrix.Matrix(2, 1, [1, 1], f2)
print v
print
print m.inverseImage(v)
print
f2 = finitefield.FinitePrimeField(2)
P = polyring.PolynomialRing(f2)
x = P.createElement(polynomial([(1, 1)], f2))
def T(A, j):
p = A.coeff_ring.getCharacteristic()
phi = lambda A: (x * A + matrix.unitMatrix(A.row, A.coeff_ring)).determinant()
return phi(A)[p**j]
A = matrix.Matrix(2, 2, [1, 0, 1, 0], f2)
print T(A, 1)
print
#A = matrix.Matrix(4, 4, [2, 1, 1, 1, 2, 1, 2, 1, 3, 2, 2, 1, 0, 1, 2, 1], R)
A = random_matrix(8, 3, f2)
print "Rank", A.rank()
try:
(L, U, P) = A.LUPDecomposition()
def _rational_polynomial(coeffs):
"""
Return rational polynomial with given coefficients in ascending
order.
"""
return uniutil.polynomial(enumerate(coeffs), Q)
def zpoly(coeffs):
"""
Return an integer coefficient polynomial constructed from given
coeffs. The coeffs is a list of coefficients in ascending order.
"""
return uniutil.polynomial(enumerate(coeffs), rational.theIntegerRing)
def affine_multiple_method(lhs, field):
"""
Find and return a root of the equation lhs = 0 by brute force
search in the given field. If there is no root in the field,
ValueError is raised.
The first argument lhs is a univariate polynomial with
coefficients in a finite field. The second argument field is
an extension field of the field of coefficients of lhs.
Affine multiple A(X) is $\sum_{i=0}^{n} a_i X^{q^i} - a$ for some
a_i's and a in the coefficient field of lhs, which is a multiple
of the lhs.
"""
polynomial_ring = lhs.getRing()
coeff_field = lhs.getCoefficientRing()
q = card(coeff_field)
n = lhs.degree()
# residues = [x, x^q, x^{q^2}, ..., x^{q^{n-1}}]
residues = [lhs.mod(polynomial_ring.one.term_mul((1, 1)))] # x
for i in range(1, n):
residues.append(pow(residues[-1], q, lhs)) # x^{q^i}
# find a linear relation among residues and a constant
coeff_matrix = matrix.createMatrix(n, n, [coeff_field.zero] * (n**2), coeff_field)
for j, residue in enumerate(residues):
for i in range(residue.degree() + 1):
coeff_matrix[i + 1, j + 1] = residue[i]
constant_components = [coeff_field.one] + [coeff_field.zero] * (n - 1)
constant_vector = vector.Vector(constant_components)
try:
relation_vector, kernel = coeff_matrix.solve(constant_vector)
for j in range(n, 0, -1):
if relation_vector[j]:
constant = relation_vector[j].inverse()
relation = [constant * c for c in relation_vector]
break
except matrix.NoInverseImage:
kernel_matrix = coeff_matrix.kernel()
relation_vector = kernel_matrix[1]
assert type(relation_vector) is vector.Vector
for j in range(n, 0, -1):
if relation_vector[j]:
normalizer = relation_vector[j].inverse()
relation = [normalizer * c for c in relation_vector]
constant = coeff_field.zero
break
# define L(X) = A(X) + constant
coeffs = {}
for i, relation_i in enumerate(relation):
coeffs[q**i] = relation_i
linearized = uniutil.polynomial(coeffs, coeff_field)
# Fq basis [1, X, ..., X^{s-1}]
qbasis = [1]
root = field.createElement(field.char)
s = arith1.log(card(field), q)
qbasis += [root**i for i in range(1, s)]
# represent L as Matrix
lmat = matrix.createMatrix(s, s, field.basefield)
for j, base in enumerate(qbasis):
imagei = linearized(base)
if imagei.getRing() == field.basefield:
lmat[1, j + 1] = imagei
else:
for i, coeff in imagei.rep.iterterms():
if coeff:
lmat[i + 1, j + 1] = coeff
# solve L(X) = the constant
constant_components = [constant] + [coeff_field.zero] * (s - 1)
constant_vector = vector.Vector(constant_components)
solution, kernel = lmat.solve(constant_vector)
assert lmat * solution == constant_vector
solutions = [solution]
for v in kernel:
for i in range(card(field.basefield)):
solutions.append(solution + i * v)
# roots of A(X) contains the solutions of lhs = 0
for t in bigrange.multirange([(card(field.basefield),)] * len(kernel)):
affine_root_vector = solution
for i, ti in enumerate(t):
affine_root_vector += ti * kernel[i]
affine_root = field.zero
for i, ai in enumerate(affine_root_vector):
affine_root += ai * qbasis[i]
if not lhs(affine_root):
return affine_root
raise ValueError("no root found")
