Source code for sympy.polys.densearith

"""Arithmetics for dense recursive polynomials in ``K[x]`` or ``K[X]``. """

from __future__ import print_function, division

from sympy.polys.densebasic import (
    dup_slice,
    dup_LC, dmp_LC,
    dup_degree, dmp_degree,
    dup_normal,
    dup_strip, dmp_strip,
    dmp_zero_p, dmp_zero,
    dmp_one_p, dmp_one,
    dmp_ground, dmp_zeros)

from sympy.polys.polyerrors import (ExactQuotientFailed, PolynomialDivisionFailed)
from sympy.core.compatibility import xrange

def dup_add_term(f, c, i, K):
    """
    Add ``c*x**i`` to ``f`` in ``K[x]``.

    Examples
    ========

    >>> from sympy.polys import ring, ZZ
    >>> R, x = ring("x", ZZ)

    >>> R.dup_add_term(x**2 - 1, ZZ(2), 4)
    2*x**4 + x**2 - 1

    """
    if not c:
        return f

    n = len(f)
    m = n - i - 1

    if i == n - 1:
        return dup_strip([f[0] + c] + f[1:])
    else:
        if i >= n:
            return [c] + [K.zero]*(i - n) + f
        else:
            return f[:m] + [f[m] + c] + f[m + 1:]


[docs]def dmp_add_term(f, c, i, u, K): """ Add ``c(x_2..x_u)*x_0**i`` to ``f`` in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x,y = ring("x,y", ZZ) >>> R.dmp_add_term(x*y + 1, 2, 2) 2*x**2 + x*y + 1 """ if not u: return dup_add_term(f, c, i, K) v = u - 1 if dmp_zero_p(c, v): return f n = len(f) m = n - i - 1 if i == n - 1: return dmp_strip([dmp_add(f[0], c, v, K)] + f[1:], u) else: if i >= n: return [c] + dmp_zeros(i - n, v, K) + f else: return f[:m] + [dmp_add(f[m], c, v, K)] + f[m + 1:]
def dup_sub_term(f, c, i, K): """ Subtract ``c*x**i`` from ``f`` in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_sub_term(2*x**4 + x**2 - 1, ZZ(2), 4) x**2 - 1 """ if not c: return f n = len(f) m = n - i - 1 if i == n - 1: return dup_strip([f[0] - c] + f[1:]) else: if i >= n: return [-c] + [K.zero]*(i - n) + f else: return f[:m] + [f[m] - c] + f[m + 1:]
[docs]def dmp_sub_term(f, c, i, u, K): """ Subtract ``c(x_2..x_u)*x_0**i`` from ``f`` in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x,y = ring("x,y", ZZ) >>> R.dmp_sub_term(2*x**2 + x*y + 1, 2, 2) x*y + 1 """ if not u: return dup_add_term(f, -c, i, K) v = u - 1 if dmp_zero_p(c, v): return f n = len(f) m = n - i - 1 if i == n - 1: return dmp_strip([dmp_sub(f[0], c, v, K)] + f[1:], u) else: if i >= n: return [dmp_neg(c, v, K)] + dmp_zeros(i - n, v, K) + f else: return f[:m] + [dmp_sub(f[m], c, v, K)] + f[m + 1:]
def dup_mul_term(f, c, i, K): """ Multiply ``f`` by ``c*x**i`` in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_mul_term(x**2 - 1, ZZ(3), 2) 3*x**4 - 3*x**2 """ if not c or not f: return [] else: return [ cf * c for cf in f ] + [K.zero]*i
[docs]def dmp_mul_term(f, c, i, u, K): """ Multiply ``f`` by ``c(x_2..x_u)*x_0**i`` in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x,y = ring("x,y", ZZ) >>> R.dmp_mul_term(x**2*y + x, 3*y, 2) 3*x**4*y**2 + 3*x**3*y """ if not u: return dup_mul_term(f, c, i, K) v = u - 1 if dmp_zero_p(f, u): return f if dmp_zero_p(c, v): return dmp_zero(u) else: return [ dmp_mul(cf, c, v, K) for cf in f ] + dmp_zeros(i, v, K)
def dup_add_ground(f, c, K): """ Add an element of the ground domain to ``f``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_add_ground(x**3 + 2*x**2 + 3*x + 4, ZZ(4)) x**3 + 2*x**2 + 3*x + 8 """ return dup_add_term(f, c, 0, K)
[docs]def dmp_add_ground(f, c, u, K): """ Add an element of the ground domain to ``f``. Examples ======== >>> from sympy.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 dup_sub_ground(f, c, K): """ Subtract an element of the ground domain from ``f``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_sub_ground(x**3 + 2*x**2 + 3*x + 4, ZZ(4)) x**3 + 2*x**2 + 3*x """ return dup_sub_term(f, c, 0, K)
[docs]def dmp_sub_ground(f, c, u, K): """ Subtract an element of the ground domain from ``f``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x,y = ring("x,y", ZZ) >>> R.dmp_sub_ground(x**3 + 2*x**2 + 3*x + 4, ZZ(4)) x**3 + 2*x**2 + 3*x """ return dmp_sub_term(f, dmp_ground(c, u - 1), 0, u, K)
def dup_mul_ground(f, c, K): """ Multiply ``f`` by a constant value in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_mul_ground(x**2 + 2*x - 1, ZZ(3)) 3*x**2 + 6*x - 3 """ if not c or not f: return [] else: return [ cf * c for cf in f ]
[docs]def dmp_mul_ground(f, c, u, K): """ Multiply ``f`` by a constant value in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x,y = ring("x,y", ZZ) >>> R.dmp_mul_ground(2*x + 2*y, ZZ(3)) 6*x + 6*y """ if not u: return dup_mul_ground(f, c, K) v = u - 1 return [ dmp_mul_ground(cf, c, v, K) for cf in f ]
def dup_quo_ground(f, c, K): """ Quotient by a constant in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ, QQ >>> R, x = ring("x", ZZ) >>> R.dup_quo_ground(3*x**2 + 2, ZZ(2)) x**2 + 1 >>> R, x = ring("x", QQ) >>> R.dup_quo_ground(3*x**2 + 2, QQ(2)) 3/2*x**2 + 1 """ if not c: raise ZeroDivisionError('polynomial division') if not f: return f if K.has_Field: return [ K.quo(cf, c) for cf in f ] else: return [ cf // c for cf in f ]
[docs]def dmp_quo_ground(f, c, u, K): """ Quotient by a constant in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ, QQ >>> R, x,y = ring("x,y", ZZ) >>> R.dmp_quo_ground(2*x**2*y + 3*x, ZZ(2)) x**2*y + x >>> R, x,y = ring("x,y", QQ) >>> R.dmp_quo_ground(2*x**2*y + 3*x, QQ(2)) x**2*y + 3/2*x """ if not u: return dup_quo_ground(f, c, K) v = u - 1 return [ dmp_quo_ground(cf, c, v, K) for cf in f ]
def dup_exquo_ground(f, c, K): """ Exact quotient by a constant in ``K[x]``. Examples ======== >>> from sympy.polys import ring, QQ >>> R, x = ring("x", QQ) >>> R.dup_exquo_ground(x**2 + 2, QQ(2)) 1/2*x**2 + 1 """ if not c: raise ZeroDivisionError('polynomial division') if not f: return f return [ K.exquo(cf, c) for cf in f ]
[docs]def dmp_exquo_ground(f, c, u, K): """ Exact quotient by a constant in ``K[X]``. Examples ======== >>> from sympy.polys import ring, QQ >>> R, x,y = ring("x,y", QQ) >>> R.dmp_exquo_ground(x**2*y + 2*x, QQ(2)) 1/2*x**2*y + x """ if not u: return dup_exquo_ground(f, c, K) v = u - 1 return [ dmp_exquo_ground(cf, c, v, K) for cf in f ]
[docs]def dup_lshift(f, n, K): """ Efficiently multiply ``f`` by ``x**n`` in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_lshift(x**2 + 1, 2) x**4 + x**2 """ if not f: return f else: return f + [K.zero]*n
[docs]def dup_rshift(f, n, K): """ Efficiently divide ``f`` by ``x**n`` in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_rshift(x**4 + x**2, 2) x**2 + 1 >>> R.dup_rshift(x**4 + x**2 + 2, 2) x**2 + 1 """ return f[:-n]
def dup_abs(f, K): """ Make all coefficients positive in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_abs(x**2 - 1) x**2 + 1 """ return [ K.abs(coeff) for coeff in f ]
[docs]def dmp_abs(f, u, K): """ Make all coefficients positive in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x,y = ring("x,y", ZZ) >>> R.dmp_abs(x**2*y - x) x**2*y + x """ if not u: return dup_abs(f, K) v = u - 1 return [ dmp_abs(cf, v, K) for cf in f ]
def dup_neg(f, K): """ Negate a polynomial in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_neg(x**2 - 1) -x**2 + 1 """ return [ -coeff for coeff in f ]
[docs]def dmp_neg(f, u, K): """ Negate a polynomial in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x,y = ring("x,y", ZZ) >>> R.dmp_neg(x**2*y - x) -x**2*y + x """ if not u: return dup_neg(f, K) v = u - 1 return [ dmp_neg(cf, v, K) for cf in f ]
def dup_add(f, g, K): """ Add dense polynomials in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_add(x**2 - 1, x - 2) x**2 + x - 3 """ if not f: return g if not g: return f df = dup_degree(f) dg = dup_degree(g) if df == dg: return dup_strip([ a + b for a, b in zip(f, g) ]) else: k = abs(df - dg) if df > dg: h, f = f[:k], f[k:] else: h, g = g[:k], g[k:] return h + [ a + b for a, b in zip(f, g) ]
[docs]def dmp_add(f, g, u, K): """ Add dense polynomials in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x,y = ring("x,y", ZZ) >>> R.dmp_add(x**2 + y, x**2*y + x) x**2*y + x**2 + x + y """ if not u: return dup_add(f, g, K) df = dmp_degree(f, u) if df < 0: return g dg = dmp_degree(g, u) if dg < 0: return f v = u - 1 if df == dg: return dmp_strip([ dmp_add(a, b, v, K) for a, b in zip(f, g) ], u) else: k = abs(df - dg) if df > dg: h, f = f[:k], f[k:] else: h, g = g[:k], g[k:] return h + [ dmp_add(a, b, v, K) for a, b in zip(f, g) ]
def dup_sub(f, g, K): """ Subtract dense polynomials in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_sub(x**2 - 1, x - 2) x**2 - x + 1 """ if not f: return dup_neg(g, K) if not g: return f df = dup_degree(f) dg = dup_degree(g) if df == dg: return dup_strip([ a - b for a, b in zip(f, g) ]) else: k = abs(df - dg) if df > dg: h, f = f[:k], f[k:] else: h, g = dup_neg(g[:k], K), g[k:] return h + [ a - b for a, b in zip(f, g) ]
[docs]def dmp_sub(f, g, u, K): """ Subtract dense polynomials in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x,y = ring("x,y", ZZ) >>> R.dmp_sub(x**2 + y, x**2*y + x) -x**2*y + x**2 - x + y """ if not u: return dup_sub(f, g, K) df = dmp_degree(f, u) if df < 0: return dmp_neg(g, u, K) dg = dmp_degree(g, u) if dg < 0: return f v = u - 1 if df == dg: return dmp_strip([ dmp_sub(a, b, v, K) for a, b in zip(f, g) ], u) else: k = abs(df - dg) if df > dg: h, f = f[:k], f[k:] else: h, g = dmp_neg(g[:k], u, K), g[k:] return h + [ dmp_sub(a, b, v, K) for a, b in zip(f, g) ]
def dup_add_mul(f, g, h, K): """ Returns ``f + g*h`` where ``f, g, h`` are in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_add_mul(x**2 - 1, x - 2, x + 2) 2*x**2 - 5 """ return dup_add(f, dup_mul(g, h, K), K)
[docs]def dmp_add_mul(f, g, h, u, K): """ Returns ``f + g*h`` where ``f, g, h`` are in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x,y = ring("x,y", ZZ) >>> R.dmp_add_mul(x**2 + y, x, x + 2) 2*x**2 + 2*x + y """ return dmp_add(f, dmp_mul(g, h, u, K), u, K)
def dup_sub_mul(f, g, h, K): """ Returns ``f - g*h`` where ``f, g, h`` are in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_sub_mul(x**2 - 1, x - 2, x + 2) 3 """ return dup_sub(f, dup_mul(g, h, K), K)
[docs]def dmp_sub_mul(f, g, h, u, K): """ Returns ``f - g*h`` where ``f, g, h`` are in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x,y = ring("x,y", ZZ) >>> R.dmp_sub_mul(x**2 + y, x, x + 2) -2*x + y """ return dmp_sub(f, dmp_mul(g, h, u, K), u, K)
def dup_mul(f, g, K): """ Multiply dense polynomials in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_mul(x - 2, x + 2) x**2 - 4 """ if f == g: return dup_sqr(f, K) if not (f and g): return [] df = dup_degree(f) dg = dup_degree(g) n = max(df, dg) + 1 if n < 100: h = [] for i in xrange(0, df + dg + 1): coeff = K.zero for j in xrange(max(0, i - dg), min(df, i) + 1): coeff += f[j]*g[i - j] h.append(coeff) return dup_strip(h) else: # Use Karatsuba's algorithm (divide and conquer), see e.g.: # Joris van der Hoeven, Relax But Don't Be Too Lazy, # J. Symbolic Computation, 11 (2002), section 3.1.1. n2 = n//2 fl, gl = dup_slice(f, 0, n2, K), dup_slice(g, 0, n2, K) fh = dup_rshift(dup_slice(f, n2, n, K), n2, K) gh = dup_rshift(dup_slice(g, n2, n, K), n2, K) lo, hi = dup_mul(fl, gl, K), dup_mul(fh, gh, K) mid = dup_mul(dup_add(fl, fh, K), dup_add(gl, gh, K), K) mid = dup_sub(mid, dup_add(lo, hi, K), K) return dup_add(dup_add(lo, dup_lshift(mid, n2, K), K), dup_lshift(hi, 2*n2, K), K)
[docs]def dmp_mul(f, g, u, K): """ Multiply dense polynomials in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x,y = ring("x,y", ZZ) >>> R.dmp_mul(x*y + 1, x) x**2*y + x """ if not u: return dup_mul(f, g, K) if f == g: return dmp_sqr(f, u, K) df = dmp_degree(f, u) if df < 0: return f dg = dmp_degree(g, u) if dg < 0: return g h, v = [], u - 1 for i in xrange(0, df + dg + 1): coeff = dmp_zero(v) for j in xrange(max(0, i - dg), min(df, i) + 1): coeff = dmp_add(coeff, dmp_mul(f[j], g[i - j], v, K), v, K) h.append(coeff) return dmp_strip(h, u)
def dup_sqr(f, K): """ Square dense polynomials in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_sqr(x**2 + 1) x**4 + 2*x**2 + 1 """ df, h = len(f) - 1, [] for i in xrange(0, 2*df + 1): c = K.zero jmin = max(0, i - df) jmax = min(i, df) n = jmax - jmin + 1 jmax = jmin + n // 2 - 1 for j in xrange(jmin, jmax + 1): c += f[j]*f[i - j] c += c if n & 1: elem = f[jmax + 1] c += elem**2 h.append(c) return dup_strip(h)
[docs]def dmp_sqr(f, u, K): """ Square dense polynomials in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x,y = ring("x,y", ZZ) >>> R.dmp_sqr(x**2 + x*y + y**2) x**4 + 2*x**3*y + 3*x**2*y**2 + 2*x*y**3 + y**4 """ if not u: return dup_sqr(f, K) df = dmp_degree(f, u) if df < 0: return f h, v = [], u - 1 for i in xrange(0, 2*df + 1): c = dmp_zero(v) jmin = max(0, i - df) jmax = min(i, df) n = jmax - jmin + 1 jmax = jmin + n // 2 - 1 for j in xrange(jmin, jmax + 1): c = dmp_add(c, dmp_mul(f[j], f[i - j], v, K), v, K) c = dmp_mul_ground(c, K(2), v, K) if n & 1: elem = dmp_sqr(f[jmax + 1], v, K) c = dmp_add(c, elem, v, K) h.append(c) return dmp_strip(h, u)
def dup_pow(f, n, K): """ Raise ``f`` to the ``n``-th power in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_pow(x - 2, 3) x**3 - 6*x**2 + 12*x - 8 """ if not n: return [K.one] if n < 0: raise ValueError("can't raise polynomial to a negative power") if n == 1 or not f or f == [K.one]: return f g = [K.one] while True: n, m = n//2, n if m % 2: g = dup_mul(g, f, K) if not n: break f = dup_sqr(f, K) return g
[docs]def dmp_pow(f, n, u, K): """ Raise ``f`` to the ``n``-th power in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x,y = ring("x,y", ZZ) >>> R.dmp_pow(x*y + 1, 3) x**3*y**3 + 3*x**2*y**2 + 3*x*y + 1 """ if not u: return dup_pow(f, n, K) if not n: return dmp_one(u, K) if n < 0: raise ValueError("can't raise polynomial to a negative power") if n == 1 or dmp_zero_p(f, u) or dmp_one_p(f, u, K): return f g = dmp_one(u, K) while True: n, m = n//2, n if m & 1: g = dmp_mul(g, f, u, K) if not n: break f = dmp_sqr(f, u, K) return g
def dup_pdiv(f, g, K): """ Polynomial pseudo-division in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_pdiv(x**2 + 1, 2*x - 4) (2*x + 4, 20) """ df = dup_degree(f) dg = dup_degree(g) q, r, dr = [], f, df if not g: raise ZeroDivisionError("polynomial division") elif df < dg: return q, r N = df - dg + 1 lc_g = dup_LC(g, K) while True: lc_r = dup_LC(r, K) j, N = dr - dg, N - 1 Q = dup_mul_ground(q, lc_g, K) q = dup_add_term(Q, lc_r, j, K) R = dup_mul_ground(r, lc_g, K) G = dup_mul_term(g, lc_r, j, K) r = dup_sub(R, G, K) _dr, dr = dr, dup_degree(r) if dr < dg: break elif not (dr < _dr): raise PolynomialDivisionFailed(f, g, K) c = lc_g**N q = dup_mul_ground(q, c, K) r = dup_mul_ground(r, c, K) return q, r def dup_prem(f, g, K): """ Polynomial pseudo-remainder in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_prem(x**2 + 1, 2*x - 4) 20 """ df = dup_degree(f) dg = dup_degree(g) r, dr = f, df if not g: raise ZeroDivisionError("polynomial division") elif df < dg: return r N = df - dg + 1 lc_g = dup_LC(g, K) while True: lc_r = dup_LC(r, K) j, N = dr - dg, N - 1 R = dup_mul_ground(r, lc_g, K) G = dup_mul_term(g, lc_r, j, K) r = dup_sub(R, G, K) _dr, dr = dr, dup_degree(r) if dr < dg: break elif not (dr < _dr): raise PolynomialDivisionFailed(f, g, K) return dup_mul_ground(r, lc_g**N, K) def dup_pquo(f, g, K): """ Polynomial exact pseudo-quotient in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_pquo(x**2 - 1, 2*x - 2) 2*x + 2 >>> R.dup_pquo(x**2 + 1, 2*x - 4) 2*x + 4 """ return dup_pdiv(f, g, K)[0] def dup_pexquo(f, g, K): """ Polynomial pseudo-quotient in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_pexquo(x**2 - 1, 2*x - 2) 2*x + 2 >>> R.dup_pexquo(x**2 + 1, 2*x - 4) Traceback (most recent call last): ... ExactQuotientFailed: [2, -4] does not divide [1, 0, 1] """ q, r = dup_pdiv(f, g, K) if not r: return q else: raise ExactQuotientFailed(f, g)
[docs]def dmp_pdiv(f, g, u, K): """ Polynomial pseudo-division in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x,y = ring("x,y", ZZ) >>> R.dmp_pdiv(x**2 + x*y, 2*x + 2) (2*x + 2*y - 2, -4*y + 4) """ if not u: return dup_pdiv(f, g, K) df = dmp_degree(f, u) dg = dmp_degree(g, u) if dg < 0: raise ZeroDivisionError("polynomial division") q, r, dr = dmp_zero(u), f, df if df < dg: return q, r N = df - dg + 1 lc_g = dmp_LC(g, K) while True: lc_r = dmp_LC(r, K) j, N = dr - dg, N - 1 Q = dmp_mul_term(q, lc_g, 0, u, K) q = dmp_add_term(Q, lc_r, j, u, K) R = dmp_mul_term(r, lc_g, 0, u, K) G = dmp_mul_term(g, lc_r, j, u, K) r = dmp_sub(R, G, u, K) _dr, dr = dr, dmp_degree(r, u) if dr < dg: break elif not (dr < _dr): raise PolynomialDivisionFailed(f, g, K) c = dmp_pow(lc_g, N, u - 1, K) q = dmp_mul_term(q, c, 0, u, K) r = dmp_mul_term(r, c, 0, u, K) return q, r
[docs]def dmp_prem(f, g, u, K): """ Polynomial pseudo-remainder in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x,y = ring("x,y", ZZ) >>> R.dmp_prem(x**2 + x*y, 2*x + 2) -4*y + 4 """ if not u: return dup_prem(f, g, K) df = dmp_degree(f, u) dg = dmp_degree(g, u) if dg < 0: raise ZeroDivisionError("polynomial division") r, dr = f, df if df < dg: return r N = df - dg + 1 lc_g = dmp_LC(g, K) while True: lc_r = dmp_LC(r, K) j, N = dr - dg, N - 1 R = dmp_mul_term(r, lc_g, 0, u, K) G = dmp_mul_term(g, lc_r, j, u, K) r = dmp_sub(R, G, u, K) _dr, dr = dr, dmp_degree(r, u) if dr < dg: break elif not (dr < _dr): raise PolynomialDivisionFailed(f, g, K) c = dmp_pow(lc_g, N, u - 1, K) return dmp_mul_term(r, c, 0, u, K)
[docs]def dmp_pquo(f, g, u, K): """ Polynomial exact pseudo-quotient in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x,y = ring("x,y", ZZ) >>> f = x**2 + x*y >>> g = 2*x + 2*y >>> h = 2*x + 2 >>> R.dmp_pquo(f, g) 2*x >>> R.dmp_pquo(f, h) 2*x + 2*y - 2 """ return dmp_pdiv(f, g, u, K)[0]
[docs]def dmp_pexquo(f, g, u, K): """ Polynomial pseudo-quotient in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x,y = ring("x,y", ZZ) >>> f = x**2 + x*y >>> g = 2*x + 2*y >>> h = 2*x + 2 >>> R.dmp_pexquo(f, g) 2*x >>> R.dmp_pexquo(f, h) Traceback (most recent call last): ... ExactQuotientFailed: [[2], [2]] does not divide [[1], [1, 0], []] """ q, r = dmp_pdiv(f, g, u, K) if dmp_zero_p(r, u): return q else: raise ExactQuotientFailed(f, g)
def dup_rr_div(f, g, K): """ Univariate division with remainder over a ring. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_rr_div(x**2 + 1, 2*x - 4) (0, x**2 + 1) """ df = dup_degree(f) dg = dup_degree(g) q, r, dr = [], f, df if not g: raise ZeroDivisionError("polynomial division") elif df < dg: return q, r lc_g = dup_LC(g, K) while True: lc_r = dup_LC(r, K) if lc_r % lc_g: break c = K.exquo(lc_r, lc_g) j = dr - dg q = dup_add_term(q, c, j, K) h = dup_mul_term(g, c, j, K) r = dup_sub(r, h, K) _dr, dr = dr, dup_degree(r) if dr < dg: break elif not (dr < _dr): raise PolynomialDivisionFailed(f, g, K) return q, r
[docs]def dmp_rr_div(f, g, u, K): """ Multivariate division with remainder over a ring. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x,y = ring("x,y", ZZ) >>> R.dmp_rr_div(x**2 + x*y, 2*x + 2) (0, x**2 + x*y) """ if not u: return dup_rr_div(f, g, K) df = dmp_degree(f, u) dg = dmp_degree(g, u) if dg < 0: raise ZeroDivisionError("polynomial division") q, r, dr = dmp_zero(u), f, df if df < dg: return q, r lc_g, v = dmp_LC(g, K), u - 1 while True: lc_r = dmp_LC(r, K) c, R = dmp_rr_div(lc_r, lc_g, v, K) if not dmp_zero_p(R, v): break j = dr - dg q = dmp_add_term(q, c, j, u, K) h = dmp_mul_term(g, c, j, u, K) r = dmp_sub(r, h, u, K) _dr, dr = dr, dmp_degree(r, u) if dr < dg: break elif not (dr < _dr): raise PolynomialDivisionFailed(f, g, K) return q, r
def dup_ff_div(f, g, K): """ Polynomial division with remainder over a field. Examples ======== >>> from sympy.polys import ring, QQ >>> R, x = ring("x", QQ) >>> R.dup_ff_div(x**2 + 1, 2*x - 4) (1/2*x + 1, 5) """ df = dup_degree(f) dg = dup_degree(g) q, r, dr = [], f, df if not g: raise ZeroDivisionError("polynomial division") elif df < dg: return q, r lc_g = dup_LC(g, K) while True: lc_r = dup_LC(r, K) c = K.exquo(lc_r, lc_g) j = dr - dg q = dup_add_term(q, c, j, K) h = dup_mul_term(g, c, j, K) r = dup_sub(r, h, K) _dr, dr = dr, dup_degree(r) if dr < dg: break elif not (dr < _dr): raise PolynomialDivisionFailed(f, g, K) return q, r
[docs]def dmp_ff_div(f, g, u, K): """ Polynomial division with remainder over a field. Examples ======== >>> from sympy.polys import ring, QQ >>> R, x,y = ring("x,y", QQ) >>> R.dmp_ff_div(x**2 + x*y, 2*x + 2) (1/2*x + 1/2*y - 1/2, -y + 1) """ if not u: return dup_ff_div(f, g, K) df = dmp_degree(f, u) dg = dmp_degree(g, u) if dg < 0: raise ZeroDivisionError("polynomial division") q, r, dr = dmp_zero(u), f, df if df < dg: return q, r lc_g, v = dmp_LC(g, K), u - 1 while True: lc_r = dmp_LC(r, K) c, R = dmp_ff_div(lc_r, lc_g, v, K) if not dmp_zero_p(R, v): break j = dr - dg q = dmp_add_term(q, c, j, u, K) h = dmp_mul_term(g, c, j, u, K) r = dmp_sub(r, h, u, K) _dr, dr = dr, dmp_degree(r, u) if dr < dg: break elif not (dr < _dr): raise PolynomialDivisionFailed(f, g, K) return q, r
def dup_div(f, g, K): """ Polynomial division with remainder in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ, QQ >>> R, x = ring("x", ZZ) >>> R.dup_div(x**2 + 1, 2*x - 4) (0, x**2 + 1) >>> R, x = ring("x", QQ) >>> R.dup_div(x**2 + 1, 2*x - 4) (1/2*x + 1, 5) """ if K.has_Field: return dup_ff_div(f, g, K) else: return dup_rr_div(f, g, K) def dup_rem(f, g, K): """ Returns polynomial remainder in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ, QQ >>> R, x = ring("x", ZZ) >>> R.dup_rem(x**2 + 1, 2*x - 4) x**2 + 1 >>> R, x = ring("x", QQ) >>> R.dup_rem(x**2 + 1, 2*x - 4) 5 """ return dup_div(f, g, K)[1] def dup_quo(f, g, K): """ Returns exact polynomial quotient in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ, QQ >>> R, x = ring("x", ZZ) >>> R.dup_quo(x**2 + 1, 2*x - 4) 0 >>> R, x = ring("x", QQ) >>> R.dup_quo(x**2 + 1, 2*x - 4) 1/2*x + 1 """ return dup_div(f, g, K)[0] def dup_exquo(f, g, K): """ Returns polynomial quotient in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_exquo(x**2 - 1, x - 1) x + 1 >>> R.dup_exquo(x**2 + 1, 2*x - 4) Traceback (most recent call last): ... ExactQuotientFailed: [2, -4] does not divide [1, 0, 1] """ q, r = dup_div(f, g, K) if not r: return q else: raise ExactQuotientFailed(f, g)
[docs]def dmp_div(f, g, u, K): """ Polynomial division with remainder in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ, QQ >>> R, x,y = ring("x,y", ZZ) >>> R.dmp_div(x**2 + x*y, 2*x + 2) (0, x**2 + x*y) >>> R, x,y = ring("x,y", QQ) >>> R.dmp_div(x**2 + x*y, 2*x + 2) (1/2*x + 1/2*y - 1/2, -y + 1) """ if K.has_Field: return dmp_ff_div(f, g, u, K) else: return dmp_rr_div(f, g, u, K)
[docs]def dmp_rem(f, g, u, K): """ Returns polynomial remainder in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ, QQ >>> R, x,y = ring("x,y", ZZ) >>> R.dmp_rem(x**2 + x*y, 2*x + 2) x**2 + x*y >>> R, x,y = ring("x,y", QQ) >>> R.dmp_rem(x**2 + x*y, 2*x + 2) -y + 1 """ return dmp_div(f, g, u, K)[1]
[docs]def dmp_quo(f, g, u, K): """ Returns exact polynomial quotient in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ, QQ >>> R, x,y = ring("x,y", ZZ) >>> R.dmp_quo(x**2 + x*y, 2*x + 2) 0 >>> R, x,y = ring("x,y", QQ) >>> R.dmp_quo(x**2 + x*y, 2*x + 2) 1/2*x + 1/2*y - 1/2 """ return dmp_div(f, g, u, K)[0]
[docs]def dmp_exquo(f, g, u, K): """ Returns polynomial quotient in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x,y = ring("x,y", ZZ) >>> f = x**2 + x*y >>> g = x + y >>> h = 2*x + 2 >>> R.dmp_exquo(f, g) x >>> R.dmp_exquo(f, h) Traceback (most recent call last): ... ExactQuotientFailed: [[2], [2]] does not divide [[1], [1, 0], []] """ q, r = dmp_div(f, g, u, K) if dmp_zero_p(r, u): return q else: raise ExactQuotientFailed(f, g)
def dup_max_norm(f, K): """ Returns maximum norm of a polynomial in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_max_norm(-x**2 + 2*x - 3) 3 """ if not f: return K.zero else: return max(dup_abs(f, K))
[docs]def dmp_max_norm(f, u, K): """ Returns maximum norm of a polynomial in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x,y = ring("x,y", ZZ) >>> R.dmp_max_norm(2*x*y - x - 3) 3 """ if not u: return dup_max_norm(f, K) v = u - 1 return max([ dmp_max_norm(c, v, K) for c in f ])
def dup_l1_norm(f, K): """ Returns l1 norm of a polynomial in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_l1_norm(2*x**3 - 3*x**2 + 1) 6 """ if not f: return K.zero else: return sum(dup_abs(f, K))
[docs]def dmp_l1_norm(f, u, K): """ Returns l1 norm of a polynomial in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x,y = ring("x,y", ZZ) >>> R.dmp_l1_norm(2*x*y - x - 3) 6 """ if not u: return dup_l1_norm(f, K) v = u - 1 return sum([ dmp_l1_norm(c, v, K) for c in f ])
def dup_expand(polys, K): """ Multiply together several polynomials in ``K[x]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x = ring("x", ZZ) >>> R.dup_expand([x**2 - 1, x, 2]) 2*x**3 - 2*x """ if not polys: return [K.one] f = polys[0] for g in polys[1:]: f = dup_mul(f, g, K) return f
[docs]def dmp_expand(polys, u, K): """ Multiply together several polynomials in ``K[X]``. Examples ======== >>> from sympy.polys import ring, ZZ >>> R, x,y = ring("x,y", ZZ) >>> R.dmp_expand([x**2 + y**2, x + 1]) x**3 + x**2 + x*y**2 + y**2 """ if not polys: return dmp_one(u, K) f = polys[0] for g in polys[1:]: f = dmp_mul(f, g, u, K) return f