def from_FractionField(K1, a, K0):
"""
Convert a fraction field element to another fraction field.
Examples
========
>>> from sympy.polys.polyclasses import DMF
>>> from sympy.polys.domains import ZZ, QQ
>>> from sympy.abc import x
>>> f = DMF(([ZZ(1), ZZ(2)], [ZZ(1), ZZ(1)]), ZZ)
>>> QQx = QQ.frac_field(x)
>>> ZZx = ZZ.frac_field(x)
>>> QQx.from_FractionField(f, ZZx)
(x + 2)/(x + 1)
"""
if K1.gens == K0.gens:
if K1.dom == K0.dom:
return a
else:
return K1((a.numer().convert(K1.dom).rep,
a.denom().convert(K1.dom).rep))
elif set(K0.gens).issubset(K1.gens):
nmonoms, ncoeffs = _dict_reorder(a.numer().to_dict(), K0.gens, K1.gens)
dmonoms, dcoeffs = _dict_reorder(a.denom().to_dict(), K0.gens, K1.gens)
if K1.dom != K0.dom:
ncoeffs = [ K1.dom.convert(c, K0.dom) for c in ncoeffs ]
dcoeffs = [ K1.dom.convert(c, K0.dom) for c in dcoeffs ]
return K1((dict(zip(nmonoms, ncoeffs)), dict(zip(dmonoms, dcoeffs))))
def set_ring(self, new_ring):
if self.ring == new_ring:
return self
elif self.ring.symbols != new_ring.symbols:
terms = zip(*_dict_reorder(self, self.ring.symbols, new_ring.symbols))
return new_ring.from_terms(terms)
else:
return new_ring.from_dict(self)
def from_GlobalPolynomialRing(K1, a, K0):
"""Convert a `DMP` object to `dtype`. """
if K1.gens == K0.gens:
if K1.dom == K0.dom:
return K1(a.rep) # set the correct ring
else:
return K1(a.convert(K1.dom).rep)
else:
monoms, coeffs = _dict_reorder(a.to_dict(), K0.gens, K1.gens)
if K1.dom != K0.dom:
coeffs = [ K1.dom.convert(c, K0.dom) for c in coeffs ]
return K1(dict(zip(monoms, coeffs)))
def from_GlobalPolynomialRing(K1, a, K0):
"""Convert a `DMP` object to `dtype`. """
if K1.gens == K0.gens:
if K1.dom == K0.dom:
return K1(a.rep) # set the correct ring
else:
return K1(a.convert(K1.dom).rep)
else:
monoms, coeffs = _dict_reorder(a.to_dict(), K0.gens, K1.gens)
if K1.dom != K0.dom:
coeffs = [ K1.dom.convert(c, K0.dom) for c in coeffs ]
return K1(dict(zip(monoms, coeffs)))
def from_PolynomialRing(K1, a, K0):
"""Convert a ``PolyElement`` object to ``dtype``. """
if K1.gens == K0.symbols:
if K1.dom == K0.dom:
return K1(dict(a)) # set the correct ring
else:
convert_dom = lambda c: K1.dom.convert_from(c, K0.dom)
return K1({m: convert_dom(c) for m, c in a.items()})
else:
monoms, coeffs = _dict_reorder(a.to_dict(), K0.symbols, K1.gens)
if K1.dom != K0.dom:
coeffs = [ K1.dom.convert(c, K0.dom) for c in coeffs ]
return K1(dict(zip(monoms, coeffs)))
