Ejemplo n.º 1
0
def make_extra_data(label, number, ainvs, gens):
    """Given a curve label (and number, as some data is only stored wih
    curve number 1 in each class) and its ainvs and gens, returns a
    dict with which to update the entry.

    Extra items computed here:
    'equation': latex string of curve's equation
    'signD': sign of discriminant
    'local_data': list of dicts, one item for each bad prime
    'min_quad_twist': dict holding curve's min quadratic twist and the twisting discriminant
    'heights': list of heights of gens

    and for curve #1 in a class only:

    'aplist': list of a_p for p<100
    'anlist': list of a_n for n<=20

    """
    E = EllipticCurve(parse_ainvs(ainvs))
    data = {}
    # convert from a list of strings to a single string, e.g. from ['0','0','0','1','1'] to '[0,0,0,1,1]'
    data['equation'] = web_latex(E)
    data['signD'] = int(E.discriminant().sign())
    data['local_data'] = [{
        'p':
        int(ld.prime().gen()),
        'ord_cond':
        int(ld.conductor_valuation()),
        'ord_disc':
        int(ld.discriminant_valuation()),
        'ord_den_j':
        int(max(0, -(E.j_invariant().valuation(ld.prime().gen())))),
        'red':
        int(ld.bad_reduction_type()),
        'rootno':
        int(E.root_number(ld.prime().gen())),
        'kod':
        web_latex(ld.kodaira_symbol()).replace('$', ''),
        'cp':
        int(ld.tamagawa_number())
    } for ld in E.local_data()]
    Etw, Dtw = E.minimal_quadratic_twist()
    if Etw.conductor() == E.conductor():
        data['min_quad_twist'] = {'label': label, 'disc': int(1)}
    else:
        minq_ainvs = ''.join(['['] + [str(c) for c in Etw.ainvs()] + [']'])
        r = curves.find_one({
            'jinv': str(E.j_invariant()),
            'ainvs': minq_ainvs
        })
        minq_label = "" if r is None else r['label']
        data['min_quad_twist'] = {'label': minq_label, 'disc': int(Dtw)}
    from lmfdb.elliptic_curves.web_ec import parse_points
    gens = [E(g) for g in parse_points(gens)]
    data['heights'] = [float(P.height()) for P in gens]
    if number == 1:
        data['aplist'] = E.aplist(100, python_ints=True)
        data['anlist'] = E.anlist(20, python_ints=True)
    return data
Ejemplo n.º 2
0
def make_extra_data(label, number, ainvs, gens):
    """
    C is a database elliptic curve entry.  Returns a dict with which to update the entry.

    Data fields needed in C already: 'ainvs', 'lmfdb_label', 'gens', 'number'
    """
    E = EllipticCurve([int(a) for a in ainvs])
    data = {}
    # convert from a list of strings to a single string, e.g. from ['0','0','0','1','1'] to '[0,0,0,1,1]'
    data['xainvs'] = ''.join(['[', ','.join(ainvs), ']'])
    data['equation'] = web_latex(E)
    data['signD'] = int(E.discriminant().sign())
    data['local_data'] = [{
        'p':
        int(ld.prime().gen()),
        'ord_cond':
        int(ld.conductor_valuation()),
        'ord_disc':
        int(ld.discriminant_valuation()),
        'ord_den_j':
        int(max(0, -(E.j_invariant().valuation(ld.prime().gen())))),
        'red':
        int(ld.bad_reduction_type()),
        'rootno':
        int(E.root_number(ld.prime().gen())),
        'kod':
        web_latex(ld.kodaira_symbol()).replace('$', ''),
        'cp':
        int(ld.tamagawa_number())
    } for ld in E.local_data()]
    Etw, Dtw = E.minimal_quadratic_twist()
    if Etw.conductor() == E.conductor():
        data['min_quad_twist'] = {'label': label, 'disc': int(1)}
    else:
        # Later this should be changed to look for xainvs but now all curves have ainvs
        minq_ainvs = [str(c) for c in Etw.ainvs()]
        r = curves.find_one({
            'jinv': str(E.j_invariant()),
            'ainvs': minq_ainvs
        })
        minq_label = "" if r is None else r['label']
        data['min_quad_twist'] = {'label': minq_label, 'disc': int(Dtw)}
    from lmfdb.elliptic_curves.web_ec import parse_points
    gens = [E(g) for g in parse_points(gens)]
    data['heights'] = [float(P.height()) for P in gens]
    if number == 1:
        data['aplist'] = E.aplist(100, python_ints=True)
        data['anlist'] = E.anlist(20, python_ints=True)
    return data
Ejemplo n.º 3
0
def make_extra_data(label,number,ainvs,gens):
    """Given a curve label (and number, as some data is only stored wih
    curve number 1 in each class) and its ainvs and gens, returns a
    dict with which to update the entry.

    Extra items computed here:
    'equation': latex string of curve's equation
    'signD': sign of discriminant
    'local_data': list of dicts, one item for each bad prime
    'min_quad_twist': dict holding curve's min quadratic twist and the twisting discriminant
    'heights': list of heights of gens

    and for curve #1 in a class only:

    'aplist': list of a_p for p<100
    'anlist': list of a_n for n<=20

    """
    E = EllipticCurve(parse_ainvs(ainvs))
    data = {}
    # convert from a list of strings to a single string, e.g. from ['0','0','0','1','1'] to '[0,0,0,1,1]'
    data['equation'] = web_latex(E)
    data['signD'] = int(E.discriminant().sign())
    data['local_data'] = [{'p': int(ld.prime().gen()),
                           'ord_cond':int(ld.conductor_valuation()),
                           'ord_disc':int(ld.discriminant_valuation()),
                           'ord_den_j':int(max(0,-(E.j_invariant().valuation(ld.prime().gen())))),
                           'red':int(ld.bad_reduction_type()),
                           'rootno':int(E.root_number(ld.prime().gen())),
                           'kod':web_latex(ld.kodaira_symbol()).replace('$',''),
                           'cp':int(ld.tamagawa_number())}
                          for ld in E.local_data()]
    Etw, Dtw = E.minimal_quadratic_twist()
    if Etw.conductor()==E.conductor():
        data['min_quad_twist'] = {'label':label, 'disc':int(1)}
    else:
        minq_ainvs = ''.join(['['] + [str(c) for c in Etw.ainvs()] + [']'])
        r = curves.find_one({'jinv':str(E.j_invariant()), 'ainvs':minq_ainvs})
        minq_label = "" if r is None else r['label']
        data['min_quad_twist'] = {'label':minq_label, 'disc':int(Dtw)}
    from lmfdb.elliptic_curves.web_ec import parse_points
    gens = [E(g) for g in parse_points(gens)]
    data['heights'] = [float(P.height()) for P in gens]
    if number==1:
        data['aplist'] = E.aplist(100,python_ints=True)
        data['anlist'] = E.anlist(20,python_ints=True)
    return data
Ejemplo n.º 4
0
def make_extra_data(label,number,ainvs,gens):
    """
    C is a database elliptic curve entry.  Returns a dict with which to update the entry.

    Data fields needed in C already: 'ainvs', 'lmfdb_label', 'gens', 'number'
    """
    E = EllipticCurve([int(a) for a in ainvs])
    data = {}
    # convert from a list of strings to a single string, e.g. from ['0','0','0','1','1'] to '[0,0,0,1,1]'
    data['xainvs'] = ''.join(['[',','.join(ainvs),']'])
    data['equation'] = web_latex(E)
    data['signD'] = int(E.discriminant().sign())
    data['local_data'] = [{'p': int(ld.prime().gen()),
                           'ord_cond':int(ld.conductor_valuation()),
                           'ord_disc':int(ld.discriminant_valuation()),
                           'ord_den_j':int(max(0,-(E.j_invariant().valuation(ld.prime().gen())))),
                           'red':int(ld.bad_reduction_type()),
                           'rootno':int(E.root_number(ld.prime().gen())),
                           'kod':web_latex(ld.kodaira_symbol()).replace('$',''),
                           'cp':int(ld.tamagawa_number())}
                          for ld in E.local_data()]
    Etw, Dtw = E.minimal_quadratic_twist()
    if Etw.conductor()==E.conductor():
        data['min_quad_twist'] = {'label':label, 'disc':int(1)}
    else:
        # Later this should be changed to look for xainvs but now all curves have ainvs
        minq_ainvs = [str(c) for c in Etw.ainvs()]
        r = curves.find_one({'jinv':str(E.j_invariant()), 'ainvs':minq_ainvs})
        minq_label = "" if r is None else r['label']
        data['min_quad_twist'] = {'label':minq_label, 'disc':int(Dtw)}
    from lmfdb.elliptic_curves.web_ec import parse_points
    gens = [E(g) for g in parse_points(gens)]
    data['heights'] = [float(P.height()) for P in gens]
    if number==1:
        data['aplist'] = E.aplist(100,python_ints=True)
        data['anlist'] = E.anlist(20,python_ints=True)
    return data
Ejemplo n.º 5
0
class WebEC(object):
    """
    Class for an elliptic curve over Q
    """
    def __init__(self, dbdata):
        """
        Arguments:

            - dbdata: the data from the database
        """
        logger.debug("Constructing an instance of WebEC")
        self.__dict__.update(dbdata)
        # Next lines because the hyphens make trouble
        self.xintcoords = split_list(
            dbdata['x-coordinates_of_integral_points'])
        self.non_surjective_primes = dbdata['non-surjective_primes']
        # Next lines because the python identifiers cannot start with 2
        self.twoadic_index = dbdata['2adic_index']
        self.twoadic_log_level = dbdata['2adic_log_level']
        self.twoadic_gens = dbdata['2adic_gens']
        self.twoadic_label = dbdata['2adic_label']
        # All other fields are handled here
        self.make_curve()

    @staticmethod
    def by_label(label):
        """
        Searches for a specific elliptic curve in the curves
        collection by its label, which can be either in LMFDB or
        Cremona format.
        """
        try:
            N, iso, number = split_lmfdb_label(label)
            data = db_ec().find_one({"lmfdb_label": label})
        except AttributeError:
            try:
                N, iso, number = split_cremona_label(label)
                data = db_ec().find_one({"label": label})
            except AttributeError:
                return "Invalid label"  # caller must catch this and raise an error

        if data:
            return WebEC(data)
        return "Curve not found"  # caller must catch this and raise an error

    def make_curve(self):
        # To start with the data fields of self are just those from
        # the database.  We need to reformat these.

        # Old version: required constructing the actual elliptic curve
        # E, and computing some further data about it.

        # New version (May 2016): extra data fields now in the
        # database so we do not have to construct the curve or do any
        # computation with it on the fly.  As a failsafe the old way
        # is still included.

        data = self.data = {}
        try:
            data['ainvs'] = [int(c) for c in self.xainvs[1:-1].split(',')]
        except AttributeError:
            data['ainvs'] = [int(ai) for ai in self.ainvs]
        data['conductor'] = N = ZZ(self.conductor)
        data['j_invariant'] = QQ(str(self.jinv))
        data['j_inv_factor'] = latex(0)
        if data['j_invariant']:  # don't factor 0
            data['j_inv_factor'] = latex(data['j_invariant'].factor())
        data['j_inv_str'] = unicode(str(data['j_invariant']))
        data['j_inv_latex'] = web_latex(data['j_invariant'])
        mw = self.mw = {}
        mw['rank'] = self.rank
        mw['int_points'] = ''
        if self.xintcoords:
            a1, a2, a3, a4, a6 = [ZZ(a) for a in data['ainvs']]

            def lift_x(x):
                f = ((x + a2) * x + a4) * x + a6
                b = (a1 * x + a3)
                d = (b * b + 4 * f).sqrt()
                return (x, (-b + d) / 2)

            mw['int_points'] = ', '.join(
                web_latex(lift_x(x)) for x in self.xintcoords)

        mw['generators'] = ''
        mw['heights'] = []
        if self.gens:
            mw['generators'] = [
                web_latex(tuple(P)) for P in parse_points(self.gens)
            ]

        mw['tor_order'] = self.torsion
        tor_struct = [int(c) for c in self.torsion_structure]
        if mw['tor_order'] == 1:
            mw['tor_struct'] = '\mathrm{Trivial}'
            mw['tor_gens'] = ''
        else:
            mw['tor_struct'] = ' \\times '.join(
                ['\Z/{%s}\Z' % n for n in tor_struct])
            mw['tor_gens'] = ', '.join(
                web_latex(tuple(P))
                for P in parse_points(self.torsion_generators))

        # try to get all the data we need from the database entry (now in self)
        try:
            data['equation'] = self.equation
            local_data = self.local_data
            D = self.signD * prod(
                [ld['p']**ld['ord_disc'] for ld in local_data])
            data['disc'] = D
            Nfac = Factorization([(ZZ(ld['p']), ld['ord_cond'])
                                  for ld in local_data])
            Dfac = Factorization([(ZZ(ld['p']), ld['ord_disc'])
                                  for ld in local_data],
                                 unit=ZZ(self.signD))

            data['minq_D'] = minqD = self.min_quad_twist['disc']
            minq_label = self.min_quad_twist['label']
            data['minq_label'] = db_ec().find_one(
                {'label': minq_label}, ['lmfdb_label'])['lmfdb_label']
            data['minq_info'] = '(itself)' if minqD == 1 else '(by %s)' % minqD
            try:
                data['degree'] = self.degree
            except AttributeError:
                data['degree'] = 0  # invalid, but will be displayed nicely
            mw['heights'] = self.heights
            if self.number == 1:
                data['an'] = self.anlist
                data['ap'] = self.aplist
            else:
                r = db_ec().find_one({
                    'lmfdb_iso': self.lmfdb_iso,
                    'number': 1
                }, ['anlist', 'aplist'])
                data['an'] = r['anlist']
                data['ap'] = r['aplist']

        # otherwise fall back to computing it from the curve
        except AttributeError:
            print("Falling back to constructing E")
            self.E = EllipticCurve(data['ainvs'])
            data['equation'] = web_latex(self.E)
            data['disc'] = D = self.E.discriminant()
            Nfac = N.factor()
            Dfac = D.factor()
            bad_primes = [p for p, e in Nfac]
            try:
                data['degree'] = self.degree
            except AttributeError:
                try:
                    data['degree'] = self.E.modular_degree()
                except RuntimeError:
                    data['degree'] = 0  # invalid, but will be displayed nicely
            minq, minqD = self.E.minimal_quadratic_twist()
            data['minq_D'] = minqD
            if minqD == 1:
                data['minq_label'] = self.lmfdb_label
                data['minq_info'] = '(itself)'
            else:
                # This relies on the minimal twist being in the
                # database, which is true when the database only
                # contains the Cremona database.  It would be a good
                # idea if, when the database is extended, we ensured
                # that for any curve included, all twists of smaller
                # conductor are also included.
                minq_ainvs = [str(c) for c in minq.ainvs()]
                data['minq_label'] = db_ec().find_one(
                    {
                        'jinv': str(self.E.j_invariant()),
                        'ainvs': minq_ainvs
                    }, ['lmfdb_label'])['lmfdb_label']
                data['minq_info'] = '(by %s)' % minqD

            if self.gens:
                self.generators = [self.E(g) for g in parse_points(self.gens)]
                mw['heights'] = [P.height() for P in self.generators]

            data['an'] = self.E.anlist(20, python_ints=True)
            data['ap'] = self.E.aplist(100, python_ints=True)
            self.local_data = local_data = []
            for p in bad_primes:
                ld = self.E.local_data(p, algorithm="generic")
                local_data_p = {}
                local_data_p['p'] = p
                local_data_p['cp'] = ld.tamagawa_number()
                local_data_p['kod'] = web_latex(ld.kodaira_symbol()).replace(
                    '$', '')
                local_data_p['red'] = ld.bad_reduction_type()
                rootno = -ld.bad_reduction_type()
                if rootno == 0:
                    rootno = self.E.root_number(p)
                local_data_p['rootno'] = rootno
                local_data_p['ord_cond'] = ld.conductor_valuation()
                local_data_p['ord_disc'] = ld.discriminant_valuation()
                local_data_p['ord_den_j'] = max(
                    0, -self.E.j_invariant().valuation(p))
                local_data.append(local_data_p)

        # If we got the data from the database, the root numbers may
        # not have been stored there, so we have to compute them.  If
        # there are additive primes this means constructing the curve.
        for ld in self.local_data:
            if not 'rootno' in ld:
                rootno = -ld['red']
                if rootno == 0:
                    try:
                        E = self.E
                    except AttributeError:
                        self.E = E = EllipticCurve(data['ainvs'])
                    rootno = E.root_number(ld['p'])
                ld['rootno'] = rootno

        minq_N, minq_iso, minq_number = split_lmfdb_label(data['minq_label'])

        data['disc_factor'] = latex(Dfac)
        data['cond_factor'] = latex(Nfac)
        data['disc_latex'] = web_latex(D)
        data['cond_latex'] = web_latex(N)

        data['CMD'] = self.cm
        data['CM'] = "no"
        data['EndE'] = "\(\Z\)"
        if self.cm:
            data['CM'] = "yes (\(D=%s\))" % data['CMD']
            if data['CMD'] % 4 == 0:
                d4 = ZZ(data['CMD']) // 4
                data['EndE'] = "\(\Z[\sqrt{%s}]\)" % d4
            else:
                data['EndE'] = "\(\Z[(1+\sqrt{%s})/2]\)" % data['CMD']
            data['ST'] = st_link_by_name(1, 2, 'N(U(1))')
        else:
            data['ST'] = st_link_by_name(1, 2, 'SU(2)')

        data['p_adic_primes'] = [
            p for i, p in enumerate(prime_range(5, 100))
            if (N * data['ap'][i]) % p != 0
        ]

        try:
            data['galois_images'] = [
                trim_galois_image_code(s) for s in self.galois_images
            ]
            data['non_surjective_primes'] = self.non_surjective_primes
        except AttributeError:
            #print "No Galois image data"
            data['galois_images'] = []
            data['non_surjective_primes'] = []

        data['galois_data'] = [{
            'p': p,
            'image': im
        } for p, im in zip(data['non_surjective_primes'],
                           data['galois_images'])]

        cond, iso, num = split_lmfdb_label(self.lmfdb_label)
        self.class_url = url_for(".by_double_iso_label",
                                 conductor=N,
                                 iso_label=iso)
        self.ncurves = db_ec().count({'lmfdb_iso': self.lmfdb_iso})
        isodegs = [str(d) for d in self.isogeny_degrees if d > 1]
        if len(isodegs) < 3:
            data['isogeny_degrees'] = " and ".join(isodegs)
        else:
            data['isogeny_degrees'] = " and ".join(
                [", ".join(isodegs[:-1]), isodegs[-1]])

        if self.twoadic_gens:
            from sage.matrix.all import Matrix
            data['twoadic_gen_matrices'] = ','.join(
                [latex(Matrix(2, 2, M)) for M in self.twoadic_gens])
            data[
                'twoadic_rouse_url'] = ROUSE_URL_PREFIX + self.twoadic_label + ".html"

        # Leading term of L-function & BSD data
        bsd = self.bsd = {}
        r = self.rank
        if r >= 2:
            bsd['lder_name'] = "L^{(%s)}(E,1)/%s!" % (r, r)
        elif r:
            bsd['lder_name'] = "L'(E,1)"
        else:
            bsd['lder_name'] = "L(E,1)"

        bsd['reg'] = self.regulator
        bsd['omega'] = self.real_period
        bsd['sha'] = int(0.1 + self.sha_an)
        bsd['lder'] = self.special_value

        # Optimality (the optimal curve in the class is the curve
        # whose Cremona label ends in '1' except for '990h' which was
        # labelled wrongly long ago)

        if self.iso == '990h':
            data['Gamma0optimal'] = bool(self.number == 3)
        else:
            data['Gamma0optimal'] = bool(self.number == 1)

        data['p_adic_data_exists'] = False
        if data['Gamma0optimal']:
            data['p_adic_data_exists'] = (padic_db().find({
                'lmfdb_iso':
                self.lmfdb_iso
            }).count()) > 0

        tamagawa_numbers = [ZZ(ld['cp']) for ld in local_data]
        cp_fac = [cp.factor() for cp in tamagawa_numbers]
        cp_fac = [
            latex(cp) if len(cp) < 2 else '(' + latex(cp) + ')'
            for cp in cp_fac
        ]
        bsd['tamagawa_factors'] = r'\cdot'.join(cp_fac)
        bsd['tamagawa_product'] = prod(tamagawa_numbers)

        data['newform'] = web_latex(
            PowerSeriesRing(QQ, 'q')(data['an'], 20, check=True))
        data['newform_label'] = self.newform_label = newform_label(
            cond, 2, 1, iso)
        self.newform_link = url_for("emf.render_elliptic_modular_forms",
                                    level=cond,
                                    weight=2,
                                    character=1,
                                    label=iso)
        self.newform_exists_in_db = is_newform_in_db(self.newform_label)
        self._code = None

        self.class_url = url_for(".by_double_iso_label",
                                 conductor=N,
                                 iso_label=iso)
        self.friends = [('Isogeny class ' + self.lmfdb_iso, self.class_url),
                        ('Minimal quadratic twist %s %s' %
                         (data['minq_info'], data['minq_label']),
                         url_for(".by_triple_label",
                                 conductor=minq_N,
                                 iso_label=minq_iso,
                                 number=minq_number)),
                        ('All twists ',
                         url_for(".rational_elliptic_curves", jinv=self.jinv)),
                        ('L-function',
                         url_for("l_functions.l_function_ec_page",
                                 label=self.lmfdb_label))]
        if not self.cm:
            if N <= 300:
                self.friends += [('Symmetric square L-function',
                                  url_for("l_functions.l_function_ec_sym_page",
                                          power='2',
                                          label=self.lmfdb_iso))]
            if N <= 50:
                self.friends += [('Symmetric cube L-function',
                                  url_for("l_functions.l_function_ec_sym_page",
                                          power='3',
                                          label=self.lmfdb_iso))]
        if self.newform_exists_in_db:
            self.friends += [('Modular form ' + self.newform_label,
                              self.newform_link)]

        self.downloads = [('Download coefficients of q-expansion',
                           url_for(".download_EC_qexp",
                                   label=self.lmfdb_label,
                                   limit=1000)),
                          ('Download all stored data',
                           url_for(".download_EC_all",
                                   label=self.lmfdb_label)),
                          ('Download Magma code',
                           url_for(".ec_code_download",
                                   conductor=cond,
                                   iso=iso,
                                   number=num,
                                   label=self.lmfdb_label,
                                   download_type='magma')),
                          ('Download Sage code',
                           url_for(".ec_code_download",
                                   conductor=cond,
                                   iso=iso,
                                   number=num,
                                   label=self.lmfdb_label,
                                   download_type='sage')),
                          ('Download GP code',
                           url_for(".ec_code_download",
                                   conductor=cond,
                                   iso=iso,
                                   number=num,
                                   label=self.lmfdb_label,
                                   download_type='gp'))]

        try:
            self.plot = encode_plot(self.E.plot())
        except AttributeError:
            self.plot = encode_plot(EllipticCurve(data['ainvs']).plot())

        self.plot_link = '<img src="%s" width="200" height="150"/>' % self.plot
        self.properties = [('Label', self.lmfdb_label), (None, self.plot_link),
                           ('Conductor', '\(%s\)' % data['conductor']),
                           ('Discriminant', '\(%s\)' % data['disc']),
                           ('j-invariant', '%s' % data['j_inv_latex']),
                           ('CM', '%s' % data['CM']),
                           ('Rank', '\(%s\)' % mw['rank']),
                           ('Torsion Structure', '\(%s\)' % mw['tor_struct'])]

        self.title = "Elliptic Curve %s (Cremona label %s)" % (
            self.lmfdb_label, self.label)

        self.bread = [('Elliptic Curves', url_for("ecnf.index")),
                      ('$\Q$', url_for(".rational_elliptic_curves")),
                      ('%s' % N, url_for(".by_conductor", conductor=N)),
                      ('%s' % iso,
                       url_for(".by_double_iso_label",
                               conductor=N,
                               iso_label=iso)), ('%s' % num, ' ')]

    def code(self):
        if self._code == None:
            self.make_code_snippets()
        return self._code

    def make_code_snippets(self):
        # read in code.yaml from current directory:

        _curdir = os.path.dirname(os.path.abspath(__file__))
        self._code = yaml.load(open(os.path.join(_curdir, "code.yaml")))

        # Fill in placeholders for this specific curve:

        for lang in ['sage', 'pari', 'magma']:
            self._code['curve'][lang] = self._code['curve'][lang] % (
                self.data['ainvs'], self.label)
        return
        for k in self._code:
            if k != 'prompt':
                for lang in self._code[k]:
                    self._code[k][lang] = self._code[k][lang].split("\n")
                    # remove final empty line
                    if len(self._code[k][lang][-1]) == 0:
                        self._code[k][lang] = self._code[k][lang][:-1]
Ejemplo n.º 6
0
class WebEC(object):
    """
    Class for an elliptic curve over Q
    """
    def __init__(self, dbdata):
        """
        Arguments:

            - dbdata: the data from the database
        """
        logger.debug("Constructing an instance of ECisog_class")
        self.__dict__.update(dbdata)
        # Next lines because the hyphens make trouble
        self.xintcoords = split_list(dbdata['x-coordinates_of_integral_points'])
        self.non_surjective_primes = dbdata['non-surjective_primes']
        # Next lines because the python identifiers cannot start with 2
        self.twoadic_index = dbdata['2adic_index']
        self.twoadic_log_level = dbdata['2adic_log_level']
        self.twoadic_gens = dbdata['2adic_gens']
        self.twoadic_label = dbdata['2adic_label']
        # All other fields are handled here
        self.make_curve()

    @staticmethod
    def by_label(label):
        """
        Searches for a specific elliptic curve in the curves
        collection by its label, which can be either in LMFDB or
        Cremona format.
        """
        try:
            N, iso, number = split_lmfdb_label(label)
            data = db_ec().find_one({"lmfdb_label" : label})
        except AttributeError:
            try:
                N, iso, number = split_cremona_label(label)
                data = db_ec().find_one({"label" : label})
            except AttributeError:
                return "Invalid label" # caller must catch this and raise an error

        if data:
            return WebEC(data)
        return "Curve not found" # caller must catch this and raise an error

    def make_curve(self):
        # To start with the data fields of self are just those from
        # the database.  We need to reformat these.

        # Old version: required constructing the actual elliptic curve
        # E, and computing some further data about it.

        # New version (May 2016): extra data fields now in the
        # database so we do not have to construct the curve or do any
        # computation with it on the fly.  As a failsafe the old way
        # is still included.

        data = self.data = {}
        try:
            data['ainvs'] = [int(c) for c in self.xainvs[1:-1].split(',')]
        except AttributeError:
            data['ainvs'] = [int(ai) for ai in self.ainvs]
        data['conductor'] = N = ZZ(self.conductor)
        data['j_invariant'] = QQ(str(self.jinv))
        data['j_inv_factor'] = latex(0)
        if data['j_invariant']: # don't factor 0
            data['j_inv_factor'] = latex(data['j_invariant'].factor())
        data['j_inv_str'] = unicode(str(data['j_invariant']))
        data['j_inv_latex'] = web_latex(data['j_invariant'])
        mw = self.mw = {}
        mw['rank'] = self.rank
        mw['int_points'] = ''
        if self.xintcoords:
            a1, a2, a3, a4, a6 = [ZZ(a) for a in data['ainvs']]
            def lift_x(x):
                f = ((x + a2) * x + a4) * x + a6
                b = (a1*x + a3)
                d = (b*b + 4*f).sqrt()
                return (x, (-b+d)/2)
            mw['int_points'] = ', '.join(web_latex(lift_x(x)) for x in self.xintcoords)

        mw['generators'] = ''
        mw['heights'] = []
        if self.gens:
            mw['generators'] = [web_latex(tuple(P)) for P in parse_points(self.gens)]

        mw['tor_order'] = self.torsion
        tor_struct = [int(c) for c in self.torsion_structure]
        if mw['tor_order'] == 1:
            mw['tor_struct'] = '\mathrm{Trivial}'
            mw['tor_gens'] = ''
        else:
            mw['tor_struct'] = ' \\times '.join(['\Z/{%s}\Z' % n for n in tor_struct])
            mw['tor_gens'] = ', '.join(web_latex(tuple(P)) for P in parse_points(self.torsion_generators))

        # try to get all the data we need from the database entry (now in self)
        try:
            data['equation'] = self.equation
            local_data = self.local_data
            badprimes = [ZZ(ld['p']) for ld in local_data]
            D = self.signD * prod([ld['p']**ld['ord_disc'] for ld in local_data])
            data['disc'] = D
            Nfac = Factorization([(ZZ(ld['p']),ld['ord_cond']) for ld in local_data])
            Dfac = Factorization([(ZZ(ld['p']),ld['ord_disc']) for ld in local_data], unit=ZZ(self.signD))

            data['minq_D'] = minqD = self.min_quad_twist['disc']
            minq_label = self.min_quad_twist['label']
            data['minq_label'] = db_ec().find_one({'label':minq_label}, ['lmfdb_label'])['lmfdb_label']
            data['minq_info'] = '(itself)' if minqD==1 else '(by %s)' % minqD
            try:
                data['degree'] = self.degree
            except AttributeError:
                data['degree']  =0 # invalid, but will be displayed nicely
            mw['heights'] = self.heights
            if self.number == 1:
                data['an'] = self.anlist
                data['ap'] = self.aplist
            else:
                r = db_ec().find_one({'lmfdb_iso':self.lmfdb_iso, 'number':1}, ['anlist','aplist'])
                data['an'] = r['anlist']
                data['ap'] = r['aplist']

        # otherwise fall back to computing it from the curve
        except AttributeError:
            print("Falling back to constructing E")
            self.E = EllipticCurve(data['ainvs'])
            data['equation'] = web_latex(self.E)
            data['disc'] = D = self.E.discriminant()
            Nfac = N.factor()
            Dfac = D.factor()
            bad_primes = [p for p,e in Nfac]
            try:
                data['degree'] = self.degree
            except AttributeError:
                try:
                    data['degree'] = self.E.modular_degree()
                except RuntimeError:
                    data['degree'] = 0  # invalid, but will be displayed nicely
            minq, minqD = self.E.minimal_quadratic_twist()
            data['minq_D'] = minqD
            if minqD == 1:
                data['minq_label'] = self.lmfdb_label
                data['minq_info'] = '(itself)'
            else:
                # This relies on the minimal twist being in the
                # database, which is true when the database only
                # contains the Cremona database.  It would be a good
                # idea if, when the database is extended, we ensured
                # that for any curve included, all twists of smaller
                # conductor are also included.
                minq_ainvs = [str(c) for c in minq.ainvs()]
                data['minq_label'] = db_ec().find_one({'jinv':str(self.E.j_invariant()),
                                                       'ainvs': minq_ainvs},['lmfdb_label'])['lmfdb_label']
                data['minq_info'] = '(by %s)' % minqD

            if self.gens:
                self.generators = [self.E(g) for g in parse_points(self.gens)]
                mw['heights'] = [P.height() for P in self.generators]

            data['an'] = self.E.anlist(20,python_ints=True)
            data['ap'] = self.E.aplist(100,python_ints=True)
            self.local_data = local_data = []
            for p in bad_primes:
                ld = self.E.local_data(p, algorithm="generic")
                local_data_p = {}
                local_data_p['p'] = p
                local_data_p['cp'] = ld.tamagawa_number()
                local_data_p['kod'] = web_latex(ld.kodaira_symbol()).replace('$', '')
                local_data_p['red'] = ld.bad_reduction_type()
                local_data_p['ord_cond'] = ld.conductor_valuation()
                local_data_p['ord_disc'] = ld.discriminant_valuation()
                local_data_p['ord_den_j'] = max(0,-self.E.j_invariant().valuation(p))
                local_data.append(local_data_p)

        jfac = Factorization([(ZZ(ld['p']),ld['ord_den_j']) for ld in local_data])

        minq_N, minq_iso, minq_number = split_lmfdb_label(data['minq_label'])

        data['disc_factor'] = latex(Dfac)
        data['cond_factor'] =latex(Nfac)
        data['disc_latex'] = web_latex(D)
        data['cond_latex'] = web_latex(N)

        data['CMD'] = self.cm
        data['CM'] = "no"
        data['EndE'] = "\(\Z\)"
        if self.cm:
            data['CM'] = "yes (\(D=%s\))" % data['CMD']
            if data['CMD']%4==0:
                d4 = ZZ(data['CMD'])//4
                data['EndE'] = "\(\Z[\sqrt{%s}]\)" % d4
            else:
                data['EndE'] = "\(\Z[(1+\sqrt{%s})/2]\)" % data['CMD']
            data['ST'] = '<a href="%s">$%s$</a>' % (url_for('st.by_label', label='1.2.N(U(1))'),'N(\\mathrm{U}(1))')
        else:
            data['ST'] = '<a href="%s">$%s$</a>' % (url_for('st.by_label', label='1.2.SU(2)'),'\\mathrm{SU}(2)')

        data['p_adic_primes'] = [p for i,p in enumerate(sage.all.prime_range(5, 100))
                                 if (N*data['ap'][i]) %p !=0]

        try:
            data['galois_images'] = [trim_galois_image_code(s) for s in self.galois_images]
            data['non_surjective_primes'] = self.non_surjective_primes
        except AttributeError:
            #print "No Galois image data"
            data['galois_images'] = []
            data['non_surjective_primes'] = []

        data['galois_data'] = [{'p': p,'image': im }
                               for p,im in zip(data['non_surjective_primes'],
                                               data['galois_images'])]

        if self.twoadic_gens:
            from sage.matrix.all import Matrix
            data['twoadic_gen_matrices'] = ','.join([latex(Matrix(2,2,M)) for M in self.twoadic_gens])
            data['twoadic_rouse_url'] = ROUSE_URL_PREFIX + self.twoadic_label + ".html"

        # Leading term of L-function & BSD data
        bsd = self.bsd = {}
        r = self.rank
        if r >= 2:
            bsd['lder_name'] = "L^{(%s)}(E,1)/%s!" % (r,r)
        elif r:
            bsd['lder_name'] = "L'(E,1)"
        else:
            bsd['lder_name'] = "L(E,1)"

        bsd['reg'] = self.regulator
        bsd['omega'] = self.real_period
        bsd['sha'] = int(0.1+self.sha_an)
        bsd['lder'] = self.special_value

        # Optimality (the optimal curve in the class is the curve
        # whose Cremona label ends in '1' except for '990h' which was
        # labelled wrongly long ago)

        if self.iso == '990h':
            data['Gamma0optimal'] = bool(self.number == 3)
        else:
            data['Gamma0optimal'] = bool(self.number == 1)


        data['p_adic_data_exists'] = False
        if data['Gamma0optimal']:
            data['p_adic_data_exists'] = (padic_db().find({'lmfdb_iso': self.lmfdb_iso}).count()) > 0

        tamagawa_numbers = [ZZ(ld['cp']) for ld in local_data]
        cp_fac = [cp.factor() for cp in tamagawa_numbers]
        cp_fac = [latex(cp) if len(cp)<2 else '('+latex(cp)+')' for cp in cp_fac]
        bsd['tamagawa_factors'] = r'\cdot'.join(cp_fac)
        bsd['tamagawa_product'] = sage.misc.all.prod(tamagawa_numbers)

        cond, iso, num = split_lmfdb_label(self.lmfdb_label)
        data['newform'] =  web_latex(PowerSeriesRing(QQ, 'q')(data['an'], 20, check=True))
        data['newform_label'] = self.newform_label = newform_label(cond,2,1,iso)
        self.newform_link = url_for("emf.render_elliptic_modular_forms", level=cond, weight=2, character=1, label=iso)
        self.newform_exists_in_db = is_newform_in_db(self.newform_label)
        self._code = None

        self.friends = [
            ('Isogeny class ' + self.lmfdb_iso, url_for(".by_double_iso_label", conductor=N, iso_label=iso)),
            ('Minimal quadratic twist %s %s' % (data['minq_info'], data['minq_label']), url_for(".by_triple_label", conductor=minq_N, iso_label=minq_iso, number=minq_number)),
            ('All twists ', url_for(".rational_elliptic_curves", jinv=self.jinv)),
            ('L-function', url_for("l_functions.l_function_ec_page", label=self.lmfdb_label))]
        if not self.cm:
            if N<=300:
                self.friends += [('Symmetric square L-function', url_for("l_functions.l_function_ec_sym_page", power='2', label=self.lmfdb_iso))]
            if N<=50:
                self.friends += [('Symmetric cube L-function', url_for("l_functions.l_function_ec_sym_page", power='3', label=self.lmfdb_iso))]
        if self.newform_exists_in_db:
            self.friends += [('Modular form ' + self.newform_label, self.newform_link)]

        self.downloads = [('Download coefficients of q-expansion', url_for(".download_EC_qexp", label=self.lmfdb_label, limit=1000)),
                          ('Download all stored data', url_for(".download_EC_all", label=self.lmfdb_label)),
                          ('Download Magma code', url_for(".ec_code_download", conductor=cond, iso=iso, number=num, label=self.lmfdb_label, download_type='magma')),
                          ('Download Sage code', url_for(".ec_code_download", conductor=cond, iso=iso, number=num, label=self.lmfdb_label, download_type='sage')),
                          ('Download GP code', url_for(".ec_code_download", conductor=cond, iso=iso, number=num, label=self.lmfdb_label, download_type='gp'))
        ]

        try:
            self.plot = encode_plot(self.E.plot())
        except AttributeError:
            self.plot = encode_plot(EllipticCurve(data['ainvs']).plot())

        self.plot_link = '<img src="%s" width="200" height="150"/>' % self.plot
        self.properties = [('Label', self.lmfdb_label),
                           (None, self.plot_link),
                           ('Conductor', '\(%s\)' % data['conductor']),
                           ('Discriminant', '\(%s\)' % data['disc']),
                           ('j-invariant', '%s' % data['j_inv_latex']),
                           ('CM', '%s' % data['CM']),
                           ('Rank', '\(%s\)' % mw['rank']),
                           ('Torsion Structure', '\(%s\)' % mw['tor_struct'])
                           ]

        self.title = "Elliptic Curve %s (Cremona label %s)" % (self.lmfdb_label, self.label)

        self.bread = [('Elliptic Curves', url_for("ecnf.index")),
                           ('$\Q$', url_for(".rational_elliptic_curves")),
                           ('%s' % N, url_for(".by_conductor", conductor=N)),
                           ('%s' % iso, url_for(".by_double_iso_label", conductor=N, iso_label=iso)),
                           ('%s' % num,' ')]

    def code(self):
        if self._code == None:
            self.make_code_snippets()
        return self._code

    def make_code_snippets(self):
        # read in code.yaml from current directory:

        _curdir = os.path.dirname(os.path.abspath(__file__))
        self._code =  yaml.load(open(os.path.join(_curdir, "code.yaml")))

        # Fill in placeholders for this specific curve:

        for lang in ['sage', 'pari', 'magma']:
            self._code['curve'][lang] = self._code['curve'][lang] % (self.data['ainvs'],self.label)
        return
        for k in self._code:
            if k != 'prompt':
                for lang in self._code[k]:
                    self._code[k][lang] = self._code[k][lang].split("\n")
                    # remove final empty line
                    if len(self._code[k][lang][-1])==0:
                        self._code[k][lang] = self._code[k][lang][:-1]
Ejemplo n.º 7
0
def allgens(line):
    r""" Parses one line from an allgens file.  Returns the label and
    a dict containing fields with keys 'conductor', 'iso', 'number',
    'ainvs', 'jinv', 'cm', 'rank', 'gens', 'torsion_order', 'torsion_structure',
    'torsion_generators', all values being strings or ints, and more.

    Input line fields:

    conductor iso number ainvs rank torsion_structure gens torsion_gens

    Sample input line:

    20202 i 2 [1,0,0,-298389,54947169] 1 [2,4] [-570:6603:1] [-622:311:1] [834:19239:1]
    """
    global lmfdb_label_to_label
    global label_to_lmfdb_label

    data = split(line)
    iso = data[0] + data[1]
    label = iso + data[2]
    try:
        lmfdb_label = label_to_lmfdb_label[label]
    except AttributeError:
        print("Label {} not found in label_to_lmfdb_label dict!".format(label))
        lmfdb_label = ""

    global nallgens
    nallgens += 1
    if nallgens % 100 == 0:
        print("processing allgens for {} (#{})".format(label, nallgens))
    rank = int(data[4])
    t = data[5]
    tor_struct = [] if t == '[]' else t[1:-1].split(",")
    torsion = int(prod([int(ti) for ti in tor_struct], 1))
    ainvs = parse_ainvs(data[3])
    E = EllipticCurve(ainvs)
    jinv = text_type(E.j_invariant())
    if E.has_cm():
        cm = int(E.cm_discriminant())
    else:
        cm = int(0)
    N = E.conductor()
    bad_p = N.prime_factors()  # will be sorted
    num_bad_p = len(bad_p)

    local_data = [{
        'p':
        int(ld.prime().gen()),
        'ord_cond':
        int(ld.conductor_valuation()),
        'ord_disc':
        int(ld.discriminant_valuation()),
        'ord_den_j':
        int(max(0, -(E.j_invariant().valuation(ld.prime().gen())))),
        'red':
        int(ld.bad_reduction_type()),
        'rootno':
        int(E.root_number(ld.prime().gen())),
        'kod':
        web_latex(ld.kodaira_symbol()).replace('$', ''),
        'cp':
        int(ld.tamagawa_number())
    } for ld in E.local_data()]
    semistable = all([ld['ord_cond'] == 1 for ld in local_data])

    gens = [
        gen.replace("[", "(").replace("]", ")") for gen in data[6:6 + rank]
    ]
    tor_gens = ["%s" % parse_tgens(tgens[1:-1]) for tgens in data[6 + rank:]]

    from lmfdb.elliptic_curves.web_ec import parse_points
    heights = [float(E(P).height()) for P in parse_points(gens)]

    Etw, Dtw = E.minimal_quadratic_twist()
    if Etw.conductor() == N:
        min_quad_twist = {
            'label': label,
            'lmfdb_label': lmfdb_label,
            'disc': int(1)
        }
    else:
        minq_ainvs = Etw.ainvs()
        r = curves.lucky({
            'jinv': str(E.j_invariant()),
            'ainvs': minq_ainvs
        },
                         projection=['label', 'lmfdb_label'])
        min_quad_twist = {
            'label': r['label'],
            'lmfdb_label': r['lmfdb_label'],
            'disc': int(Dtw)
        }

    trace_hash = TraceHashClass(iso, E)

    return label, {
        'conductor': int(data[0]),
        'iso': iso,
        'number': int(data[2]),
        'ainvs': ainvs,
        'jinv': jinv,
        'cm': cm,
        'rank': rank,
        'gens': gens,
        'torsion': torsion,
        'torsion_structure': tor_struct,
        'torsion_generators': tor_gens,
        'trace_hash': trace_hash,
        'equation': web_latex(E),
        'bad_primes': bad_p,
        'num_bad_primes': num_bad_p,
        'local_data': local_data,
        'semistable': semistable,
        'signD': int(E.discriminant().sign()),
        'heights': heights,
        'aplist': E.aplist(100, python_ints=True),
        'anlist': E.anlist(20, python_ints=True),
        'min_quad_twist': min_quad_twist,
    }