Exemplo n.º 1
0
    def __call__(self, assumptions=None):
        """
        Run 'command' and collect output.

        INPUT:

        - ``assumptions`` - ignored, accepted for compatibility with
          other solvers (default: ``None``)

        TESTS:

        This class is not meant to be called directly::

            sage: from sage.sat.solvers.dimacs import DIMACS
            sage: fn = tmp_filename()
            sage: solver = DIMACS(filename=fn)
            sage: solver.add_clause( (1, -2 , 3) )
            sage: solver()
            Traceback (most recent call last):
            ...
            ValueError: No SAT solver command selected.
        """
        if assumptions is not None:
            raise NotImplementedError("Assumptions are not supported for DIMACS based solvers.")

        self.write()

        output_filename = None
        self._output = []

        command = self._command.strip()

        if not command:
            raise ValueError("No SAT solver command selected.")


        if "{output}" in command:
            output_filename = tmp_filename()
        command = command.format(input=self._headname, output=output_filename)

        args = shlex.split(command)

        try:
            process = subprocess.Popen(args, stdout=subprocess.PIPE)
        except OSError:
            raise OSError("Could run '%s', perhaps you need to add your SAT solver to $PATH?"%(" ".join(args)))

        try:
            while process.poll() is None:
                for line in iter(process.stdout.readline,''):
                    if get_verbose() or self._verbosity:
                        print line,
                        sys.stdout.flush()
                    self._output.append(line)
                sleep(0.1)
            if output_filename:
                self._output.extend(open(output_filename).readlines())
        except BaseException:
            process.kill()
            raise
Exemplo n.º 2
0
    def __call__(self, assumptions=None):
        """
        Run 'command' and collect output.

        INPUT:

        - ``assumptions`` - ignored, accepted for compatibility with
          other solvers (default: ``None``)

        TESTS:

        This class is not meant to be called directly::

            sage: from sage.sat.solvers.dimacs import DIMACS
            sage: fn = tmp_filename()
            sage: solver = DIMACS(filename=fn)
            sage: solver.add_clause( (1, -2 , 3) )
            sage: solver()
            Traceback (most recent call last):
            ...
            ValueError: No SAT solver command selected.
        """
        if assumptions is not None:
            raise NotImplementedError("Assumptions are not supported for DIMACS based solvers.")

        self.write()

        output_filename = None
        self._output = []

        command = self._command.strip()

        if not command:
            raise ValueError("No SAT solver command selected.")


        if "{output}" in command:
            output_filename = tmp_filename()
        command = command.format(input=self._headname, output=output_filename)

        args = shlex.split(command)

        try:
            process = subprocess.Popen(args, stdout=subprocess.PIPE)
        except OSError:
            raise OSError("Could run '%s', perhaps you need to add your SAT solver to $PATH?"%(" ".join(args)))

        try:
            while process.poll() is None:
                for line in iter(process.stdout.readline,''):
                    if get_verbose() or self._verbosity:
                        print(line)
                        sys.stdout.flush()
                    self._output.append(line)
                sleep(0.1)
            if output_filename:
                self._output.extend(open(output_filename).readlines())
        except BaseException:
            process.kill()
            raise
Exemplo n.º 3
0
    def series(self, n=2, quadratic_twist=+1, prec=5):
        r"""
        Returns the `n`-th approximation to the `p`-adic L-series as a
        power series in `T` (corresponding to `\gamma-1` with
        `\gamma=1+p` as a generator of `1+p\ZZ_p`).  Each coefficient
        is a `p`-adic number whose precision is provably correct.

        Here the normalization of the `p`-adic L-series is chosen such
        that `L_p(J,1) = (1-1/\alpha)^2 L(J,1)/\Omega_J` where
        `\alpha` is the unit root

        INPUT:

            - ``n`` - (default: 2) a positive integer
            - ``quadratic_twist`` - (default: +1) a fundamental
              discriminant of a quadratic field, coprime to the
              conductor of the curve
            - ``prec`` - (default: 5) maximal number of terms of the
              series to compute; to compute as many as possible just
              give a very large number for ``prec``; the result will
              still be correct.

        ALIAS: power_series is identical to series.

        EXAMPLES::

        sage: J = J0(188)[0]
        sage: p = 7
        sage: L = J.padic_lseries(p)
        sage: L.is_ordinary()
        True
        sage: f = L.series(2)
        sage: f[0]
        O(7^20)
        sage: f[1].norm()
        3 + 4*7 + 3*7^2 + 6*7^3 + 5*7^4 + 5*7^5 + 6*7^6 + 4*7^7 + 5*7^8 + 7^10 + 5*7^11 + 4*7^13 + 4*7^14 + 5*7^15 + 2*7^16 + 5*7^17 + 7^18 + 7^19 + O(7^20)

        """
        n = ZZ(n)
        if n < 1:
            raise ValueError("n (={0}) must be a positive integer".format(n))
        if not self.is_ordinary():
            raise ValueError("p (={0}) must be an ordinary prime".format(
                self._p))
        # check if the conditions on quadratic_twist are satisfied
        D = ZZ(quadratic_twist)
        if D != 1:
            if D % 4 == 0:
                d = D // 4
                if not d.is_squarefree() or d % 4 == 1:
                    raise ValueError(
                        "quadratic_twist (={0}) must be a fundamental discriminant of a quadratic field"
                        .format(D))
            else:
                if not D.is_squarefree() or D % 4 != 1:
                    raise ValueError(
                        "quadratic_twist (={0}) must be a fundamental discriminant of a quadratic field"
                        .format(D))
            if gcd(D, self._p) != 1:
                raise ValueError(
                    "quadratic twist (={0}) must be coprime to p (={1}) ".
                    format(D, self._p))
            if gcd(D, self._E.conductor()) != 1:
                for ell in prime_divisors(D):
                    if valuation(self._E.conductor(), ell) > valuation(D, ell):
                        raise ValueError(
                            "can not twist a curve of conductor (={0}) by the quadratic twist (={1})."
                            .format(self._E.conductor(), D))

        p = self._p
        if p == 2 and self._normalize:
            print('Warning : For p=2 the normalization might not be correct !')
        #verbose("computing L-series for p=%s, n=%s, and prec=%s"%(p,n,prec))

#        bounds = self._prec_bounds(n,prec)
#        padic_prec = max(bounds[1:]) + 5
        padic_prec = 10
        #        verbose("using p-adic precision of %s"%padic_prec)

        res_series_prec = min(p**(n - 1), prec)
        verbose("using series precision of %s" % res_series_prec)

        ans = self._get_series_from_cache(n, res_series_prec, D)
        if not ans is None:
            verbose("found series in cache")
            return ans

        K = QQ
        gamma = K(1 + p)
        R = PowerSeriesRing(K, 'T', res_series_prec)
        T = R(R.gen(), res_series_prec)
        #L = R(0)
        one_plus_T_factor = R(1)
        gamma_power = K(1)
        teich = self.teichmuller(padic_prec)
        p_power = p**(n - 1)
        #        F = Qp(p,padic_prec)

        verbose("Now iterating over %s summands" % ((p - 1) * p_power))
        verbose_level = get_verbose()
        count_verb = 0
        alphas = self.alpha()
        #print len(alphas)
        Lprod = []
        self._emb = 0
        if len(alphas) == 2:
            split = True
        else:
            split = False
        for alpha in alphas:
            L = R(0)
            self._emb = self._emb + 1
            for j in range(p_power):
                s = K(0)
                if verbose_level >= 2 and j / p_power * 100 > count_verb + 3:
                    verbose("%.2f percent done" % (float(j) / p_power * 100))
                    count_verb += 3
                for a in range(1, p):
                    if split:
                        b = (teich[a]) % ZZ(p**n)
                        b = b * gamma_power
                    else:
                        b = teich[a] * gamma_power
                    s += self.measure(b, n, padic_prec, D, alpha)
                L += s * one_plus_T_factor
                one_plus_T_factor *= 1 + T
                gamma_power *= gamma

            Lprod = Lprod + [L]
        if len(Lprod) == 1:
            return Lprod[0]
        else:
            return Lprod[0] * Lprod[1]
Exemplo n.º 4
0
    def series(self, n=2, quadratic_twist=+1, prec=5):
        r"""
        Returns the `n`-th approximation to the `p`-adic L-series as a
        power series in `T` (corresponding to `\gamma-1` with
        `\gamma=1+p` as a generator of `1+p\ZZ_p`).  Each coefficient
        is a `p`-adic number whose precision is provably correct.
        
        Here the normalization of the `p`-adic L-series is chosen such
        that `L_p(J,1) = (1-1/\alpha)^2 L(J,1)/\Omega_J` where
        `\alpha` is the unit root

        INPUT:
        
            - ``n`` - (default: 2) a positive integer
            - ``quadratic_twist`` - (default: +1) a fundamental
              discriminant of a quadratic field, coprime to the
              conductor of the curve
            - ``prec`` - (default: 5) maximal number of terms of the
              series to compute; to compute as many as possible just
              give a very large number for ``prec``; the result will
              still be correct.

        ALIAS: power_series is identical to series.

        EXAMPLES:

	    sage: J = J0(188)[0]
	    sage: p = 7
	    sage: L = J.padic_lseries(p)
	    sage: L.is_ordinary()
	    True
	    sage: f = L.series(2)
	    sage: f[0]
	    O(7^20)
	    sage: f[1].norm()
	    3 + 4*7 + 3*7^2 + 6*7^3 + 5*7^4 + 5*7^5 + 6*7^6 + 4*7^7 + 5*7^8 + 7^10 + 5*7^11 + 4*7^13 + 4*7^14 + 5*7^15 + 2*7^16 + 5*7^17 + 7^18 + 7^19 + O(7^20)

        """
        n = ZZ(n)
        if n < 1:
            raise ValueError, "n (=%s) must be a positive integer"%n
        if not self.is_ordinary():
            raise ValueError, "p (=%s) must be an ordinary prime"%p
        # check if the conditions on quadratic_twist are satisfied
        D = ZZ(quadratic_twist)
        if D != 1:
            if D % 4 == 0:
                d = D//4
                if not d.is_squarefree() or d % 4 == 1:
                    raise ValueError, "quadratic_twist (=%s) must be a fundamental discriminant of a quadratic field"%D
            else:
                if not D.is_squarefree() or D % 4 != 1:
                    raise ValueError, "quadratic_twist (=%s) must be a fundamental discriminant of a quadratic field"%D
            if gcd(D,self._p) != 1:
                raise ValueError, "quadratic twist (=%s) must be coprime to p (=%s) "%(D,self._p)
            if gcd(D,self._E.conductor())!= 1:
                for ell in prime_divisors(D):
                    if valuation(self._E.conductor(),ell) > valuation(D,ell) :
                        raise ValueError, "can not twist a curve of conductor (=%s) by the quadratic twist (=%s)."%(self._E.conductor(),D)
                    
            
        p = self._p
        if p == 2 and self._normalize :
            print 'Warning : For p=2 the normalization might not be correct !'
        #verbose("computing L-series for p=%s, n=%s, and prec=%s"%(p,n,prec))
        
#        bounds = self._prec_bounds(n,prec)
#        padic_prec = max(bounds[1:]) + 5
        padic_prec = 10
#        verbose("using p-adic precision of %s"%padic_prec)
        
        res_series_prec = min(p**(n-1), prec)
        verbose("using series precision of %s"%res_series_prec)
        
        ans = self._get_series_from_cache(n, res_series_prec,D)
        if not ans is None:
            verbose("found series in cache")
            return ans
 
        K = QQ
        gamma = K(1 + p)
        R = PowerSeriesRing(K,'T',res_series_prec)
        T = R(R.gen(),res_series_prec )
        #L = R(0) 
        one_plus_T_factor = R(1) 
        gamma_power = K(1)
        teich = self.teichmuller(padic_prec)
        p_power = p**(n-1)
#        F = Qp(p,padic_prec)

        verbose("Now iterating over %s summands"%((p-1)*p_power))
        verbose_level = get_verbose()
        count_verb = 0
        alphas = self.alpha()
        #print len(alphas)
        Lprod = []
        self._emb = 0
        if len(alphas) == 2:
            split = True
        else:
            split = False
        for alpha in alphas:
            L = R(0)
            self._emb = self._emb + 1
            for j in range(p_power):
                s = K(0)
                if verbose_level >= 2 and j/p_power*100 > count_verb + 3:
                    verbose("%.2f percent done"%(float(j)/p_power*100))
                    count_verb += 3
                for a in range(1,p):
                    if split:
#                        b = ((F.teichmuller(a)).lift() % ZZ(p**n))
                        b = (teich[a]) % ZZ(p**n)
                        b = b*gamma_power
                    else:
                        b = teich[a] * gamma_power
                    s += self.measure(b, n, padic_prec,D,alpha)
                L += s * one_plus_T_factor
                one_plus_T_factor *= 1+T
                gamma_power *= gamma
            
            Lprod = Lprod + [L]
        if len(Lprod)==1:
            return Lprod[0]
        else:
            return Lprod[0]*Lprod[1]