def __init__(self, f, g, check=True):
if check:
if not morphism.is_SchemeMorphism(f):
raise TypeError, "f (=%s) must be a scheme morphism"%f
if not morphism.is_SchemeMorphism(g):
raise TypeError, "g (=%s) must be a scheme morphism"%g
if f.domain() != g.domain():
raise ValueError, "f (=%s) and g (=%s) must have the same domain"%(f,g)
self.__f = f
self.__g = g
def __init__(self, f, g, check=True):
if check:
if not morphism.is_SchemeMorphism(f):
raise TypeError, "f (=%s) must be a scheme morphism" % f
if not morphism.is_SchemeMorphism(g):
raise TypeError, "g (=%s) must be a scheme morphism" % g
if f.domain() != g.domain():
raise ValueError, "f (=%s) and g (=%s) must have the same domain" % (
f, g)
self.__f = f
self.__g = g
def __init__(self, v, parent=None, check=True, reduce=True):
"""
Construct a divisor on a curve.
INPUT:
- ``v`` -- a list of pairs ``(c, P)``, where ``c`` is an
integer and ``P`` is a point on a curve. The P's must all
lie on the same curve.
- To create the divisor 0 use ``[(0, P)]``, so as to give the curve.
EXAMPLES::
sage: E = EllipticCurve([0, 0, 1, -1, 0])
sage: P = E(0,0)
sage: from sage.schemes.generic.divisor import Divisor_curve
sage: from sage.schemes.generic.divisor_group import DivisorGroup
sage: Divisor_curve([(1,P)], parent=DivisorGroup(E))
(x, y)
"""
from sage.schemes.generic.divisor_group import DivisorGroup_generic, DivisorGroup_curve
if not isinstance(v, (list, tuple)):
v = [(1,v)]
if parent is None:
if len(v) > 0:
t = v[0]
if isinstance(t, tuple) and len(t) == 2:
try:
C = t[1].scheme()
except (TypeError, AttributeError):
raise TypeError, \
"Argument v (= %s) must consist of multiplicities and points on a scheme."
else:
try:
C = t.scheme()
except TypeError:
raise TypeError, \
"Argument v (= %s) must consist of multiplicities and points on a scheme."
parent = DivisorGroup(C)
else:
raise TypeError, \
"Argument v (= %s) must consist of multiplicities and points on a scheme."
else:
if not isinstance(parent, DivisorGroup_curve):
raise TypeError, "parent (of type %s) must be a DivisorGroup_curve"%type(parent)
C = parent.scheme()
if len(v) < 1:
check = False
know_points = False
if check:
w = []
points = []
know_points = True
for t in v:
if isinstance(t, tuple) and len(t) == 2:
n = ZZ(t[0])
I = t[1]
points.append((n,I))
else:
n = ZZ(1)
I = t
if is_SchemeMorphism(I):
I = CurvePointToIdeal(C,I)
else:
know_points = False
w.append((n,I))
v = w
Divisor_generic.__init__(
self, v, check=False, reduce=True, parent=parent)
if know_points:
self._points = points
def __init__(self, v, parent=None, check=True, reduce=True):
"""
Construct a divisor on a curve.
INPUT:
- ``v`` -- a list of pairs ``(c, P)``, where ``c`` is an
integer and ``P`` is a point on a curve. The P's must all
lie on the same curve.
- To create the divisor 0 use ``[(0, P)]``, so as to give the curve.
EXAMPLES::
sage: E = EllipticCurve([0, 0, 1, -1, 0])
sage: P = E(0,0)
sage: from sage.schemes.generic.divisor import Divisor_curve
sage: from sage.schemes.generic.divisor_group import DivisorGroup
sage: Divisor_curve([(1,P)], parent=DivisorGroup(E))
(x, y)
"""
from sage.schemes.generic.divisor_group import DivisorGroup_generic, DivisorGroup_curve
if not isinstance(v, (list, tuple)):
v = [(1, v)]
if parent is None:
if len(v) > 0:
t = v[0]
if isinstance(t, tuple) and len(t) == 2:
try:
C = t[1].scheme()
except (TypeError, AttributeError):
raise TypeError(
"Argument v (= %s) must consist of multiplicities and points on a scheme."
)
else:
try:
C = t.scheme()
except TypeError:
raise TypeError(
"Argument v (= %s) must consist of multiplicities and points on a scheme."
)
parent = DivisorGroup(C)
else:
raise TypeError(
"Argument v (= %s) must consist of multiplicities and points on a scheme."
)
else:
if not isinstance(parent, DivisorGroup_curve):
raise TypeError(
"parent (of type %s) must be a DivisorGroup_curve" %
type(parent))
C = parent.scheme()
if len(v) < 1:
check = False
know_points = False
if check:
w = []
points = []
know_points = True
for t in v:
if isinstance(t, tuple) and len(t) == 2:
n = ZZ(t[0])
I = t[1]
points.append((n, I))
else:
n = ZZ(1)
I = t
if is_SchemeMorphism(I):
I = CurvePointToIdeal(C, I)
else:
know_points = False
w.append((n, I))
v = w
Divisor_generic.__init__(self,
v,
check=False,
reduce=True,
parent=parent)
if know_points:
self._points = points
