"""Basic tools for dense recursive polynomials in ``K[x]`` or ``K[X]``. """
from __future__ import print_function, division
from sympy import oo
from sympy.core import igcd
from sympy.core.compatibility import range
from sympy.polys.monomials import monomial_min, monomial_div
from sympy.polys.orderings import monomial_key
import random
def poly_LC(f, K):
"""
Return leading coefficient of ``f``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import poly_LC
>>> poly_LC([], ZZ)
0
>>> poly_LC([ZZ(1), ZZ(2), ZZ(3)], ZZ)
1
"""
if not f:
return K.zero
else:
return f[0]
def poly_TC(f, K):
"""
Return trailing coefficient of ``f``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import poly_TC
>>> poly_TC([], ZZ)
0
>>> poly_TC([ZZ(1), ZZ(2), ZZ(3)], ZZ)
3
"""
if not f:
return K.zero
else:
return f[-1]
dup_LC = dmp_LC = poly_LC
dup_TC = dmp_TC = poly_TC
[docs]def dmp_ground_LC(f, u, K):
"""
Return the ground leading coefficient.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_ground_LC
>>> f = ZZ.map([[[1], [2, 3]]])
>>> dmp_ground_LC(f, 2, ZZ)
1
"""
while u:
f = dmp_LC(f, K)
u -= 1
return dup_LC(f, K)
[docs]def dmp_ground_TC(f, u, K):
"""
Return the ground trailing coefficient.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_ground_TC
>>> f = ZZ.map([[[1], [2, 3]]])
>>> dmp_ground_TC(f, 2, ZZ)
3
"""
while u:
f = dmp_TC(f, K)
u -= 1
return dup_TC(f, K)
[docs]def dmp_true_LT(f, u, K):
"""
Return the leading term ``c * x_1**n_1 ... x_k**n_k``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_true_LT
>>> f = ZZ.map([[4], [2, 0], [3, 0, 0]])
>>> dmp_true_LT(f, 1, ZZ)
((2, 0), 4)
"""
monom = []
while u:
monom.append(len(f) - 1)
f, u = f[0], u - 1
if not f:
monom.append(0)
else:
monom.append(len(f) - 1)
return tuple(monom), dup_LC(f, K)
def dup_degree(f):
"""
Return the leading degree of ``f`` in ``K[x]``.
Note that the degree of 0 is negative infinity (the SymPy object -oo).
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dup_degree
>>> f = ZZ.map([1, 2, 0, 3])
>>> dup_degree(f)
3
"""
if not f:
return -oo
return len(f) - 1
[docs]def dmp_degree(f, u):
"""
Return the leading degree of ``f`` in ``x_0`` in ``K[X]``.
Note that the degree of 0 is negative infinity (the SymPy object -oo).
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_degree
>>> dmp_degree([[[]]], 2)
-oo
>>> f = ZZ.map([[2], [1, 2, 3]])
>>> dmp_degree(f, 1)
1
"""
if dmp_zero_p(f, u):
return -oo
else:
return len(f) - 1
def _rec_degree_in(g, v, i, j):
"""Recursive helper function for :func:`dmp_degree_in`."""
if i == j:
return dmp_degree(g, v)
v, i = v - 1, i + 1
return max([ _rec_degree_in(c, v, i, j) for c in g ])
[docs]def dmp_degree_in(f, j, u):
"""
Return the leading degree of ``f`` in ``x_j`` in ``K[X]``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_degree_in
>>> f = ZZ.map([[2], [1, 2, 3]])
>>> dmp_degree_in(f, 0, 1)
1
>>> dmp_degree_in(f, 1, 1)
2
"""
if not j:
return dmp_degree(f, u)
if j < 0 or j > u:
raise IndexError("0 <= j <= %s expected, got %s" % (u, j))
return _rec_degree_in(f, u, 0, j)
def _rec_degree_list(g, v, i, degs):
"""Recursive helper for :func:`dmp_degree_list`."""
degs[i] = max(degs[i], dmp_degree(g, v))
if v > 0:
v, i = v - 1, i + 1
for c in g:
_rec_degree_list(c, v, i, degs)
[docs]def dmp_degree_list(f, u):
"""
Return a list of degrees of ``f`` in ``K[X]``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_degree_list
>>> f = ZZ.map([[1], [1, 2, 3]])
>>> dmp_degree_list(f, 1)
(1, 2)
"""
degs = [-oo]*(u + 1)
_rec_degree_list(f, u, 0, degs)
return tuple(degs)
def dup_strip(f):
"""
Remove leading zeros from ``f`` in ``K[x]``.
Examples
========
>>> from sympy.polys.densebasic import dup_strip
>>> dup_strip([0, 0, 1, 2, 3, 0])
[1, 2, 3, 0]
"""
if not f or f[0]:
return f
i = 0
for cf in f:
if cf:
break
else:
i += 1
return f[i:]
[docs]def dmp_strip(f, u):
"""
Remove leading zeros from ``f`` in ``K[X]``.
Examples
========
>>> from sympy.polys.densebasic import dmp_strip
>>> dmp_strip([[], [0, 1, 2], [1]], 1)
[[0, 1, 2], [1]]
"""
if not u:
return dup_strip(f)
if dmp_zero_p(f, u):
return f
i, v = 0, u - 1
for c in f:
if not dmp_zero_p(c, v):
break
else:
i += 1
if i == len(f):
return dmp_zero(u)
else:
return f[i:]
def _rec_validate(f, g, i, K):
"""Recursive helper for :func:`dmp_validate`."""
if type(g) is not list:
if K is not None and not K.of_type(g):
raise TypeError("%s in %s in not of type %s" % (g, f, K.dtype))
return set([i - 1])
elif not g:
return set([i])
else:
levels = set([])
for c in g:
levels |= _rec_validate(f, c, i + 1, K)
return levels
def _rec_strip(g, v):
"""Recursive helper for :func:`_rec_strip`."""
if not v:
return dup_strip(g)
w = v - 1
return dmp_strip([ _rec_strip(c, w) for c in g ], v)
[docs]def dmp_validate(f, K=None):
"""
Return the number of levels in ``f`` and recursively strip it.
Examples
========
>>> from sympy.polys.densebasic import dmp_validate
>>> dmp_validate([[], [0, 1, 2], [1]])
([[1, 2], [1]], 1)
>>> dmp_validate([[1], 1])
Traceback (most recent call last):
...
ValueError: invalid data structure for a multivariate polynomial
"""
levels = _rec_validate(f, f, 0, K)
u = levels.pop()
if not levels:
return _rec_strip(f, u), u
else:
raise ValueError(
"invalid data structure for a multivariate polynomial")
[docs]def dup_reverse(f):
"""
Compute ``x**n * f(1/x)``, i.e.: reverse ``f`` in ``K[x]``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dup_reverse
>>> f = ZZ.map([1, 2, 3, 0])
>>> dup_reverse(f)
[3, 2, 1]
"""
return dup_strip(list(reversed(f)))
def dup_copy(f):
"""
Create a new copy of a polynomial ``f`` in ``K[x]``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dup_copy
>>> f = ZZ.map([1, 2, 3, 0])
>>> dup_copy([1, 2, 3, 0])
[1, 2, 3, 0]
"""
return list(f)
[docs]def dmp_copy(f, u):
"""
Create a new copy of a polynomial ``f`` in ``K[X]``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_copy
>>> f = ZZ.map([[1], [1, 2]])
>>> dmp_copy(f, 1)
[[1], [1, 2]]
"""
if not u:
return list(f)
v = u - 1
return [ dmp_copy(c, v) for c in f ]
def dup_to_tuple(f):
"""
Convert `f` into a tuple.
This is needed for hashing. This is similar to dup_copy().
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dup_copy
>>> f = ZZ.map([1, 2, 3, 0])
>>> dup_copy([1, 2, 3, 0])
[1, 2, 3, 0]
"""
return tuple(f)
[docs]def dmp_to_tuple(f, u):
"""
Convert `f` into a nested tuple of tuples.
This is needed for hashing. This is similar to dmp_copy().
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_to_tuple
>>> f = ZZ.map([[1], [1, 2]])
>>> dmp_to_tuple(f, 1)
((1,), (1, 2))
"""
if not u:
return tuple(f)
v = u - 1
return tuple(dmp_to_tuple(c, v) for c in f)
def dup_normal(f, K):
"""
Normalize univariate polynomial in the given domain.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dup_normal
>>> dup_normal([0, 1.5, 2, 3], ZZ)
[1, 2, 3]
"""
return dup_strip([ K.normal(c) for c in f ])
[docs]def dmp_normal(f, u, K):
"""
Normalize a multivariate polynomial in the given domain.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_normal
>>> dmp_normal([[], [0, 1.5, 2]], 1, ZZ)
[[1, 2]]
"""
if not u:
return dup_normal(f, K)
v = u - 1
return dmp_strip([ dmp_normal(c, v, K) for c in f ], u)
def dup_convert(f, K0, K1):
"""
Convert the ground domain of ``f`` from ``K0`` to ``K1``.
Examples
========
>>> from sympy.polys.rings import ring
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dup_convert
>>> R, x = ring("x", ZZ)
>>> dup_convert([R(1), R(2)], R.to_domain(), ZZ)
[1, 2]
>>> dup_convert([ZZ(1), ZZ(2)], ZZ, R.to_domain())
[1, 2]
"""
if K0 is not None and K0 == K1:
return f
else:
return dup_strip([ K1.convert(c, K0) for c in f ])
[docs]def dmp_convert(f, u, K0, K1):
"""
Convert the ground domain of ``f`` from ``K0`` to ``K1``.
Examples
========
>>> from sympy.polys.rings import ring
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_convert
>>> R, x = ring("x", ZZ)
>>> dmp_convert([[R(1)], [R(2)]], 1, R.to_domain(), ZZ)
[[1], [2]]
>>> dmp_convert([[ZZ(1)], [ZZ(2)]], 1, ZZ, R.to_domain())
[[1], [2]]
"""
if not u:
return dup_convert(f, K0, K1)
if K0 is not None and K0 == K1:
return f
v = u - 1
return dmp_strip([ dmp_convert(c, v, K0, K1) for c in f ], u)
def dup_from_sympy(f, K):
"""
Convert the ground domain of ``f`` from SymPy to ``K``.
Examples
========
>>> from sympy import S
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dup_from_sympy
>>> dup_from_sympy([S(1), S(2)], ZZ) == [ZZ(1), ZZ(2)]
True
"""
return dup_strip([ K.from_sympy(c) for c in f ])
[docs]def dmp_from_sympy(f, u, K):
"""
Convert the ground domain of ``f`` from SymPy to ``K``.
Examples
========
>>> from sympy import S
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_from_sympy
>>> dmp_from_sympy([[S(1)], [S(2)]], 1, ZZ) == [[ZZ(1)], [ZZ(2)]]
True
"""
if not u:
return dup_from_sympy(f, K)
v = u - 1
return dmp_strip([ dmp_from_sympy(c, v, K) for c in f ], u)
def dup_nth(f, n, K):
"""
Return the ``n``-th coefficient of ``f`` in ``K[x]``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dup_nth
>>> f = ZZ.map([1, 2, 3])
>>> dup_nth(f, 0, ZZ)
3
>>> dup_nth(f, 4, ZZ)
0
"""
if n < 0:
raise IndexError("'n' must be non-negative, got %i" % n)
elif n >= len(f):
return K.zero
else:
return f[dup_degree(f) - n]
[docs]def dmp_nth(f, n, u, K):
"""
Return the ``n``-th coefficient of ``f`` in ``K[x]``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_nth
>>> f = ZZ.map([[1], [2], [3]])
>>> dmp_nth(f, 0, 1, ZZ)
[3]
>>> dmp_nth(f, 4, 1, ZZ)
[]
"""
if n < 0:
raise IndexError("'n' must be non-negative, got %i" % n)
elif n >= len(f):
return dmp_zero(u - 1)
else:
return f[dmp_degree(f, u) - n]
[docs]def dmp_ground_nth(f, N, u, K):
"""
Return the ground ``n``-th coefficient of ``f`` in ``K[x]``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_ground_nth
>>> f = ZZ.map([[1], [2, 3]])
>>> dmp_ground_nth(f, (0, 1), 1, ZZ)
2
"""
v = u
for n in N:
if n < 0:
raise IndexError("`n` must be non-negative, got %i" % n)
elif n >= len(f):
return K.zero
else:
d = dmp_degree(f, v)
if d == -oo:
d = -1
f, v = f[d - n], v - 1
return f
[docs]def dmp_zero_p(f, u):
"""
Return ``True`` if ``f`` is zero in ``K[X]``.
Examples
========
>>> from sympy.polys.densebasic import dmp_zero_p
>>> dmp_zero_p([[[[[]]]]], 4)
True
>>> dmp_zero_p([[[[[1]]]]], 4)
False
"""
while u:
if len(f) != 1:
return False
f = f[0]
u -= 1
return not f
[docs]def dmp_zero(u):
"""
Return a multivariate zero.
Examples
========
>>> from sympy.polys.densebasic import dmp_zero
>>> dmp_zero(4)
[[[[[]]]]]
"""
r = []
for i in range(u):
r = [r]
return r
[docs]def dmp_one_p(f, u, K):
"""
Return ``True`` if ``f`` is one in ``K[X]``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_one_p
>>> dmp_one_p([[[ZZ(1)]]], 2, ZZ)
True
"""
return dmp_ground_p(f, K.one, u)
[docs]def dmp_one(u, K):
"""
Return a multivariate one over ``K``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_one
>>> dmp_one(2, ZZ)
[[[1]]]
"""
return dmp_ground(K.one, u)
[docs]def dmp_ground_p(f, c, u):
"""
Return True if ``f`` is constant in ``K[X]``.
Examples
========
>>> from sympy.polys.densebasic import dmp_ground_p
>>> dmp_ground_p([[[3]]], 3, 2)
True
>>> dmp_ground_p([[[4]]], None, 2)
True
"""
if c is not None and not c:
return dmp_zero_p(f, u)
while u:
if len(f) != 1:
return False
f = f[0]
u -= 1
if c is None:
return len(f) <= 1
else:
return f == [c]
[docs]def dmp_ground(c, u):
"""
Return a multivariate constant.
Examples
========
>>> from sympy.polys.densebasic import dmp_ground
>>> dmp_ground(3, 5)
[[[[[[3]]]]]]
>>> dmp_ground(1, -1)
1
"""
if not c:
return dmp_zero(u)
for i in range(u + 1):
c = [c]
return c
[docs]def dmp_zeros(n, u, K):
"""
Return a list of multivariate zeros.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_zeros
>>> dmp_zeros(3, 2, ZZ)
[[[[]]], [[[]]], [[[]]]]
>>> dmp_zeros(3, -1, ZZ)
[0, 0, 0]
"""
if not n:
return []
if u < 0:
return [K.zero]*n
else:
return [ dmp_zero(u) for i in range(n) ]
[docs]def dmp_grounds(c, n, u):
"""
Return a list of multivariate constants.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_grounds
>>> dmp_grounds(ZZ(4), 3, 2)
[[[[4]]], [[[4]]], [[[4]]]]
>>> dmp_grounds(ZZ(4), 3, -1)
[4, 4, 4]
"""
if not n:
return []
if u < 0:
return [c]*n
else:
return [ dmp_ground(c, u) for i in range(n) ]
[docs]def dmp_negative_p(f, u, K):
"""
Return ``True`` if ``LC(f)`` is negative.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_negative_p
>>> dmp_negative_p([[ZZ(1)], [-ZZ(1)]], 1, ZZ)
False
>>> dmp_negative_p([[-ZZ(1)], [ZZ(1)]], 1, ZZ)
True
"""
return K.is_negative(dmp_ground_LC(f, u, K))
[docs]def dmp_positive_p(f, u, K):
"""
Return ``True`` if ``LC(f)`` is positive.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_positive_p
>>> dmp_positive_p([[ZZ(1)], [-ZZ(1)]], 1, ZZ)
True
>>> dmp_positive_p([[-ZZ(1)], [ZZ(1)]], 1, ZZ)
False
"""
return K.is_positive(dmp_ground_LC(f, u, K))
def dup_from_dict(f, K):
"""
Create a ``K[x]`` polynomial from a ``dict``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dup_from_dict
>>> dup_from_dict({(0,): ZZ(7), (2,): ZZ(5), (4,): ZZ(1)}, ZZ)
[1, 0, 5, 0, 7]
>>> dup_from_dict({}, ZZ)
[]
"""
if not f:
return []
n, h = max(f.keys()), []
if type(n) is int:
for k in range(n, -1, -1):
h.append(f.get(k, K.zero))
else:
(n,) = n
for k in range(n, -1, -1):
h.append(f.get((k,), K.zero))
return dup_strip(h)
def dup_from_raw_dict(f, K):
"""
Create a ``K[x]`` polynomial from a raw ``dict``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dup_from_raw_dict
>>> dup_from_raw_dict({0: ZZ(7), 2: ZZ(5), 4: ZZ(1)}, ZZ)
[1, 0, 5, 0, 7]
"""
if not f:
return []
n, h = max(f.keys()), []
for k in range(n, -1, -1):
h.append(f.get(k, K.zero))
return dup_strip(h)
[docs]def dmp_from_dict(f, u, K):
"""
Create a ``K[X]`` polynomial from a ``dict``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_from_dict
>>> dmp_from_dict({(0, 0): ZZ(3), (0, 1): ZZ(2), (2, 1): ZZ(1)}, 1, ZZ)
[[1, 0], [], [2, 3]]
>>> dmp_from_dict({}, 0, ZZ)
[]
"""
if not u:
return dup_from_dict(f, K)
if not f:
return dmp_zero(u)
coeffs = {}
for monom, coeff in f.items():
head, tail = monom[0], monom[1:]
if head in coeffs:
coeffs[head][tail] = coeff
else:
coeffs[head] = { tail: coeff }
n, v, h = max(coeffs.keys()), u - 1, []
for k in range(n, -1, -1):
coeff = coeffs.get(k)
if coeff is not None:
h.append(dmp_from_dict(coeff, v, K))
else:
h.append(dmp_zero(v))
return dmp_strip(h, u)
def dup_to_dict(f, K=None, zero=False):
"""
Convert ``K[x]`` polynomial to a ``dict``.
Examples
========
>>> from sympy.polys.densebasic import dup_to_dict
>>> dup_to_dict([1, 0, 5, 0, 7])
{(0,): 7, (2,): 5, (4,): 1}
>>> dup_to_dict([])
{}
"""
if not f and zero:
return {(0,): K.zero}
n, result = len(f) - 1, {}
for k in range(0, n + 1):
if f[n - k]:
result[(k,)] = f[n - k]
return result
def dup_to_raw_dict(f, K=None, zero=False):
"""
Convert a ``K[x]`` polynomial to a raw ``dict``.
Examples
========
>>> from sympy.polys.densebasic import dup_to_raw_dict
>>> dup_to_raw_dict([1, 0, 5, 0, 7])
{0: 7, 2: 5, 4: 1}
"""
if not f and zero:
return {0: K.zero}
n, result = len(f) - 1, {}
for k in range(0, n + 1):
if f[n - k]:
result[k] = f[n - k]
return result
[docs]def dmp_to_dict(f, u, K=None, zero=False):
"""
Convert a ``K[X]`` polynomial to a ``dict````.
Examples
========
>>> from sympy.polys.densebasic import dmp_to_dict
>>> dmp_to_dict([[1, 0], [], [2, 3]], 1)
{(0, 0): 3, (0, 1): 2, (2, 1): 1}
>>> dmp_to_dict([], 0)
{}
"""
if not u:
return dup_to_dict(f, K, zero=zero)
if dmp_zero_p(f, u) and zero:
return {(0,)*(u + 1): K.zero}
n, v, result = dmp_degree(f, u), u - 1, {}
if n == -oo:
n = -1
for k in range(0, n + 1):
h = dmp_to_dict(f[n - k], v)
for exp, coeff in h.items():
result[(k,) + exp] = coeff
return result
[docs]def dmp_swap(f, i, j, u, K):
"""
Transform ``K[..x_i..x_j..]`` to ``K[..x_j..x_i..]``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_swap
>>> f = ZZ.map([[[2], [1, 0]], []])
>>> dmp_swap(f, 0, 1, 2, ZZ)
[[[2], []], [[1, 0], []]]
>>> dmp_swap(f, 1, 2, 2, ZZ)
[[[1], [2, 0]], [[]]]
>>> dmp_swap(f, 0, 2, 2, ZZ)
[[[1, 0]], [[2, 0], []]]
"""
if i < 0 or j < 0 or i > u or j > u:
raise IndexError("0 <= i < j <= %s expected" % u)
elif i == j:
return f
F, H = dmp_to_dict(f, u), {}
for exp, coeff in F.items():
H[exp[:i] + (exp[j],) +
exp[i + 1:j] +
(exp[i],) + exp[j + 1:]] = coeff
return dmp_from_dict(H, u, K)
[docs]def dmp_permute(f, P, u, K):
"""
Return a polynomial in ``K[x_{P(1)},..,x_{P(n)}]``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_permute
>>> f = ZZ.map([[[2], [1, 0]], []])
>>> dmp_permute(f, [1, 0, 2], 2, ZZ)
[[[2], []], [[1, 0], []]]
>>> dmp_permute(f, [1, 2, 0], 2, ZZ)
[[[1], []], [[2, 0], []]]
"""
F, H = dmp_to_dict(f, u), {}
for exp, coeff in F.items():
new_exp = [0]*len(exp)
for e, p in zip(exp, P):
new_exp[p] = e
H[tuple(new_exp)] = coeff
return dmp_from_dict(H, u, K)
[docs]def dmp_nest(f, l, K):
"""
Return a multivariate value nested ``l``-levels.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_nest
>>> dmp_nest([[ZZ(1)]], 2, ZZ)
[[[[1]]]]
"""
if not isinstance(f, list):
return dmp_ground(f, l)
for i in range(l):
f = [f]
return f
[docs]def dmp_raise(f, l, u, K):
"""
Return a multivariate polynomial raised ``l``-levels.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_raise
>>> f = ZZ.map([[], [1, 2]])
>>> dmp_raise(f, 2, 1, ZZ)
[[[[]]], [[[1]], [[2]]]]
"""
if not l:
return f
if not u:
if not f:
return dmp_zero(l)
k = l - 1
return [ dmp_ground(c, k) for c in f ]
v = u - 1
return [ dmp_raise(c, l, v, K) for c in f ]
def dup_deflate(f, K):
"""
Map ``x**m`` to ``y`` in a polynomial in ``K[x]``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dup_deflate
>>> f = ZZ.map([1, 0, 0, 1, 0, 0, 1])
>>> dup_deflate(f, ZZ)
(3, [1, 1, 1])
"""
if dup_degree(f) <= 0:
return 1, f
g = 0
for i in range(len(f)):
if not f[-i - 1]:
continue
g = igcd(g, i)
if g == 1:
return 1, f
return g, f[::g]
[docs]def dmp_deflate(f, u, K):
"""
Map ``x_i**m_i`` to ``y_i`` in a polynomial in ``K[X]``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_deflate
>>> f = ZZ.map([[1, 0, 0, 2], [], [3, 0, 0, 4]])
>>> dmp_deflate(f, 1, ZZ)
((2, 3), [[1, 2], [3, 4]])
"""
if dmp_zero_p(f, u):
return (1,)*(u + 1), f
F = dmp_to_dict(f, u)
B = [0]*(u + 1)
for M in F.keys():
for i, m in enumerate(M):
B[i] = igcd(B[i], m)
for i, b in enumerate(B):
if not b:
B[i] = 1
B = tuple(B)
if all(b == 1 for b in B):
return B, f
H = {}
for A, coeff in F.items():
N = [ a // b for a, b in zip(A, B) ]
H[tuple(N)] = coeff
return B, dmp_from_dict(H, u, K)
def dup_multi_deflate(polys, K):
"""
Map ``x**m`` to ``y`` in a set of polynomials in ``K[x]``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dup_multi_deflate
>>> f = ZZ.map([1, 0, 2, 0, 3])
>>> g = ZZ.map([4, 0, 0])
>>> dup_multi_deflate((f, g), ZZ)
(2, ([1, 2, 3], [4, 0]))
"""
G = 0
for p in polys:
if dup_degree(p) <= 0:
return 1, polys
g = 0
for i in range(len(p)):
if not p[-i - 1]:
continue
g = igcd(g, i)
if g == 1:
return 1, polys
G = igcd(G, g)
return G, tuple([ p[::G] for p in polys ])
[docs]def dmp_multi_deflate(polys, u, K):
"""
Map ``x_i**m_i`` to ``y_i`` in a set of polynomials in ``K[X]``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_multi_deflate
>>> f = ZZ.map([[1, 0, 0, 2], [], [3, 0, 0, 4]])
>>> g = ZZ.map([[1, 0, 2], [], [3, 0, 4]])
>>> dmp_multi_deflate((f, g), 1, ZZ)
((2, 1), ([[1, 0, 0, 2], [3, 0, 0, 4]], [[1, 0, 2], [3, 0, 4]]))
"""
if not u:
M, H = dup_multi_deflate(polys, K)
return (M,), H
F, B = [], [0]*(u + 1)
for p in polys:
f = dmp_to_dict(p, u)
if not dmp_zero_p(p, u):
for M in f.keys():
for i, m in enumerate(M):
B[i] = igcd(B[i], m)
F.append(f)
for i, b in enumerate(B):
if not b:
B[i] = 1
B = tuple(B)
if all(b == 1 for b in B):
return B, polys
H = []
for f in F:
h = {}
for A, coeff in f.items():
N = [ a // b for a, b in zip(A, B) ]
h[tuple(N)] = coeff
H.append(dmp_from_dict(h, u, K))
return B, tuple(H)
def dup_inflate(f, m, K):
"""
Map ``y`` to ``x**m`` in a polynomial in ``K[x]``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dup_inflate
>>> f = ZZ.map([1, 1, 1])
>>> dup_inflate(f, 3, ZZ)
[1, 0, 0, 1, 0, 0, 1]
"""
if m <= 0:
raise IndexError("'m' must be positive, got %s" % m)
if m == 1 or not f:
return f
result = [f[0]]
for coeff in f[1:]:
result.extend([K.zero]*(m - 1))
result.append(coeff)
return result
def _rec_inflate(g, M, v, i, K):
"""Recursive helper for :func:`dmp_inflate`."""
if not v:
return dup_inflate(g, M[i], K)
if M[i] <= 0:
raise IndexError("all M[i] must be positive, got %s" % M[i])
w, j = v - 1, i + 1
g = [ _rec_inflate(c, M, w, j, K) for c in g ]
result = [g[0]]
for coeff in g[1:]:
for _ in range(1, M[i]):
result.append(dmp_zero(w))
result.append(coeff)
return result
[docs]def dmp_inflate(f, M, u, K):
"""
Map ``y_i`` to ``x_i**k_i`` in a polynomial in ``K[X]``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_inflate
>>> f = ZZ.map([[1, 2], [3, 4]])
>>> dmp_inflate(f, (2, 3), 1, ZZ)
[[1, 0, 0, 2], [], [3, 0, 0, 4]]
"""
if not u:
return dup_inflate(f, M[0], K)
if all(m == 1 for m in M):
return f
else:
return _rec_inflate(f, M, u, 0, K)
[docs]def dmp_exclude(f, u, K):
"""
Exclude useless levels from ``f``.
Return the levels excluded, the new excluded ``f``, and the new ``u``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_exclude
>>> f = ZZ.map([[[1]], [[1], [2]]])
>>> dmp_exclude(f, 2, ZZ)
([2], [[1], [1, 2]], 1)
"""
if not u or dmp_ground_p(f, None, u):
return [], f, u
J, F = [], dmp_to_dict(f, u)
for j in range(0, u + 1):
for monom in F.keys():
if monom[j]:
break
else:
J.append(j)
if not J:
return [], f, u
f = {}
for monom, coeff in F.items():
monom = list(monom)
for j in reversed(J):
del monom[j]
f[tuple(monom)] = coeff
u -= len(J)
return J, dmp_from_dict(f, u, K), u
[docs]def dmp_include(f, J, u, K):
"""
Include useless levels in ``f``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_include
>>> f = ZZ.map([[1], [1, 2]])
>>> dmp_include(f, [2], 1, ZZ)
[[[1]], [[1], [2]]]
"""
if not J:
return f
F, f = dmp_to_dict(f, u), {}
for monom, coeff in F.items():
monom = list(monom)
for j in J:
monom.insert(j, 0)
f[tuple(monom)] = coeff
u += len(J)
return dmp_from_dict(f, u, K)
[docs]def dmp_inject(f, u, K, front=False):
"""
Convert ``f`` from ``K[X][Y]`` to ``K[X,Y]``.
Examples
========
>>> from sympy.polys.rings import ring
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_inject
>>> R, x,y = ring("x,y", ZZ)
>>> dmp_inject([R(1), x + 2], 0, R.to_domain())
([[[1]], [[1], [2]]], 2)
>>> dmp_inject([R(1), x + 2], 0, R.to_domain(), front=True)
([[[1]], [[1, 2]]], 2)
"""
f, h = dmp_to_dict(f, u), {}
v = K.ngens - 1
for f_monom, g in f.items():
g = g.to_dict()
for g_monom, c in g.items():
if front:
h[g_monom + f_monom] = c
else:
h[f_monom + g_monom] = c
w = u + v + 1
return dmp_from_dict(h, w, K.dom), w
[docs]def dmp_eject(f, u, K, front=False):
"""
Convert ``f`` from ``K[X,Y]`` to ``K[X][Y]``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_eject
>>> dmp_eject([[[1]], [[1], [2]]], 2, ZZ['x', 'y'])
[1, x + 2]
"""
f, h = dmp_to_dict(f, u), {}
n = K.ngens
v = u - K.ngens + 1
for monom, c in f.items():
if front:
g_monom, f_monom = monom[:n], monom[n:]
else:
g_monom, f_monom = monom[-n:], monom[:-n]
if f_monom in h:
h[f_monom][g_monom] = c
else:
h[f_monom] = {g_monom: c}
for monom, c in h.items():
h[monom] = K(c)
return dmp_from_dict(h, v - 1, K)
def dup_terms_gcd(f, K):
"""
Remove GCD of terms from ``f`` in ``K[x]``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dup_terms_gcd
>>> f = ZZ.map([1, 0, 1, 0, 0])
>>> dup_terms_gcd(f, ZZ)
(2, [1, 0, 1])
"""
if dup_TC(f, K) or not f:
return 0, f
i = 0
for c in reversed(f):
if not c:
i += 1
else:
break
return i, f[:-i]
[docs]def dmp_terms_gcd(f, u, K):
"""
Remove GCD of terms from ``f`` in ``K[X]``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_terms_gcd
>>> f = ZZ.map([[1, 0], [1, 0, 0], [], []])
>>> dmp_terms_gcd(f, 1, ZZ)
((2, 1), [[1], [1, 0]])
"""
if dmp_ground_TC(f, u, K) or dmp_zero_p(f, u):
return (0,)*(u + 1), f
F = dmp_to_dict(f, u)
G = monomial_min(*list(F.keys()))
if all(g == 0 for g in G):
return G, f
f = {}
for monom, coeff in F.items():
f[monomial_div(monom, G)] = coeff
return G, dmp_from_dict(f, u, K)
def _rec_list_terms(g, v, monom):
"""Recursive helper for :func:`dmp_list_terms`."""
d, terms = dmp_degree(g, v), []
if not v:
for i, c in enumerate(g):
if not c:
continue
terms.append((monom + (d - i,), c))
else:
w = v - 1
for i, c in enumerate(g):
terms.extend(_rec_list_terms(c, w, monom + (d - i,)))
return terms
[docs]def dmp_list_terms(f, u, K, order=None):
"""
List all non-zero terms from ``f`` in the given order ``order``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_list_terms
>>> f = ZZ.map([[1, 1], [2, 3]])
>>> dmp_list_terms(f, 1, ZZ)
[((1, 1), 1), ((1, 0), 1), ((0, 1), 2), ((0, 0), 3)]
>>> dmp_list_terms(f, 1, ZZ, order='grevlex')
[((1, 1), 1), ((1, 0), 1), ((0, 1), 2), ((0, 0), 3)]
"""
def sort(terms, O):
return sorted(terms, key=lambda term: O(term[0]), reverse=True)
terms = _rec_list_terms(f, u, ())
if not terms:
return [((0,)*(u + 1), K.zero)]
if order is None:
return terms
else:
return sort(terms, monomial_key(order))
def dup_apply_pairs(f, g, h, args, K):
"""
Apply ``h`` to pairs of coefficients of ``f`` and ``g``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dup_apply_pairs
>>> h = lambda x, y, z: 2*x + y - z
>>> dup_apply_pairs([1, 2, 3], [3, 2, 1], h, (1,), ZZ)
[4, 5, 6]
"""
n, m = len(f), len(g)
if n != m:
if n > m:
g = [K.zero]*(n - m) + g
else:
f = [K.zero]*(m - n) + f
result = []
for a, b in zip(f, g):
result.append(h(a, b, *args))
return dup_strip(result)
[docs]def dmp_apply_pairs(f, g, h, args, u, K):
"""
Apply ``h`` to pairs of coefficients of ``f`` and ``g``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dmp_apply_pairs
>>> h = lambda x, y, z: 2*x + y - z
>>> dmp_apply_pairs([[1], [2, 3]], [[3], [2, 1]], h, (1,), 1, ZZ)
[[4], [5, 6]]
"""
if not u:
return dup_apply_pairs(f, g, h, args, K)
n, m, v = len(f), len(g), u - 1
if n != m:
if n > m:
g = dmp_zeros(n - m, v, K) + g
else:
f = dmp_zeros(m - n, v, K) + f
result = []
for a, b in zip(f, g):
result.append(dmp_apply_pairs(a, b, h, args, v, K))
return dmp_strip(result, u)
def dup_slice(f, m, n, K):
"""Take a continuous subsequence of terms of ``f`` in ``K[x]``. """
k = len(f)
if k >= m:
M = k - m
else:
M = 0
if k >= n:
N = k - n
else:
N = 0
f = f[N:M]
if not f:
return []
else:
return f + [K.zero]*m
[docs]def dmp_slice(f, m, n, u, K):
"""Take a continuous subsequence of terms of ``f`` in ``K[X]``. """
return dmp_slice_in(f, m, n, 0, u, K)
def dmp_slice_in(f, m, n, j, u, K):
"""Take a continuous subsequence of terms of ``f`` in ``x_j`` in ``K[X]``. """
if j < 0 or j > u:
raise IndexError("-%s <= j < %s expected, got %s" % (u, u, j))
if not u:
return dup_slice(f, m, n, K)
f, g = dmp_to_dict(f, u), {}
for monom, coeff in f.items():
k = monom[j]
if k < m or k >= n:
monom = monom[:j] + (0,) + monom[j + 1:]
if monom in g:
g[monom] += coeff
else:
g[monom] = coeff
return dmp_from_dict(g, u, K)
[docs]def dup_random(n, a, b, K):
"""
Return a polynomial of degree ``n`` with coefficients in ``[a, b]``.
Examples
========
>>> from sympy.polys.domains import ZZ
>>> from sympy.polys.densebasic import dup_random
>>> dup_random(3, -10, 10, ZZ) #doctest: +SKIP
[-2, -8, 9, -4]
"""
f = [ K.convert(random.randint(a, b)) for _ in range(0, n + 1) ]
while not f[0]:
f[0] = K.convert(random.randint(a, b))
return f
