def _d(n, j, prec, sq23pi, sqrt8): """ Compute the sinh term in the outer sum of the HRR formula. The constants sqrt(2/3*pi) and sqrt(8) must be precomputed. """ j = from_int(j) pi = mpf_pi(prec) a = mpf_div(sq23pi, j, prec) b = mpf_sub(from_int(n), from_rational(1, 24, prec), prec) c = mpf_sqrt(b, prec) ch, sh = mpf_cosh_sinh(mpf_mul(a, c), prec) D = mpf_div(mpf_sqrt(j, prec), mpf_mul(mpf_mul(sqrt8, b), pi), prec) E = mpf_sub(mpf_mul(a, ch), mpf_div(sh, c, prec), prec) return mpf_mul(D, E)
def _create_evalf_table(): global evalf_table from sympy.functions.combinatorial.numbers import bernoulli from sympy.concrete.products import Product from sympy.concrete.summations import Sum from sympy.core.add import Add from sympy.core.mul import Mul from sympy.core.numbers import Exp1, Float, Half, ImaginaryUnit, Integer, NaN, NegativeOne, One, Pi, Rational, Zero from sympy.core.power import Pow from sympy.core.symbol import Dummy, Symbol from sympy.functions.elementary.complexes import Abs, im, re from sympy.functions.elementary.exponential import exp, log from sympy.functions.elementary.integers import ceiling, floor from sympy.functions.elementary.piecewise import Piecewise from sympy.functions.elementary.trigonometric import atan, cos, sin from sympy.integrals.integrals import Integral evalf_table = { Symbol: evalf_symbol, Dummy: evalf_symbol, Float: lambda x, prec, options: (x._mpf_, None, prec, None), Rational: lambda x, prec, options: (from_rational(x.p, x.q, prec), None, prec, None), Integer: lambda x, prec, options: (from_int(x.p, prec), None, prec, None), Zero: lambda x, prec, options: (None, None, prec, None), One: lambda x, prec, options: (fone, None, prec, None), Half: lambda x, prec, options: (fhalf, None, prec, None), Pi: lambda x, prec, options: (mpf_pi(prec), None, prec, None), Exp1: lambda x, prec, options: (mpf_e(prec), None, prec, None), ImaginaryUnit: lambda x, prec, options: (None, fone, None, prec), NegativeOne: lambda x, prec, options: (fnone, None, prec, None), NaN: lambda x, prec, options: (fnan, None, prec, None), exp: lambda x, prec, options: evalf_pow( Pow(S.Exp1, x.args[0], evaluate=False), prec, options), cos: evalf_trig, sin: evalf_trig, Add: evalf_add, Mul: evalf_mul, Pow: evalf_pow, log: evalf_log, atan: evalf_atan, Abs: evalf_abs, re: evalf_re, im: evalf_im, floor: evalf_floor, ceiling: evalf_ceiling, Integral: evalf_integral, Sum: evalf_sum, Product: evalf_prod, Piecewise: evalf_piecewise, bernoulli: evalf_bernoulli, }
def _create_evalf_table(): global evalf_table from ..functions.combinatorial.numbers import bernoulli from ..concrete.products import Product from ..concrete.summations import Sum from .add import Add from .mul import Mul from .numbers import (Exp1, Float, Half, ImaginaryUnit, Integer, NaN, NegativeOne, One, Pi, Rational, Zero) from .power import Pow from .symbol import Dummy, Symbol from ..functions.elementary.complexes import Abs, im, re from ..functions.elementary.exponential import log from ..functions.elementary.piecewise import Piecewise from ..functions.elementary.trigonometric import atan, cos, sin from ..integrals.integrals import Integral evalf_table = { Symbol: evalf_symbol, Dummy: evalf_symbol, Float: lambda x, prec, options: (x._mpf_, None, prec if prec <= x._prec else x._prec, None), Rational: lambda x, prec, options: (from_rational(x.numerator, x.denominator, prec), None, prec, None), Integer: lambda x, prec, options: (from_int(x.numerator, prec), None, prec, None), Zero: lambda x, prec, options: (None, None, prec, None), One: lambda x, prec, options: (fone, None, prec, None), Half: lambda x, prec, options: (fhalf, None, prec, None), Pi: lambda x, prec, options: (mpf_pi(prec), None, prec, None), Exp1: lambda x, prec, options: (mpf_e(prec), None, prec, None), ImaginaryUnit: lambda x, prec, options: (None, fone, None, prec), NegativeOne: lambda x, prec, options: (fnone, None, prec, None), NaN: lambda x, prec, options: (fnan, None, prec, None), cos: evalf_trig, sin: evalf_trig, Add: evalf_add, Mul: evalf_mul, Pow: evalf_pow, log: evalf_log, atan: evalf_atan, Abs: evalf_abs, re: evalf_re, im: evalf_im, Integral: evalf_integral, Sum: evalf_sum, Product: evalf_prod, Piecewise: evalf_piecewise, bernoulli: evalf_bernoulli, }
def _convert_tol(ctx, tol): if isinstance(tol, int_types): return from_int(tol) if isinstance(tol, float): return from_float(tol) if hasattr(tol, "_mpf_"): return tol._mpf_ prec, rounding = ctx._prec_rounding if isinstance(tol, string_types): return from_str(tol, prec, rounding) raise ValueError("expected a real number, got %s" % tol)
def npartitions(n, verbose=False): """ Calculate the partition function P(n), i.e. the number of ways that n can be written as a sum of positive integers. P(n) is computed using the Hardy-Ramanujan-Rademacher formula [1]_. The correctness of this implementation has been tested through 10**10. Examples ======== >>> from sympy.ntheory import npartitions >>> npartitions(25) 1958 References ========== .. [1] http://mathworld.wolfram.com/PartitionFunctionP.html """ n = int(n) if n < 0: return 0 if n <= 5: return [1, 1, 2, 3, 5, 7][n] if '_factor' not in globals(): _pre() # Estimate number of bits in p(n). This formula could be tidied pbits = int(( math.pi*(2*n/3.)**0.5 - math.log(4*n))/math.log(10) + 1) * \ math.log(10, 2) prec = p = int(pbits*1.1 + 100) s = fzero M = max(6, int(0.24*n**0.5 + 4)) if M > 10**5: raise ValueError("Input too big") # Corresponds to n > 1.7e11 sq23pi = mpf_mul(mpf_sqrt(from_rational(2, 3, p), p), mpf_pi(p), p) sqrt8 = mpf_sqrt(from_int(8), p) for q in range(1, M): a = _a(n, q, p) d = _d(n, q, p, sq23pi, sqrt8) s = mpf_add(s, mpf_mul(a, d), prec) if verbose: print("step", q, "of", M, to_str(a, 10), to_str(d, 10)) # On average, the terms decrease rapidly in magnitude. # Dynamically reducing the precision greatly improves # performance. p = bitcount(abs(to_int(d))) + 50 return int(to_int(mpf_add(s, fhalf, prec)))
def _to_mpmath(self, prec, allow_ints=True): # mpmath functions accept ints as input errmsg = "cannot convert to mpmath number" if allow_ints and self.is_Integer: return self.p if hasattr(self, '_as_mpf_val'): return make_mpf(self._as_mpf_val(prec)) try: re, im, _, _ = evalf(self, prec, {}) if im: if not re: re = fzero return make_mpc((re, im)) elif re: return make_mpf(re) else: return make_mpf(fzero) except NotImplementedError: v = self._eval_evalf(prec) if v is None: raise ValueError(errmsg) if v.is_Float: return make_mpf(v._mpf_) # Number + Number*I is also fine re, im = v.as_real_imag() if allow_ints and re.is_Integer: re = from_int(re.p) elif re.is_Float: re = re._mpf_ else: raise ValueError(errmsg) if allow_ints and im.is_Integer: im = from_int(im.p) elif im.is_Float: im = im._mpf_ else: raise ValueError(errmsg) return make_mpc((re, im))
def calc_part(expr, nexpr): nint = int(to_int(nexpr, rnd)) n, c, p, b = nexpr if (c != 1 and p != 0) or p < 0: expr = C.Add(expr, -nint, evaluate=False) x, _, x_acc, _ = evalf(expr, 10, options) try: check_target(expr, (x, None, x_acc, None), 3) except PrecisionExhausted: if not expr.equals(0): raise PrecisionExhausted x = fzero nint += int(no*(mpf_cmp(x or fzero, fzero) == no)) nint = from_int(nint) return nint, fastlog(nint) + 10
def _create_evalf_table(): global evalf_table evalf_table = { C.Symbol: evalf_symbol, C.Dummy: evalf_symbol, C.Float: lambda x, prec, options: (x._mpf_, None, prec, None), C.Rational: lambda x, prec, options: (from_rational(x.p, x.q, prec), None, prec, None), C.Integer: lambda x, prec, options: (from_int(x.p, prec), None, prec, None), C.Zero: lambda x, prec, options: (None, None, prec, None), C.One: lambda x, prec, options: (fone, None, prec, None), C.Half: lambda x, prec, options: (fhalf, None, prec, None), C.Pi: lambda x, prec, options: (mpf_pi(prec), None, prec, None), C.Exp1: lambda x, prec, options: (mpf_e(prec), None, prec, None), C.ImaginaryUnit: lambda x, prec, options: (None, fone, None, prec), C.NegativeOne: lambda x, prec, options: (fnone, None, prec, None), C.NaN : lambda x, prec, options: (fnan, None, prec, None), C.exp: lambda x, prec, options: evalf_pow(C.Pow(S.Exp1, x.args[0], evaluate=False), prec, options), C.cos: evalf_trig, C.sin: evalf_trig, C.Add: evalf_add, C.Mul: evalf_mul, C.Pow: evalf_pow, C.log: evalf_log, C.atan: evalf_atan, C.Abs: evalf_abs, C.re: evalf_re, C.im: evalf_im, C.floor: evalf_floor, C.ceiling: evalf_ceiling, C.Integral: evalf_integral, C.Sum: evalf_sum, C.Product: evalf_prod, C.Piecewise: evalf_piecewise, C.bernoulli: evalf_bernoulli, }
def npartitions(n): """Calculate the partition function P(n), i.e. the number of ways that n can be written as a sum of positive integers. P(n) is computed using the Hardy-Ramanujan-Rademacher formula. The correctness of this implementation has been tested for 10**n up to n = 8. Examples ======== >>> npartitions(25) 1958 References ========== * http://mathworld.wolfram.com/PartitionFunctionP.html """ n = int(n) if n < 0: return 0 if n <= 5: return [1, 1, 2, 3, 5, 7][n] # Estimate number of bits in p(n). This formula could be tidied pbits = int((math.pi*(2*n/3.)**0.5 - math.log(4*n))/math.log(10) + 1) * \ math.log(10, 2) prec = p = int(pbits*1.1 + 100) s = fzero M = max(6, int(0.24*n**0.5 + 4)) sq23pi = mpf_mul(mpf_sqrt(from_rational(2, 3, p), p), mpf_pi(p), p) sqrt8 = mpf_sqrt(from_int(8), p) for q in range(1, M): a = _a(n, q, p) d = _d(n, q, p, sq23pi, sqrt8) s = mpf_add(s, mpf_mul(a, d), prec) debug("step", q, "of", M, to_str(a, 10), to_str(d, 10)) # On average, the terms decrease rapidly in magnitude. Dynamically # reducing the precision greatly improves performance. p = bitcount(abs(to_int(d))) + 50 return int(to_int(mpf_add(s, fhalf, prec)))
def calc_part(expr, nexpr): from sympy.core.add import Add nint = int(to_int(nexpr, rnd)) n, c, p, b = nexpr is_int = (p == 0) if not is_int: # if there are subs and they all contain integer re/im parts # then we can (hopefully) safely substitute them into the # expression s = options.get('subs', False) if s: doit = True from sympy.core.compatibility import as_int for v in s.values(): try: as_int(v) except ValueError: try: [as_int(i) for i in v.as_real_imag()] continue except (ValueError, AttributeError): doit = False break if doit: expr = expr.subs(s) expr = Add(expr, -nint, evaluate=False) x, _, x_acc, _ = evalf(expr, 10, options) try: check_target(expr, (x, None, x_acc, None), 3) except PrecisionExhausted: if not expr.equals(0): raise PrecisionExhausted x = fzero nint += int(no*(mpf_cmp(x or fzero, fzero) == no)) nint = from_int(nint) return nint, fastlog(nint) + 10
def _a(n, k, prec): """ Compute the inner sum in HRR formula [1]_ References ========== .. [1] http://msp.org/pjm/1956/6-1/pjm-v6-n1-p18-p.pdf """ if k == 1: return fone k1 = k e = 0 p = _factor[k] while k1 % p == 0: k1 //= p e += 1 k2 = k//k1 # k2 = p^e v = 1 - 24*n pi = mpf_pi(prec) if k1 == 1: # k = p^e if p == 2: mod = 8*k v = mod + v % mod v = (v*pow(9, k - 1, mod)) % mod m = _sqrt_mod_prime_power(v, 2, e + 3)[0] arg = mpf_div(mpf_mul( from_int(4*m), pi, prec), from_int(mod), prec) return mpf_mul(mpf_mul( from_int((-1)**e*jacobi_symbol(m - 1, m)), mpf_sqrt(from_int(k), prec), prec), mpf_sin(arg, prec), prec) if p == 3: mod = 3*k v = mod + v % mod if e > 1: v = (v*pow(64, k//3 - 1, mod)) % mod m = _sqrt_mod_prime_power(v, 3, e + 1)[0] arg = mpf_div(mpf_mul(from_int(4*m), pi, prec), from_int(mod), prec) return mpf_mul(mpf_mul( from_int(2*(-1)**(e + 1)*legendre_symbol(m, 3)), mpf_sqrt(from_int(k//3), prec), prec), mpf_sin(arg, prec), prec) v = k + v % k if v % p == 0: if e == 1: return mpf_mul( from_int(jacobi_symbol(3, k)), mpf_sqrt(from_int(k), prec), prec) return fzero if not is_quad_residue(v, p): return fzero _phi = p**(e - 1)*(p - 1) v = (v*pow(576, _phi - 1, k)) m = _sqrt_mod_prime_power(v, p, e)[0] arg = mpf_div( mpf_mul(from_int(4*m), pi, prec), from_int(k), prec) return mpf_mul(mpf_mul( from_int(2*jacobi_symbol(3, k)), mpf_sqrt(from_int(k), prec), prec), mpf_cos(arg, prec), prec) if p != 2 or e >= 3: d1, d2 = igcd(k1, 24), igcd(k2, 24) e = 24//(d1*d2) n1 = ((d2*e*n + (k2**2 - 1)//d1)* pow(e*k2*k2*d2, _totient[k1] - 1, k1)) % k1 n2 = ((d1*e*n + (k1**2 - 1)//d2)* pow(e*k1*k1*d1, _totient[k2] - 1, k2)) % k2 return mpf_mul(_a(n1, k1, prec), _a(n2, k2, prec), prec) if e == 2: n1 = ((8*n + 5)*pow(128, _totient[k1] - 1, k1)) % k1 n2 = (4 + ((n - 2 - (k1**2 - 1)//8)*(k1**2)) % 4) % 4 return mpf_mul(mpf_mul( from_int(-1), _a(n1, k1, prec), prec), _a(n2, k2, prec)) n1 = ((8*n + 1)*pow(32, _totient[k1] - 1, k1)) % k1 n2 = (2 + (n - (k1**2 - 1)//8) % 2) % 2 return mpf_mul(_a(n1, k1, prec), _a(n2, k2, prec), prec)
def _a(n, k, prec): """ Compute the inner sum in HRR formula [1]_ References ========== .. [1] http://msp.org/pjm/1956/6-1/pjm-v6-n1-p18-p.pdf """ if k == 1: return fone k1 = k e = 0 p = _factor[k] while k1 % p == 0: k1 //= p e += 1 k2 = k // k1 # k2 = p^e v = 1 - 24 * n pi = mpf_pi(prec) if k1 == 1: # k = p^e if p == 2: mod = 8 * k v = mod + v % mod v = (v * pow(9, k - 1, mod)) % mod m = _sqrt_mod_prime_power(v, 2, e + 3)[0] arg = mpf_div(mpf_mul(from_int(4 * m), pi, prec), from_int(mod), prec) return mpf_mul( mpf_mul(from_int((-1)**e * jacobi_symbol(m - 1, m)), mpf_sqrt(from_int(k), prec), prec), mpf_sin(arg, prec), prec) if p == 3: mod = 3 * k v = mod + v % mod if e > 1: v = (v * pow(64, k // 3 - 1, mod)) % mod m = _sqrt_mod_prime_power(v, 3, e + 1)[0] arg = mpf_div(mpf_mul(from_int(4 * m), pi, prec), from_int(mod), prec) return mpf_mul( mpf_mul(from_int(2 * (-1)**(e + 1) * legendre_symbol(m, 3)), mpf_sqrt(from_int(k // 3), prec), prec), mpf_sin(arg, prec), prec) v = k + v % k if v % p == 0: if e == 1: return mpf_mul(from_int(jacobi_symbol(3, k)), mpf_sqrt(from_int(k), prec), prec) return fzero if not is_quad_residue(v, p): return fzero _phi = p**(e - 1) * (p - 1) v = (v * pow(576, _phi - 1, k)) m = _sqrt_mod_prime_power(v, p, e)[0] arg = mpf_div(mpf_mul(from_int(4 * m), pi, prec), from_int(k), prec) return mpf_mul( mpf_mul(from_int(2 * jacobi_symbol(3, k)), mpf_sqrt(from_int(k), prec), prec), mpf_cos(arg, prec), prec) if p != 2 or e >= 3: d1, d2 = igcd(k1, 24), igcd(k2, 24) e = 24 // (d1 * d2) n1 = ((d2 * e * n + (k2**2 - 1) // d1) * pow(e * k2 * k2 * d2, _totient[k1] - 1, k1)) % k1 n2 = ((d1 * e * n + (k1**2 - 1) // d2) * pow(e * k1 * k1 * d1, _totient[k2] - 1, k2)) % k2 return mpf_mul(_a(n1, k1, prec), _a(n2, k2, prec), prec) if e == 2: n1 = ((8 * n + 5) * pow(128, _totient[k1] - 1, k1)) % k1 n2 = (4 + ((n - 2 - (k1**2 - 1) // 8) * (k1**2)) % 4) % 4 return mpf_mul(mpf_mul(from_int(-1), _a(n1, k1, prec), prec), _a(n2, k2, prec)) n1 = ((8 * n + 1) * pow(32, _totient[k1] - 1, k1)) % k1 n2 = (2 + (n - (k1**2 - 1) // 8) % 2) % 2 return mpf_mul(_a(n1, k1, prec), _a(n2, k2, prec), prec)
def _create_evalf_table(): global evalf_table evalf_table = { C.Symbol: evalf_symbol, C.Dummy: evalf_symbol, C.Float: lambda x, prec, options: (x._mpf_, None, prec, None), C.Rational: lambda x, prec, options: (from_rational(x.p, x.q, prec), None, prec, None), C.Integer: lambda x, prec, options: (from_int(x.p, prec), None, prec, None), C.Zero: lambda x, prec, options: (None, None, prec, None), C.One: lambda x, prec, options: (fone, None, prec, None), C.Half: lambda x, prec, options: (fhalf, None, prec, None), C.Pi: lambda x, prec, options: (mpf_pi(prec), None, prec, None), C.Exp1: lambda x, prec, options: (mpf_e(prec), None, prec, None), C.ImaginaryUnit: lambda x, prec, options: (None, fone, None, prec), C.NegativeOne: lambda x, prec, options: (fnone, None, prec, None), C.NaN: lambda x, prec, options: (fnan, None, prec, None), C.exp: lambda x, prec, options: evalf_pow( C.Pow(S.Exp1, x.args[0], evaluate=False), prec, options), C.cos: evalf_trig, C.sin: evalf_trig, C.Add: evalf_add, C.Mul: evalf_mul, C.Pow: evalf_pow, C.log: evalf_log, C.atan: evalf_atan, C.Abs: evalf_abs, C.re: evalf_re, C.im: evalf_im, C.floor: evalf_floor, C.ceiling: evalf_ceiling, C.Integral: evalf_integral, C.Sum: evalf_sum, C.Product: evalf_prod, C.Piecewise: evalf_piecewise, C.bernoulli: evalf_bernoulli, }