def mpc_besseljn(n, z, prec, rounding=round_fast):
negate = n < 0 and n & 1
n = abs(n)
origprec = prec
zre, zim = z
mag = max(zre[2]+zre[3], zim[2]+zim[3])
prec += 20 + n*bitcount(n) + abs(mag)
if mag < 0:
prec -= n * mag
zre = to_fixed(zre, prec)
zim = to_fixed(zim, prec)
z2re = (zre**2 - zim**2) >> prec
z2im = (zre*zim) >> (prec-1)
if not n:
sre = tre = MPZ_ONE << prec
sim = tim = MPZ_ZERO
else:
re, im = complex_int_pow(zre, zim, n)
sre = tre = (re // ifac(n)) >> ((n-1)*prec + n)
sim = tim = (im // ifac(n)) >> ((n-1)*prec + n)
k = 1
while abs(tre) + abs(tim) > 3:
p = -4*k*(k+n)
tre, tim = tre*z2re - tim*z2im, tim*z2re + tre*z2im
tre = (tre // p) >> prec
tim = (tim // p) >> prec
sre += tre
sim += tim
k += 1
if negate:
sre = -sre
sim = -sim
re = from_man_exp(sre, -prec, origprec, rounding)
im = from_man_exp(sim, -prec, origprec, rounding)
return (re, im)
def mpc_zeta(s, prec, rnd):
re, im = s
wp = prec + 20
n = int(wp / 2.54 + 5)
n += int(0.9 * abs(to_int(im)))
d = borwein_coefficients(n)
ref = to_fixed(re, wp)
imf = to_fixed(im, wp)
tre = MP_ZERO
tim = MP_ZERO
one = MP_ONE << wp
one_2wp = MP_ONE << (2 * wp)
critical_line = re == fhalf
for k in xrange(n):
log = log_int_fixed(k + 1, wp)
# A square root is much cheaper than an exp
if critical_line:
w = one_2wp // sqrt_fixed((k + 1) << wp, wp)
else:
w = to_fixed(mpf_exp(from_man_exp(-ref * log, -2 * wp), wp), wp)
if k & 1:
w *= (d[n] - d[k])
else:
w *= (d[k] - d[n])
wre, wim = cos_sin(
from_man_exp(-imf * log_int_fixed(k + 1, wp), -2 * wp), wp)
tre += (w * to_fixed(wre, wp)) >> wp
tim += (w * to_fixed(wim, wp)) >> wp
tre //= (-d[n])
tim //= (-d[n])
tre = from_man_exp(tre, -wp, wp)
tim = from_man_exp(tim, -wp, wp)
q = mpc_sub(mpc_one, mpc_pow(mpc_two, mpc_sub(mpc_one, s, wp), wp), wp)
return mpc_div((tre, tim), q, prec, rnd)
def mpc_ci_si_taylor(re, im, wp, which=0):
# The following code is only designed for small arguments,
# and not too small arguments (for relative accuracy)
if re[1]:
mag = re[2]+re[3]
elif im[1]:
mag = im[2]+im[3]
if im[1]:
mag = max(mag, im[2]+im[3])
if mag > 2 or mag < -wp:
raise NotImplementedError
wp += (2-mag)
zre = to_fixed(re, wp)
zim = to_fixed(im, wp)
z2re = (zim*zim-zre*zre)>>wp
z2im = (-2*zre*zim)>>wp
tre = zre
tim = zim
one = MPZ_ONE<<wp
if which == 0:
sre, sim, tre, tim, k = 0, 0, (MPZ_ONE<<wp), 0, 2
else:
sre, sim, tre, tim, k = zre, zim, zre, zim, 3
while max(abs(tre), abs(tim)) > 2:
f = k*(k-1)
tre, tim = ((tre*z2re-tim*z2im)//f)>>wp, ((tre*z2im+tim*z2re)//f)>>wp
sre += tre//k
sim += tim//k
k += 2
return from_man_exp(sre, -wp), from_man_exp(sim, -wp)
def mpf_psi0(x, prec, rnd=round_fast):
"""
Computation of the digamma function (psi function of order 0)
of a real argument.
"""
sign, man, exp, bc = x
wp = prec + 10
if not man:
if x == finf:
return x
if x == fninf or x == fnan:
return fnan
if x == fzero or (exp >= 0 and sign):
raise ValueError("polygamma pole")
# Reflection formula
if sign and exp + bc > 3:
c, s = mpf_cos_sin_pi(x, wp)
q = mpf_mul(mpf_div(c, s, wp), mpf_pi(wp), wp)
p = mpf_psi0(mpf_sub(fone, x, wp), wp)
return mpf_sub(p, q, prec, rnd)
# The logarithmic term is accurate enough
if (not sign) and bc + exp > wp:
return mpf_log(mpf_sub(x, fone, wp), prec, rnd)
# Initial recurrence to obtain a large enough x
m = to_int(x)
n = int(0.11 * wp) + 2
s = MP_ZERO
x = to_fixed(x, wp)
one = MP_ONE << wp
if m < n:
for k in xrange(m, n):
s -= (one << wp) // x
x += one
x -= one
# Logarithmic term
s += to_fixed(mpf_log(from_man_exp(x, -wp, wp), wp), wp)
# Endpoint term in Euler-Maclaurin expansion
s += (one << wp) // (2 * x)
# Euler-Maclaurin remainder sum
x2 = (x * x) >> wp
t = one
prev = 0
k = 1
while 1:
t = (t * x2) >> wp
bsign, bman, bexp, bbc = mpf_bernoulli(2 * k, wp)
offset = bexp + 2 * wp
if offset >= 0:
term = (bman << offset) // (t * (2 * k))
else:
term = (bman >> (-offset)) // (t * (2 * k))
if k & 1:
s -= term
else:
s += term
if k > 2 and term >= prev:
break
prev = term
k += 1
return from_man_exp(s, -wp, wp, rnd)
def mpc_pow_int(z, n, prec, rnd=round_fast):
if n == 0: return mpc_one
if n == 1: return mpc_pos(z, prec, rnd)
if n == 2: return mpc_mul(z, z, prec, rnd)
if n == -1: return mpc_div(mpc_one, z, prec, rnd)
if n < 0: return mpc_div(mpc_one, mpc_pow_int(z, -n, prec+4), prec, rnd)
a, b = z
asign, aman, aexp, abc = a
bsign, bman, bexp, bbc = b
if asign: aman = -aman
if bsign: bman = -bman
de = aexp - bexp
abs_de = abs(de)
exact_size = n*(abs_de + max(abc, bbc))
if exact_size < 10000:
if de > 0:
aman <<= de
aexp = bexp
else:
bman <<= (-de)
bexp = aexp
re, im = complex_int_pow(aman, bman, n)
re = from_man_exp(re, int(n*aexp), prec, rnd)
im = from_man_exp(im, int(n*bexp), prec, rnd)
return re, im
return mpc_exp(mpc_mul_int(mpc_log(z, prec+10), n, prec+10), prec, rnd)
def mpc_pow_int(z, n, prec, rnd=round_fast):
if n == 0: return mpc_one
if n == 1: return mpc_pos(z, prec, rnd)
if n == 2: return mpc_mul(z, z, prec, rnd)
if n == -1: return mpc_div(mpc_one, z, prec, rnd)
if n < 0: return mpc_div(mpc_one, mpc_pow_int(z, -n, prec + 4), prec, rnd)
a, b = z
asign, aman, aexp, abc = a
bsign, bman, bexp, bbc = b
if asign: aman = -aman
if bsign: bman = -bman
de = aexp - bexp
abs_de = abs(de)
exact_size = n * (abs_de + max(abc, bbc))
if exact_size < 10000:
if de > 0:
aman <<= de
aexp = bexp
else:
bman <<= (-de)
bexp = aexp
re, im = complex_int_pow(aman, bman, n)
re = from_man_exp(re, int(n * aexp), prec, rnd)
im = from_man_exp(im, int(n * bexp), prec, rnd)
return re, im
return mpc_exp(mpc_mul_int(mpc_log(z, prec + 10), n, prec + 10), prec, rnd)
def mpc_ci_si_taylor(re, im, wp, which=0):
# The following code is only designed for small arguments,
# and not too small arguments (for relative accuracy)
if re[1]:
mag = re[2] + re[3]
elif im[1]:
mag = im[2] + im[3]
if im[1]:
mag = max(mag, im[2] + im[3])
if mag > 2 or mag < -wp:
raise NotImplementedError
wp += (2 - mag)
zre = to_fixed(re, wp)
zim = to_fixed(im, wp)
z2re = (zim * zim - zre * zre) >> wp
z2im = (-2 * zre * zim) >> wp
tre = zre
tim = zim
one = MPZ_ONE << wp
if which == 0:
sre, sim, tre, tim, k = 0, 0, (MPZ_ONE << wp), 0, 2
else:
sre, sim, tre, tim, k = zre, zim, zre, zim, 3
while max(abs(tre), abs(tim)) > 2:
f = k * (k - 1)
tre, tim = ((tre * z2re - tim * z2im) // f) >> wp, (
(tre * z2im + tim * z2re) // f) >> wp
sre += tre // k
sim += tim // k
k += 2
return from_man_exp(sre, -wp), from_man_exp(sim, -wp)
def mpc_zeta(s, prec, rnd):
re, im = s
wp = prec + 20
n = int(wp/2.54 + 5)
n += int(0.9*abs(to_int(im)))
d = borwein_coefficients(n)
ref = to_fixed(re, wp)
imf = to_fixed(im, wp)
tre = MP_ZERO
tim = MP_ZERO
one = MP_ONE << wp
one_2wp = MP_ONE << (2*wp)
critical_line = re == fhalf
for k in xrange(n):
log = log_int_fixed(k+1, wp)
# A square root is much cheaper than an exp
if critical_line:
w = one_2wp // sqrt_fixed((k+1) << wp, wp)
else:
w = to_fixed(mpf_exp(from_man_exp(-ref*log, -2*wp), wp), wp)
if k & 1:
w *= (d[n] - d[k])
else:
w *= (d[k] - d[n])
wre, wim = cos_sin(from_man_exp(-imf * log_int_fixed(k+1, wp), -2*wp), wp)
tre += (w * to_fixed(wre, wp)) >> wp
tim += (w * to_fixed(wim, wp)) >> wp
tre //= (-d[n])
tim //= (-d[n])
tre = from_man_exp(tre, -wp, wp)
tim = from_man_exp(tim, -wp, wp)
q = mpc_sub(mpc_one, mpc_pow(mpc_two, mpc_sub(mpc_one, s, wp), wp), wp)
return mpc_div((tre, tim), q, prec, rnd)
def mpc_zeta(s, prec, rnd=round_fast, alt=0):
re, im = s
if im == fzero:
return mpf_zeta(re, prec, rnd, alt), fzero
wp = prec + 20
# Reflection formula. To be rigorous, we should reflect to the left of
# re = 1/2 (see comments for mpf_zeta), but this leads to unnecessary
# slowdown for interesting values of s
if mpf_lt(re, fzero):
# XXX: could use the separate refl. formula for Dirichlet eta
if alt:
q = mpc_sub(mpc_one, mpc_pow(mpc_two, mpc_sub(mpc_one, s, wp),
wp), wp)
return mpc_mul(mpc_zeta(s, wp), q, prec, rnd)
# XXX: -1 should be done exactly
y = mpc_sub(mpc_one, s, 10*wp)
a = mpc_gamma(y, wp)
b = mpc_zeta(y, wp)
c = mpc_sin_pi(mpc_shift(s, -1), wp)
rsign, rman, rexp, rbc = re
isign, iman, iexp, ibc = im
mag = max(rexp+rbc, iexp+ibc)
wp2 = wp + mag
pi = mpf_pi(wp+wp2)
pi2 = (mpf_shift(pi, 1), fzero)
d = mpc_div_mpf(mpc_pow(pi2, s, wp2), pi, wp2)
return mpc_mul(a,mpc_mul(b,mpc_mul(c,d,wp),wp),prec,rnd)
n = int(wp/2.54 + 5)
n += int(0.9*abs(to_int(im)))
d = borwein_coefficients(n)
ref = to_fixed(re, wp)
imf = to_fixed(im, wp)
tre = MP_ZERO
tim = MP_ZERO
one = MP_ONE << wp
one_2wp = MP_ONE << (2*wp)
critical_line = re == fhalf
for k in xrange(n):
log = log_int_fixed(k+1, wp)
# A square root is much cheaper than an exp
if critical_line:
w = one_2wp // sqrt_fixed((k+1) << wp, wp)
else:
w = to_fixed(mpf_exp(from_man_exp(-ref*log, -2*wp), wp), wp)
if k & 1:
w *= (d[n] - d[k])
else:
w *= (d[k] - d[n])
wre, wim = cos_sin(from_man_exp(-imf * log_int_fixed(k+1, wp), -2*wp), wp)
tre += (w * to_fixed(wre, wp)) >> wp
tim += (w * to_fixed(wim, wp)) >> wp
tre //= (-d[n])
tim //= (-d[n])
tre = from_man_exp(tre, -wp, wp)
tim = from_man_exp(tim, -wp, wp)
if alt:
return mpc_pos((tre, tim), prec, rnd)
else:
q = mpc_sub(mpc_one, mpc_pow(mpc_two, mpc_sub(mpc_one, s, wp), wp), wp)
return mpc_div((tre, tim), q, prec, rnd)
def mpc_besseljn(n, z, prec):
negate = n < 0 and n & 1
n = abs(n)
origprec = prec
prec += 20 + bitcount(abs(n))
zre, zim = z
zre = to_fixed(zre, prec)
zim = to_fixed(zim, prec)
z2re = (zre**2 - zim**2) >> prec
z2im = (zre*zim) >> (prec-1)
if not n:
sre = tre = MP_ONE << prec
sim = tim = MP_ZERO
else:
re, im = complex_int_pow(zre, zim, n)
sre = tre = (re // int_fac(n)) >> ((n-1)*prec + n)
sim = tim = (im // int_fac(n)) >> ((n-1)*prec + n)
k = 1
while abs(tre) + abs(tim) > 3:
p = -4*k*(k+n)
tre, tim = tre*z2re - tim*z2im, tim*z2re + tre*z2im
tre = (tre // p) >> prec
tim = (tim // p) >> prec
sre += tre
sim += tim
k += 1
if negate:
sre = -sre
sim = -sim
re = from_man_exp(sre, -prec, origprec, round_nearest)
im = from_man_exp(sim, -prec, origprec, round_nearest)
return (re, im)
def mpc_besseljn(n, z, prec, rounding=round_fast):
negate = n < 0 and n & 1
n = abs(n)
origprec = prec
prec += 20 + bitcount(abs(n))
zre, zim = z
zre = to_fixed(zre, prec)
zim = to_fixed(zim, prec)
z2re = (zre**2 - zim**2) >> prec
z2im = (zre * zim) >> (prec - 1)
if not n:
sre = tre = MP_ONE << prec
sim = tim = MP_ZERO
else:
re, im = complex_int_pow(zre, zim, n)
sre = tre = (re // int_fac(n)) >> ((n - 1) * prec + n)
sim = tim = (im // int_fac(n)) >> ((n - 1) * prec + n)
k = 1
while abs(tre) + abs(tim) > 3:
p = -4 * k * (k + n)
tre, tim = tre * z2re - tim * z2im, tim * z2re + tre * z2im
tre = (tre // p) >> prec
tim = (tim // p) >> prec
sre += tre
sim += tim
k += 1
if negate:
sre = -sre
sim = -sim
re = from_man_exp(sre, -prec, origprec, rounding)
im = from_man_exp(sim, -prec, origprec, rounding)
return (re, im)
def mpf_psi0(x, prec, rnd=round_fast):
"""
Computation of the digamma function (psi function of order 0)
of a real argument.
"""
sign, man, exp, bc = x
wp = prec + 10
if not man:
if x == finf: return x
if x == fninf or x == fnan: return fnan
if x == fzero or (exp >= 0 and sign):
raise ValueError("polygamma pole")
# Reflection formula
if sign and exp + bc > 3:
c, s = mpf_cos_sin_pi(x, wp)
q = mpf_mul(mpf_div(c, s, wp), mpf_pi(wp), wp)
p = mpf_psi0(mpf_sub(fone, x, wp), wp)
return mpf_sub(p, q, prec, rnd)
# The logarithmic term is accurate enough
if (not sign) and bc + exp > wp:
return mpf_log(mpf_sub(x, fone, wp), prec, rnd)
# Initial recurrence to obtain a large enough x
m = to_int(x)
n = int(0.11 * wp) + 2
s = MP_ZERO
x = to_fixed(x, wp)
one = MP_ONE << wp
if m < n:
for k in xrange(m, n):
s -= (one << wp) // x
x += one
x -= one
# Logarithmic term
s += to_fixed(mpf_log(from_man_exp(x, -wp, wp), wp), wp)
# Endpoint term in Euler-Maclaurin expansion
s += (one << wp) // (2 * x)
# Euler-Maclaurin remainder sum
x2 = (x * x) >> wp
t = one
prev = 0
k = 1
while 1:
t = (t * x2) >> wp
bsign, bman, bexp, bbc = mpf_bernoulli(2 * k, wp)
offset = (bexp + 2 * wp)
if offset >= 0: term = (bman << offset) // (t * (2 * k))
else: term = (bman >> (-offset)) // (t * (2 * k))
if k & 1: s -= term
else: s += term
if k > 2 and term >= prev:
break
prev = term
k += 1
return from_man_exp(s, -wp, wp, rnd)
def mpf_zeta_int(s, prec, rnd=round_fast):
"""
Optimized computation of zeta(s) for an integer s.
"""
wp = prec + 20
s = int(s)
if s in zeta_int_cache and zeta_int_cache[s][0] >= wp:
return mpf_pos(zeta_int_cache[s][1], prec, rnd)
if s < 2:
if s == 1:
raise ValueError("zeta(1) pole")
if not s:
return mpf_neg(fhalf)
return mpf_div(mpf_bernoulli(-s + 1, wp), from_int(s - 1), prec, rnd)
# 2^-s term vanishes?
if s >= wp:
return mpf_perturb(fone, 0, prec, rnd)
# 5^-s term vanishes?
elif s >= wp * 0.431:
t = one = 1 << wp
t += 1 << (wp - s)
t += one // (MPZ_THREE**s)
t += 1 << max(0, wp - s * 2)
return from_man_exp(t, -wp, prec, rnd)
else:
# Fast enough to sum directly?
# Even better, we use the Euler product (idea stolen from pari)
m = (float(wp) / (s - 1) + 1)
if m < 30:
needed_terms = int(2.0**m + 1)
if needed_terms < int(wp / 2.54 + 5) / 10:
t = fone
for k in list_primes(needed_terms):
#print k, needed_terms
powprec = int(wp - s * math.log(k, 2))
if powprec < 2:
break
a = mpf_sub(fone, mpf_pow_int(from_int(k), -s, powprec),
wp)
t = mpf_mul(t, a, wp)
return mpf_div(fone, t, wp)
# Use Borwein's algorithm
n = int(wp / 2.54 + 5)
d = borwein_coefficients(n)
t = MPZ_ZERO
s = MPZ(s)
for k in xrange(n):
t += (((-1)**k * (d[k] - d[n])) << wp) // (k + 1)**s
t = (t << wp) // (-d[n])
t = (t << wp) // ((1 << wp) - (1 << (wp + 1 - s)))
if (s in zeta_int_cache
and zeta_int_cache[s][0] < wp) or (s not in zeta_int_cache):
zeta_int_cache[s] = (wp, from_man_exp(t, -wp - wp))
return from_man_exp(t, -wp - wp, prec, rnd)
def mpi_cos_sin(x, prec):
a, b = x
if a == b == fzero:
return (fone, fone), (fzero, fzero)
# Guaranteed to contain both -1 and 1
if (finf in x) or (fninf in x):
return (fnone, fone), (fnone, fone)
wp = prec + 20
ca, sa, na = cos_sin_quadrant(a, wp)
cb, sb, nb = cos_sin_quadrant(b, wp)
ca, cb = mpf_min_max([ca, cb])
sa, sb = mpf_min_max([sa, sb])
# Both functions are monotonic within one quadrant
if na == nb:
pass
# Guaranteed to contain both -1 and 1
elif nb - na >= 4:
return (fnone, fone), (fnone, fone)
else:
# cos has maximum between a and b
if na // 4 != nb // 4:
cb = fone
# cos has minimum
if (na - 2) // 4 != (nb - 2) // 4:
ca = fnone
# sin has maximum
if (na - 1) // 4 != (nb - 1) // 4:
sb = fone
# sin has minimum
if (na - 3) // 4 != (nb - 3) // 4:
sa = fnone
# Perturb to force interval rounding
more = from_man_exp((MPZ_ONE << wp) + (MPZ_ONE << 10), -wp)
less = from_man_exp((MPZ_ONE << wp) - (MPZ_ONE << 10), -wp)
def finalize(v, rounding):
if bool(v[0]) == (rounding == round_floor):
p = more
else:
p = less
v = mpf_mul(v, p, prec, rounding)
sign, man, exp, bc = v
if exp + bc >= 1:
if sign:
return fnone
return fone
return v
ca = finalize(ca, round_floor)
cb = finalize(cb, round_ceiling)
sa = finalize(sa, round_floor)
sb = finalize(sb, round_ceiling)
return (ca, cb), (sa, sb)
def spouge_sum_complex(re, im, prec, a, c):
re = to_fixed(re, prec)
im = to_fixed(im, prec)
sre, sim = c[0], 0
mag = ((re**2) >> prec) + ((im**2) >> prec)
for k in xrange(1, a):
M = mag + re * (2 * k) + ((k**2) << prec)
sre += (c[k] * (re + (k << prec))) // M
sim -= (c[k] * im) // M
re = from_man_exp(sre, -prec, prec, round_floor)
im = from_man_exp(sim, -prec, prec, round_floor)
return re, im
def spouge_sum_complex(re, im, prec, a, c):
re = to_fixed(re, prec)
im = to_fixed(im, prec)
sre, sim = c[0], 0
mag = ((re**2)>>prec) + ((im**2)>>prec)
for k in xrange(1, a):
M = mag + re*(2*k) + ((k**2) << prec)
sre += (c[k] * (re + (k << prec))) // M
sim -= (c[k] * im) // M
re = from_man_exp(sre, -prec, prec, round_floor)
im = from_man_exp(sim, -prec, prec, round_floor)
return re, im
def mpf_zeta_int(s, prec, rnd=round_fast):
"""
Optimized computation of zeta(s) for an integer s.
"""
wp = prec + 20
s = int(s)
if s in zeta_int_cache and zeta_int_cache[s][0] >= wp:
return mpf_pos(zeta_int_cache[s][1], prec, rnd)
if s < 2:
if s == 1:
raise ValueError("zeta(1) pole")
if not s:
return mpf_neg(fhalf)
return mpf_div(mpf_bernoulli(-s+1, wp), from_int(s-1), prec, rnd)
# 2^-s term vanishes?
if s >= wp:
return mpf_perturb(fone, 0, prec, rnd)
# 5^-s term vanishes?
elif s >= wp*0.431:
t = one = 1 << wp
t += 1 << (wp - s)
t += one // (MPZ_THREE ** s)
t += 1 << max(0, wp - s*2)
return from_man_exp(t, -wp, prec, rnd)
else:
# Fast enough to sum directly?
# Even better, we use the Euler product (idea stolen from pari)
m = (float(wp)/(s-1) + 1)
if m < 30:
needed_terms = int(2.0**m + 1)
if needed_terms < int(wp/2.54 + 5) / 10:
t = fone
for k in list_primes(needed_terms):
#print k, needed_terms
powprec = int(wp - s*math.log(k,2))
if powprec < 2:
break
a = mpf_sub(fone, mpf_pow_int(from_int(k), -s, powprec), wp)
t = mpf_mul(t, a, wp)
return mpf_div(fone, t, wp)
# Use Borwein's algorithm
n = int(wp/2.54 + 5)
d = borwein_coefficients(n)
t = MPZ_ZERO
s = MPZ(s)
for k in xrange(n):
t += (((-1)**k * (d[k] - d[n])) << wp) // (k+1)**s
t = (t << wp) // (-d[n])
t = (t << wp) // ((1 << wp) - (1 << (wp+1-s)))
if (s in zeta_int_cache and zeta_int_cache[s][0] < wp) or (s not in zeta_int_cache):
zeta_int_cache[s] = (wp, from_man_exp(t, -wp-wp))
return from_man_exp(t, -wp-wp, prec, rnd)
def glaisher_fixed(prec):
wp = prec + 30
# Number of direct terms to sum before applying the Euler-Maclaurin
# formula to the tail. TODO: choose more intelligently
N = int(0.33 * prec + 5)
ONE = MP_ONE << wp
# Euler-Maclaurin, step 1: sum log(k)/k**2 for k from 2 to N-1
s = MP_ZERO
for k in range(2, N):
#print k, N
s += log_int_fixed(k, wp) // k**2
logN = log_int_fixed(N, wp)
#logN = to_fixed(mpf_log(from_int(N), wp+20), wp)
# E-M step 2: integral of log(x)/x**2 from N to inf
s += (ONE + logN) // N
# E-M step 3: endpoint correction term f(N)/2
s += logN // (N**2 * 2)
# E-M step 4: the series of derivatives
pN = N**3
a = 1
b = -2
j = 3
fac = from_int(2)
k = 1
while 1:
# D(2*k-1) * B(2*k) / fac(2*k) [D(n) = nth derivative]
D = ((a << wp) + b * logN) // pN
D = from_man_exp(D, -wp)
B = mpf_bernoulli(2 * k, wp)
term = mpf_mul(B, D, wp)
term = mpf_div(term, fac, wp)
term = to_fixed(term, wp)
if abs(term) < 100:
break
#if not k % 10:
# print k, math.log(int(abs(term)), 10)
s -= term
# Advance derivative twice
a, b, pN, j = b - a * j, -j * b, pN * N, j + 1
a, b, pN, j = b - a * j, -j * b, pN * N, j + 1
k += 1
fac = mpf_mul_int(fac, (2 * k) * (2 * k - 1), wp)
# A = exp((6*s/pi**2 + log(2*pi) + euler)/12)
pi = pi_fixed(wp)
s *= 6
s = (s << wp) // (pi**2 >> wp)
s += euler_fixed(wp)
s += to_fixed(mpf_log(from_man_exp(2 * pi, -wp), wp), wp)
s //= 12
A = mpf_exp(from_man_exp(s, -wp), wp)
return to_fixed(A, prec)
def mpi_cos_sin(x, prec):
a, b = x
if a == b == fzero:
return (fone, fone), (fzero, fzero)
# Guaranteed to contain both -1 and 1
if (finf in x) or (fninf in x):
return (fnone, fone), (fnone, fone)
wp = prec + 20
ca, sa, na = cos_sin_quadrant(a, wp)
cb, sb, nb = cos_sin_quadrant(b, wp)
ca, cb = mpf_min_max([ca, cb])
sa, sb = mpf_min_max([sa, sb])
# Both functions are monotonic within one quadrant
if na == nb:
pass
# Guaranteed to contain both -1 and 1
elif nb - na >= 4:
return (fnone, fone), (fnone, fone)
else:
# cos has maximum between a and b
if na//4 != nb//4:
cb = fone
# cos has minimum
if (na-2)//4 != (nb-2)//4:
ca = fnone
# sin has maximum
if (na-1)//4 != (nb-1)//4:
sb = fone
# sin has minimum
if (na-3)//4 != (nb-3)//4:
sa = fnone
# Perturb to force interval rounding
more = from_man_exp((MPZ_ONE<<wp) + (MPZ_ONE<<10), -wp)
less = from_man_exp((MPZ_ONE<<wp) - (MPZ_ONE<<10), -wp)
def finalize(v, rounding):
if bool(v[0]) == (rounding == round_floor):
p = more
else:
p = less
v = mpf_mul(v, p, prec, rounding)
sign, man, exp, bc = v
if exp+bc >= 1:
if sign:
return fnone
return fone
return v
ca = finalize(ca, round_floor)
cb = finalize(cb, round_ceiling)
sa = finalize(sa, round_floor)
sb = finalize(sb, round_ceiling)
return (ca,cb), (sa,sb)
def glaisher_fixed(prec):
wp = prec + 30
# Number of direct terms to sum before applying the Euler-Maclaurin
# formula to the tail. TODO: choose more intelligently
N = int(0.33*prec + 5)
ONE = MPZ_ONE << wp
# Euler-Maclaurin, step 1: sum log(k)/k**2 for k from 2 to N-1
s = MPZ_ZERO
for k in range(2, N):
#print k, N
s += log_int_fixed(k, wp) // k**2
logN = log_int_fixed(N, wp)
#logN = to_fixed(mpf_log(from_int(N), wp+20), wp)
# E-M step 2: integral of log(x)/x**2 from N to inf
s += (ONE + logN) // N
# E-M step 3: endpoint correction term f(N)/2
s += logN // (N**2 * 2)
# E-M step 4: the series of derivatives
pN = N**3
a = 1
b = -2
j = 3
fac = from_int(2)
k = 1
while 1:
# D(2*k-1) * B(2*k) / fac(2*k) [D(n) = nth derivative]
D = ((a << wp) + b*logN) // pN
D = from_man_exp(D, -wp)
B = mpf_bernoulli(2*k, wp)
term = mpf_mul(B, D, wp)
term = mpf_div(term, fac, wp)
term = to_fixed(term, wp)
if abs(term) < 100:
break
#if not k % 10:
# print k, math.log(int(abs(term)), 10)
s -= term
# Advance derivative twice
a, b, pN, j = b-a*j, -j*b, pN*N, j+1
a, b, pN, j = b-a*j, -j*b, pN*N, j+1
k += 1
fac = mpf_mul_int(fac, (2*k)*(2*k-1), wp)
# A = exp((6*s/pi**2 + log(2*pi) + euler)/12)
pi = pi_fixed(wp)
s *= 6
s = (s << wp) // (pi**2 >> wp)
s += euler_fixed(wp)
s += to_fixed(mpf_log(from_man_exp(2*pi, -wp), wp), wp)
s //= 12
A = mpf_exp(from_man_exp(s, -wp), wp)
return to_fixed(A, prec)
def mpf_zeta(s, prec, rnd=round_fast):
sign, man, exp, bc = s
if not man:
if s == fzero:
return mpf_neg(fhalf)
if s == finf:
return fone
return fnan
wp = prec + 20
# First term vanishes?
if (not sign) and (exp + bc > (math.log(wp,2) + 2)):
if rnd in (round_up, round_ceiling):
return mpf_add(fone, mpf_shift(fone,-wp-10), prec, rnd)
return fone
elif exp >= 0:
return mpf_zeta_int(to_int(s), prec, rnd)
# Less than 0.5?
if sign or (exp+bc) < 0:
# XXX: -1 should be done exactly
y = mpf_sub(fone, s, 10*wp)
a = mpf_gamma(y, wp)
b = mpf_zeta(y, wp)
c = mpf_sin_pi(mpf_shift(s, -1), wp)
wp2 = wp + (exp+bc)
pi = mpf_pi(wp+wp2)
d = mpf_div(mpf_pow(mpf_shift(pi, 1), s, wp2), pi, wp2)
return mpf_mul(a,mpf_mul(b,mpf_mul(c,d,wp),wp),prec,rnd)
t = MP_ZERO
#wp += 16 - (prec & 15)
# Use Borwein's algorithm
n = int(wp/2.54 + 5)
d = borwein_coefficients(n)
t = MP_ZERO
sf = to_fixed(s, wp)
for k in xrange(n):
u = from_man_exp(-sf*log_int_fixed(k+1, wp), -2*wp, wp)
esign, eman, eexp, ebc = mpf_exp(u, wp)
offset = eexp + wp
if offset >= 0:
w = ((d[k] - d[n]) * eman) << offset
else:
w = ((d[k] - d[n]) * eman) >> (-offset)
if k & 1:
t -= w
else:
t += w
t = t // (-d[n])
t = from_man_exp(t, -wp, wp)
q = mpf_sub(fone, mpf_pow(ftwo, mpf_sub(fone, s, wp), wp), wp)
return mpf_div(t, q, prec, rnd)
def mpf_zeta(s, prec, rnd=round_fast):
sign, man, exp, bc = s
if not man:
if s == fzero:
return mpf_neg(fhalf)
if s == finf:
return fone
return fnan
wp = prec + 20
# First term vanishes?
if (not sign) and (exp + bc > (math.log(wp, 2) + 2)):
if rnd in (round_up, round_ceiling):
return mpf_add(fone, mpf_shift(fone, -wp - 10), prec, rnd)
return fone
elif exp >= 0:
return mpf_zeta_int(to_int(s), prec, rnd)
# Less than 0.5?
if sign or (exp + bc) < 0:
# XXX: -1 should be done exactly
y = mpf_sub(fone, s, 10 * wp)
a = mpf_gamma(y, wp)
b = mpf_zeta(y, wp)
c = mpf_sin_pi(mpf_shift(s, -1), wp)
wp2 = wp + (exp + bc)
pi = mpf_pi(wp + wp2)
d = mpf_div(mpf_pow(mpf_shift(pi, 1), s, wp2), pi, wp2)
return mpf_mul(a, mpf_mul(b, mpf_mul(c, d, wp), wp), prec, rnd)
t = MP_ZERO
#wp += 16 - (prec & 15)
# Use Borwein's algorithm
n = int(wp / 2.54 + 5)
d = borwein_coefficients(n)
t = MP_ZERO
sf = to_fixed(s, wp)
for k in xrange(n):
u = from_man_exp(-sf * log_int_fixed(k + 1, wp), -2 * wp, wp)
esign, eman, eexp, ebc = mpf_exp(u, wp)
offset = eexp + wp
if offset >= 0:
w = ((d[k] - d[n]) * eman) << offset
else:
w = ((d[k] - d[n]) * eman) >> (-offset)
if k & 1:
t -= w
else:
t += w
t = t // (-d[n])
t = from_man_exp(t, -wp, wp)
q = mpf_sub(fone, mpf_pow(ftwo, mpf_sub(fone, s, wp), wp), wp)
return mpf_div(t, q, prec, rnd)
def mpf_cos_sin_pi(x, prec, rnd=round_fast):
"""Accurate computation of (cos(pi*x), sin(pi*x))
for x close to an integer"""
sign, man, exp, bc = x
if not man:
return cos_sin(x, prec, rnd)
# Exactly an integer or half-integer?
if exp >= -1:
if exp == -1:
c = fzero
s = (fone, fnone)[bool(man & 2) ^ sign]
elif exp == 0:
c, s = (fnone, fzero)
else:
c, s = (fone, fzero)
return c, s
# Close to 0 ?
size = exp + bc
if size < -(prec + 5):
return (fone, mpf_mul(x, mpf_pi(wp), prec, rnd))
if sign:
man = -man
# Subtract nearest integer (= modulo pi)
nint = ((man >> (-exp - 1)) + 1) >> 1
man = man - (nint << (-exp))
x = from_man_exp(man, exp, prec)
x = mpf_mul(x, mpf_pi(prec), prec)
# Shifted an odd multiple of pi ?
if nint & 1:
c, s = cos_sin(x, prec, negative_rnd[rnd])
return mpf_neg(c), mpf_neg(s)
else:
return cos_sin(x, prec, rnd)
def khinchin_fixed(prec):
wp = int(prec + prec**0.5 + 15)
s = MP_ZERO
fac = from_int(4)
t = ONE = MP_ONE << wp
pi = mpf_pi(wp)
pipow = twopi2 = mpf_shift(mpf_mul(pi, pi, wp), 2)
n = 1
while 1:
zeta2n = mpf_abs(mpf_bernoulli(2 * n, wp))
zeta2n = mpf_mul(zeta2n, pipow, wp)
zeta2n = mpf_div(zeta2n, fac, wp)
zeta2n = to_fixed(zeta2n, wp)
term = (((zeta2n - ONE) * t) // n) >> wp
if term < 100:
break
#if not n % 100:
# print n, nstr(ln(term))
s += term
t += ONE // (2 * n + 1) - ONE // (2 * n)
n += 1
fac = mpf_mul_int(fac, (2 * n) * (2 * n - 1), wp)
pipow = mpf_mul(pipow, twopi2, wp)
s = (s << wp) // ln2_fixed(wp)
K = mpf_exp(from_man_exp(s, -wp), wp)
K = to_fixed(K, prec)
return K
def mpf_cos_sin_pi(x, prec, rnd=round_fast):
"""Accurate computation of (cos(pi*x), sin(pi*x))
for x close to an integer"""
sign, man, exp, bc = x
if not man:
return cos_sin(x, prec, rnd)
# Exactly an integer or half-integer?
if exp >= -1:
if exp == -1:
c = fzero
s = (fone, fnone)[bool(man & 2) ^ sign]
elif exp == 0:
c, s = (fnone, fzero)
else:
c, s = (fone, fzero)
return c, s
# Close to 0 ?
size = exp + bc
if size < -(prec+5):
return (fone, mpf_mul(x, mpf_pi(wp), prec, rnd))
if sign:
man = -man
# Subtract nearest integer (= modulo pi)
nint = ((man >> (-exp-1)) + 1) >> 1
man = man - (nint << (-exp))
x = from_man_exp(man, exp, prec)
x = mpf_mul(x, mpf_pi(prec), prec)
# Shifted an odd multiple of pi ?
if nint & 1:
c, s = cos_sin(x, prec, negative_rnd[rnd])
return mpf_neg(c), mpf_neg(s)
else:
return cos_sin(x, prec, rnd)
def khinchin_fixed(prec):
wp = int(prec + prec**0.5 + 15)
s = MPZ_ZERO
fac = from_int(4)
t = ONE = MPZ_ONE << wp
pi = mpf_pi(wp)
pipow = twopi2 = mpf_shift(mpf_mul(pi, pi, wp), 2)
n = 1
while 1:
zeta2n = mpf_abs(mpf_bernoulli(2*n, wp))
zeta2n = mpf_mul(zeta2n, pipow, wp)
zeta2n = mpf_div(zeta2n, fac, wp)
zeta2n = to_fixed(zeta2n, wp)
term = (((zeta2n - ONE) * t) // n) >> wp
if term < 100:
break
#if not n % 10:
# print n, math.log(int(abs(term)))
s += term
t += ONE//(2*n+1) - ONE//(2*n)
n += 1
fac = mpf_mul_int(fac, (2*n)*(2*n-1), wp)
pipow = mpf_mul(pipow, twopi2, wp)
s = (s << wp) // ln2_fixed(wp)
K = mpf_exp(from_man_exp(s, -wp), wp)
K = to_fixed(K, prec)
return K
def mpf_atan(x, prec, rnd=round_fast):
sign, man, exp, bc = x
if not man:
if x == fzero: return fzero
if x == finf: return atan_inf(0, prec, rnd)
if x == fninf: return atan_inf(1, prec, rnd)
return fnan
mag = exp + bc
# Essentially infinity
if mag > prec+20:
return atan_inf(sign, prec, rnd)
# Essentially ~ x
if -mag > prec+20:
return mpf_perturb(x, 1-sign, prec, rnd)
wp = prec + 30 + abs(mag)
# For large x, use atan(x) = pi/2 - atan(1/x)
if mag >= 2:
x = mpf_rdiv_int(1, x, wp)
reciprocal = True
else:
reciprocal = False
t = to_fixed(x, wp)
if sign:
t = -t
if wp < ATAN_TAYLOR_PREC:
a = atan_taylor(t, wp)
else:
a = atan_newton(t, wp)
if reciprocal:
a = ((pi_fixed(wp)>>1)+1) - a
if sign:
a = -a
return from_man_exp(a, -wp, prec, rnd)
def mpf_atan(x, prec, rnd=round_fast):
sign, man, exp, bc = x
if not man:
if x == fzero: return fzero
if x == finf: return atan_inf(0, prec, rnd)
if x == fninf: return atan_inf(1, prec, rnd)
return fnan
mag = exp + bc
# Essentially infinity
if mag > prec+20:
return atan_inf(sign, prec, rnd)
# Essentially ~ x
if -mag > prec+20:
return mpf_perturb(x, 1-sign, prec, rnd)
wp = prec + 30 + abs(mag)
# For large x, use atan(x) = pi/2 - atan(1/x)
if mag >= 2:
x = mpf_rdiv_int(1, x, wp)
reciprocal = True
else:
reciprocal = False
t = to_fixed(x, wp)
if sign:
t = -t
if wp < ATAN_TAYLOR_PREC:
a = atan_taylor(t, wp)
else:
a = atan_newton(t, wp)
if reciprocal:
a = ((pi_fixed(wp)>>1)+1) - a
if sign:
a = -a
return from_man_exp(a, -wp, prec, rnd)
def exp_fixed_prod(x, wp):
u = from_man_exp(x, -2*wp, wp)
esign, eman, eexp, ebc = mpf_exp(u, wp)
offset = eexp + wp
if offset >= 0:
return eman << offset
else:
return eman >> (-offset)
def exp_fixed_prod(x, wp):
u = from_man_exp(x, -2 * wp, wp)
esign, eman, eexp, ebc = mpf_exp(u, wp)
offset = eexp + wp
if offset >= 0:
return eman << offset
else:
return eman >> (-offset)
def mpc_pow_int(z, n, prec, rnd=round_fast):
a, b = z
if b == fzero:
return mpf_pow_int(a, n, prec, rnd), fzero
if a == fzero:
v = mpf_pow_int(b, n, prec, rnd)
n %= 4
if n == 0:
return v, fzero
elif n == 1:
return fzero, v
elif n == 2:
return mpf_neg(v), fzero
elif n == 3:
return fzero, mpf_neg(v)
if n == 0:
return mpc_one
if n == 1:
return mpc_pos(z, prec, rnd)
if n == 2:
return mpc_square(z, prec, rnd)
if n == -1:
return mpc_reciprocal(z, prec, rnd)
if n < 0:
return mpc_reciprocal(mpc_pow_int(z, -n, prec + 4), prec, rnd)
asign, aman, aexp, abc = a
bsign, bman, bexp, bbc = b
if asign:
aman = -aman
if bsign:
bman = -bman
de = aexp - bexp
abs_de = abs(de)
exact_size = n * (abs_de + max(abc, bbc))
if exact_size < 10000:
if de > 0:
aman <<= de
aexp = bexp
else:
bman <<= -de
bexp = aexp
re, im = complex_int_pow(aman, bman, n)
re = from_man_exp(re, int(n * aexp), prec, rnd)
im = from_man_exp(im, int(n * bexp), prec, rnd)
return re, im
return mpc_exp(mpc_mul_int(mpc_log(z, prec + 10), n, prec + 10), prec, rnd)
def mpf_agm(a, b, prec, rnd=round_fast):
"""
Computes the arithmetic-geometric mean agm(a,b) for
nonnegative mpf values a, b.
"""
asign, aman, aexp, abc = a
bsign, bman, bexp, bbc = b
if asign or bsign:
raise ComplexResult("agm of a negative number")
# Handle inf, nan or zero in either operand
if not (aman and bman):
if a == fnan or b == fnan:
return fnan
if a == finf:
if b == fzero:
return fnan
return finf
if b == finf:
if a == fzero:
return fnan
return finf
# agm(0,x) = agm(x,0) = 0
return fzero
wp = prec + 20
amag = aexp+abc
bmag = bexp+bbc
mag_delta = amag - bmag
# Reduce to roughly the same magnitude using floating-point AGM
abs_mag_delta = abs(mag_delta)
if abs_mag_delta > 10:
while abs_mag_delta > 10:
a, b = mpf_shift(mpf_add(a,b,wp),-1), \
mpf_sqrt(mpf_mul(a,b,wp),wp)
abs_mag_delta //= 2
asign, aman, aexp, abc = a
bsign, bman, bexp, bbc = b
amag = aexp+abc
bmag = bexp+bbc
mag_delta = amag - bmag
#print to_float(a), to_float(b)
# Use agm(a,b) = agm(x*a,x*b)/x to obtain a, b ~= 1
min_mag = min(amag,bmag)
max_mag = max(amag,bmag)
n = 0
# If too small, we lose precision when going to fixed-point
if min_mag < -8:
n = -min_mag
# If too large, we waste time using fixed-point with large numbers
elif max_mag > 20:
n = -max_mag
if n:
a = mpf_shift(a, n)
b = mpf_shift(b, n)
#print to_float(a), to_float(b)
af = to_fixed(a, wp)
bf = to_fixed(b, wp)
g = agm_fixed(af, bf, wp)
return from_man_exp(g, -wp-n, prec, rnd)
def mpf_agm(a, b, prec, rnd=round_fast):
"""
Computes the arithmetic-geometric mean agm(a,b) for
nonnegative mpf values a, b.
"""
asign, aman, aexp, abc = a
bsign, bman, bexp, bbc = b
if asign or bsign:
raise ComplexResult("agm of a negative number")
# Handle inf, nan or zero in either operand
if not (aman and bman):
if a == fnan or b == fnan:
return fnan
if a == finf:
if b == fzero:
return fnan
return finf
if b == finf:
if a == fzero:
return fnan
return finf
# agm(0,x) = agm(x,0) = 0
return fzero
wp = prec + 20
amag = aexp + abc
bmag = bexp + bbc
mag_delta = amag - bmag
# Reduce to roughly the same magnitude using floating-point AGM
abs_mag_delta = abs(mag_delta)
if abs_mag_delta > 10:
while abs_mag_delta > 10:
a, b = mpf_shift(mpf_add(a,b,wp),-1), \
mpf_sqrt(mpf_mul(a,b,wp),wp)
abs_mag_delta //= 2
asign, aman, aexp, abc = a
bsign, bman, bexp, bbc = b
amag = aexp + abc
bmag = bexp + bbc
mag_delta = amag - bmag
#print to_float(a), to_float(b)
# Use agm(a,b) = agm(x*a,x*b)/x to obtain a, b ~= 1
min_mag = min(amag, bmag)
max_mag = max(amag, bmag)
n = 0
# If too small, we lose precision when going to fixed-point
if min_mag < -8:
n = -min_mag
# If too large, we waste time using fixed-point with large numbers
elif max_mag > 20:
n = -max_mag
if n:
a = mpf_shift(a, n)
b = mpf_shift(b, n)
#print to_float(a), to_float(b)
af = to_fixed(a, wp)
bf = to_fixed(b, wp)
g = agm_fixed(af, bf, wp)
return from_man_exp(g, -wp - n, prec, rnd)
def mpc_ci_si_taylor(re, im, wp, which=0):
zre = to_fixed(re, wp)
zim = to_fixed(im, wp)
z2re = (zim*zim-zre*zre)>>wp
z2im = (-2*zre*zim)>>wp
tre = zre
tim = zim
one = MP_ONE<<wp
if which == 0:
sre, sim, tre, tim, k = 0, 0, (MP_ONE<<wp), 0, 2
else:
sre, sim, tre, tim, k = zre, zim, zre, zim, 3
while max(abs(tre), abs(tim)) > 2:
f = k*(k-1)
tre, tim = ((tre*z2re-tim*z2im)//f)>>wp, ((tre*z2im+tim*z2re)//f)>>wp
sre += tre//k
sim += tim//k
k += 2
return from_man_exp(sre, -wp), from_man_exp(sim, -wp)
def mpc_ci_si_taylor(re, im, wp, which=0):
zre = to_fixed(re, wp)
zim = to_fixed(im, wp)
z2re = (zim * zim - zre * zre) >> wp
z2im = (-2 * zre * zim) >> wp
tre = zre
tim = zim
one = MP_ONE << wp
if which == 0:
sre, sim, tre, tim, k = 0, 0, (MP_ONE << wp), 0, 2
else:
sre, sim, tre, tim, k = zre, zim, zre, zim, 3
while max(abs(tre), abs(tim)) > 2:
f = k * (k - 1)
tre, tim = ((tre * z2re - tim * z2im) // f) >> wp, (
(tre * z2im + tim * z2re) // f) >> wp
sre += tre // k
sim += tim // k
k += 2
return from_man_exp(sre, -wp), from_man_exp(sim, -wp)
def mpf_ei(x, prec, rnd=round_fast, e1=False):
if e1:
x = mpf_neg(x)
sign, man, exp, bc = x
if e1 and not sign:
if x == fzero:
return finf
raise ComplexResult("E1(x) for x < 0")
if man:
xabs = 0, man, exp, bc
xmag = exp+bc
wp = prec + 20
can_use_asymp = xmag > wp
if not can_use_asymp:
if exp >= 0:
xabsint = man << exp
else:
xabsint = man >> (-exp)
can_use_asymp = xabsint > int(wp*0.693) + 10
if can_use_asymp:
if xmag > wp:
v = fone
else:
v = from_man_exp(ei_asymptotic(to_fixed(x, wp), wp), -wp)
v = mpf_mul(v, mpf_exp(x, wp), wp)
v = mpf_div(v, x, prec, rnd)
else:
wp += 2*int(to_int(xabs))
u = to_fixed(x, wp)
v = ei_taylor(u, wp) + euler_fixed(wp)
t1 = from_man_exp(v,-wp)
t2 = mpf_log(xabs,wp)
v = mpf_add(t1, t2, prec, rnd)
else:
if x == fzero: v = fninf
elif x == finf: v = finf
elif x == fninf: v = fzero
else: v = fnan
if e1:
v = mpf_neg(v)
return v
def mpf_ei(x, prec, rnd=round_fast, e1=False):
if e1:
x = mpf_neg(x)
sign, man, exp, bc = x
if e1 and not sign:
if x == fzero:
return finf
raise ComplexResult("E1(x) for x < 0")
if man:
xabs = 0, man, exp, bc
xmag = exp + bc
wp = prec + 20
can_use_asymp = xmag > wp
if not can_use_asymp:
if exp >= 0:
xabsint = man << exp
else:
xabsint = man >> (-exp)
can_use_asymp = xabsint > int(wp * 0.693) + 10
if can_use_asymp:
if xmag > wp:
v = fone
else:
v = from_man_exp(ei_asymptotic(to_fixed(x, wp), wp), -wp)
v = mpf_mul(v, mpf_exp(x, wp), wp)
v = mpf_div(v, x, prec, rnd)
else:
wp += 2 * int(to_int(xabs))
u = to_fixed(x, wp)
v = ei_taylor(u, wp) + euler_fixed(wp)
t1 = from_man_exp(v, -wp)
t2 = mpf_log(xabs, wp)
v = mpf_add(t1, t2, prec, rnd)
else:
if x == fzero: v = fninf
elif x == finf: v = finf
elif x == fninf: v = fzero
else: v = fnan
if e1:
v = mpf_neg(v)
return v
def mpc_nthroot(z, n, prec, rnd=round_fast):
"""
Complex n-th root.
Use Newton method as in the real case when it is faster,
otherwise use z**(1/n)
"""
a, b = z
if a[0] == 0 and b == fzero:
re = mpf_nthroot(a, n, prec, rnd)
return (re, fzero)
if n < 2:
if n == 0:
return mpc_one
if n == 1:
return mpc_pos((a, b), prec, rnd)
if n == -1:
return mpc_div(mpc_one, (a, b), prec, rnd)
inverse = mpc_nthroot((a, b), -n, prec+5, reciprocal_rnd[rnd])
return mpc_div(mpc_one, inverse, prec, rnd)
if n <= 20:
prec2 = int(1.2 * (prec + 10))
asign, aman, aexp, abc = a
bsign, bman, bexp, bbc = b
pf = mpc_abs((a,b), prec)
if pf[-2] + pf[-1] > -10 and pf[-2] + pf[-1] < prec:
af = to_fixed(a, prec2)
bf = to_fixed(b, prec2)
re, im = mpc_nthroot_fixed(af, bf, n, prec2)
extra = 10
re = from_man_exp(re, -prec2-extra, prec2, rnd)
im = from_man_exp(im, -prec2-extra, prec2, rnd)
return re, im
fn = from_int(n)
prec2 = prec+10 + 10
nth = mpf_rdiv_int(1, fn, prec2)
re, im = mpc_pow((a, b), (nth, fzero), prec2, rnd)
re = normalize(re[0], re[1], re[2], re[3], prec, rnd)
im = normalize(im[0], im[1], im[2], im[3], prec, rnd)
return re, im
def mpc_nthroot(z, n, prec, rnd=round_fast):
"""
Complex n-th root.
Use Newton method as in the real case when it is faster,
otherwise use z**(1/n)
"""
a, b = z
if a[0] == 0 and b == fzero:
re = mpf_nthroot(a, n, prec, rnd)
return (re, fzero)
if n < 2:
if n == 0:
return mpc_one
if n == 1:
return mpc_pos((a, b), prec, rnd)
if n == -1:
return mpc_div(mpc_one, (a, b), prec, rnd)
inverse = mpc_nthroot((a, b), -n, prec + 5, reciprocal_rnd[rnd])
return mpc_div(mpc_one, inverse, prec, rnd)
if n <= 20:
prec2 = int(1.2 * (prec + 10))
asign, aman, aexp, abc = a
bsign, bman, bexp, bbc = b
pf = mpc_abs((a, b), prec)
if pf[-2] + pf[-1] > -10 and pf[-2] + pf[-1] < prec:
af = to_fixed(a, prec2)
bf = to_fixed(b, prec2)
re, im = mpc_nthroot_fixed(af, bf, n, prec2)
extra = 10
re = from_man_exp(re, -prec2 - extra, prec2, rnd)
im = from_man_exp(im, -prec2 - extra, prec2, rnd)
return re, im
fn = from_int(n)
prec2 = prec + 10 + 10
nth = mpf_rdiv_int(1, fn, prec2)
re, im = mpc_pow((a, b), (nth, fzero), prec2, rnd)
re = normalize(re[0], re[1], re[2], re[3], prec, rnd)
im = normalize(im[0], im[1], im[2], im[3], prec, rnd)
return re, im
def mpc_pow_int(z, n, prec, rnd=round_fast):
a, b = z
if b == fzero:
return mpf_pow_int(a, n, prec, rnd), fzero
if a == fzero:
v = mpf_pow_int(b, n, prec, rnd)
n %= 4
if n == 0:
return v, fzero
elif n == 1:
return fzero, v
elif n == 2:
return mpf_neg(v), fzero
elif n == 3:
return fzero, mpf_neg(v)
if n == 0: return mpc_one
if n == 1: return mpc_pos(z, prec, rnd)
if n == 2: return mpc_square(z, prec, rnd)
if n == -1: return mpc_reciprocal(z, prec, rnd)
if n < 0: return mpc_reciprocal(mpc_pow_int(z, -n, prec+4), prec, rnd)
asign, aman, aexp, abc = a
bsign, bman, bexp, bbc = b
if asign: aman = -aman
if bsign: bman = -bman
de = aexp - bexp
abs_de = abs(de)
exact_size = n*(abs_de + max(abc, bbc))
if exact_size < 10000:
if de > 0:
aman <<= de
aexp = bexp
else:
bman <<= (-de)
bexp = aexp
re, im = complex_int_pow(aman, bman, n)
re = from_man_exp(re, int(n*aexp), prec, rnd)
im = from_man_exp(im, int(n*bexp), prec, rnd)
return re, im
return mpc_exp(mpc_mul_int(mpc_log(z, prec+10), n, prec+10), prec, rnd)
def mpf_ci_si_taylor(x, wp, which=0):
"""
0 - Ci(x) - (euler+log(x))
1 - Si(x)
"""
x = to_fixed(x, wp)
x2 = -(x * x) >> wp
if which == 0:
s, t, k = 0, (MP_ONE << wp), 2
else:
s, t, k = x, x, 3
while t:
t = (t * x2 // (k * (k - 1))) >> wp
s += t // k
k += 2
return from_man_exp(s, -wp)
def mpf_ci_si_taylor(x, wp, which=0):
"""
0 - Ci(x) - (euler+log(x))
1 - Si(x)
"""
x = to_fixed(x, wp)
x2 = -(x*x) >> wp
if which == 0:
s, t, k = 0, (MPZ_ONE<<wp), 2
else:
s, t, k = x, x, 3
while t:
t = (t*x2//(k*(k-1)))>>wp
s += t//k
k += 2
return from_man_exp(s, -wp)
def mpf_cos_sin_pi(x, prec, rnd=round_fast):
"""Accurate computation of (cos(pi*x), sin(pi*x))
for x close to an integer"""
sign, man, exp, bc = x
if not man:
return cos_sin(x, prec, rnd)
# Exactly an integer or half-integer?
if exp >= -1:
if exp == -1:
c = fzero
s = (fone, fnone)[bool(man & 2) ^ sign]
elif exp == 0:
c, s = (fnone, fzero)
else:
c, s = (fone, fzero)
return c, s
# Close to 0 ?
size = exp + bc
if size < -(prec+5):
c = mpf_perturb(fone, 1, prec, rnd)
s = mpf_perturb(mpf_mul(x, mpf_pi(prec)), sign, prec, rnd)
return c, s
if sign:
man = -man
# Subtract nearest half-integer (= modulo pi/2)
nhint = ((man >> (-exp-2)) + 1) >> 1
man = man - (nhint << (-exp-1))
x = from_man_exp(man, exp, prec)
x = mpf_mul(x, mpf_pi(prec), prec)
# XXX: with some more work, could call calc_cos_sin,
# to save some time and to get rounding right
case = nhint % 4
if case == 0:
c, s = cos_sin(x, prec, rnd)
elif case == 1:
s, c = cos_sin(x, prec, rnd)
c = mpf_neg(c)
elif case == 2:
c, s = cos_sin(x, prec, rnd)
c = mpf_neg(c)
s = mpf_neg(s)
else:
s, c = cos_sin(x, prec, rnd)
s = mpf_neg(s)
return c, s
def mpf_besseljn(n, x, prec, rounding=round_fast):
negate = n < 0 and n & 1
n = abs(n)
origprec = prec
prec += 20 + bitcount(abs(n))
x = to_fixed(x, prec)
x2 = (x**2) >> prec
if not n:
s = t = MP_ONE << prec
else:
s = t = (x**n // int_fac(n)) >> ((n - 1) * prec + n)
k = 1
while t:
t = ((t * x2) // (-4 * k * (k + n))) >> prec
s += t
k += 1
if negate:
s = -s
return from_man_exp(s, -prec, origprec, rounding)
def mpf_besseljn(n, x, prec):
negate = n < 0 and n & 1
n = abs(n)
origprec = prec
prec += 20 + bitcount(abs(n))
x = to_fixed(x, prec)
x2 = (x**2) >> prec
if not n:
s = t = MP_ONE << prec
else:
s = t = (x**n // int_fac(n)) >> ((n-1)*prec + n)
k = 1
while t:
t = ((t * x2) // (-4*k*(k+n))) >> prec
s += t
k += 1
if negate:
s = -s
return from_man_exp(s, -prec, origprec, round_nearest)
def mpf_exp(x, prec, rnd=round_fast):
sign, man, exp, bc = x
if man:
mag = bc + exp
wp = prec + 14
if sign:
man = -man
# TODO: the best cutoff depends on both x and the precision.
if prec > 600 and exp >= 0:
# Need about log2(exp(n)) ~= 1.45*mag extra precision
e = mpf_e(wp + int(1.45 * mag))
return mpf_pow_int(e, man << exp, prec, rnd)
if mag < -wp:
return mpf_perturb(fone, sign, prec, rnd)
# |x| >= 2
if mag > 1:
# For large arguments: exp(2^mag*(1+eps)) =
# exp(2^mag)*exp(2^mag*eps) = exp(2^mag)*(1 + 2^mag*eps + ...)
# so about mag extra bits is required.
wpmod = wp + mag
offset = exp + wpmod
if offset >= 0:
t = man << offset
else:
t = man >> (-offset)
lg2 = ln2_fixed(wpmod)
n, t = divmod(t, lg2)
n = int(n)
t >>= mag
else:
offset = exp + wp
if offset >= 0:
t = man << offset
else:
t = man >> (-offset)
n = 0
man = exp_basecase(t, wp)
return from_man_exp(man, n - wp, prec, rnd)
if not exp:
return fone
if x == fninf:
return fzero
return x
def cos_sin_fixed_prod(x, wp):
cos, sin = mpf_cos_sin(from_man_exp(x, -2*wp), wp)
sign, man, exp, bc = cos
if sign:
man = -man
offset = exp + wp
if offset >= 0:
cos = man << offset
else:
cos = man >> (-offset)
sign, man, exp, bc = sin
if sign:
man = -man
offset = exp + wp
if offset >= 0:
sin = man << offset
else:
sin = man >> (-offset)
return cos, sin
def cos_sin_fixed_prod(x, wp):
cos, sin = mpf_cos_sin(from_man_exp(x, -2 * wp), wp)
sign, man, exp, bc = cos
if sign:
man = -man
offset = exp + wp
if offset >= 0:
cos = man << offset
else:
cos = man >> (-offset)
sign, man, exp, bc = sin
if sign:
man = -man
offset = exp + wp
if offset >= 0:
sin = man << offset
else:
sin = man >> (-offset)
return cos, sin
def mpf_exp(x, prec, rnd=round_fast):
sign, man, exp, bc = x
if man:
mag = bc + exp
wp = prec + 14
if sign:
man = -man
# TODO: the best cutoff depends on both x and the precision.
if prec > 600 and exp >= 0:
# Need about log2(exp(n)) ~= 1.45*mag extra precision
e = mpf_e(wp + int(1.45 * mag))
return mpf_pow_int(e, man << exp, prec, rnd)
if mag < -wp:
return mpf_perturb(fone, sign, prec, rnd)
# |x| >= 2
if mag > 1:
# For large arguments: exp(2^mag*(1+eps)) =
# exp(2^mag)*exp(2^mag*eps) = exp(2^mag)*(1 + 2^mag*eps + ...)
# so about mag extra bits is required.
wpmod = wp + mag
offset = exp + wpmod
if offset >= 0:
t = man << offset
else:
t = man >> (-offset)
lg2 = ln2_fixed(wpmod)
n, t = divmod(t, lg2)
n = int(n)
t >>= mag
else:
offset = exp + wp
if offset >= 0:
t = man << offset
else:
t = man >> (-offset)
n = 0
man = exp_basecase(t, wp)
return from_man_exp(man, n - wp, prec, rnd)
if not exp:
return fone
if x == fninf:
return fzero
return x
def mpf_erfc(x, prec, rnd=round_fast):
sign, man, exp, bc = x
if not man:
if x == fzero: return fone
if x == finf: return fzero
if x == fninf: return ftwo
return fnan
wp = prec + 20
mag = bc + exp
# Preserve full accuracy when exponent grows huge
wp += max(0, 2 * mag)
regular_erf = sign or mag < 2
if regular_erf or not erfc_check_series(x, wp):
if regular_erf:
return mpf_sub(fone, mpf_erf(x, prec + 10, negative_rnd[rnd]),
prec, rnd)
# 1-erf(x) ~ exp(-x^2), increase prec to deal with cancellation
n = to_int(x)
return mpf_sub(fone, mpf_erf(x, prec + int(n**2 * 1.44) + 10), prec,
rnd)
s = term = MP_ONE << wp
term_prev = 0
t = (2 * to_fixed(x, wp)**2) >> wp
k = 1
while 1:
term = ((term * (2 * k - 1)) << wp) // t
if k > 4 and term > term_prev or not term:
break
if k & 1:
s -= term
else:
s += term
term_prev = term
#print k, to_str(from_man_exp(term, -wp, 50), 10)
k += 1
s = (s << wp) // sqrt_fixed(pi_fixed(wp), wp)
s = from_man_exp(s, -wp, wp)
z = mpf_exp(mpf_neg(mpf_mul(x, x, wp), wp), wp)
y = mpf_div(mpf_mul(z, s, wp), x, prec, rnd)
return y
def mpf_besseljn(n, x, prec, rounding=round_fast):
prec += 50
negate = n < 0 and n & 1
mag = x[2] + x[3]
n = abs(n)
wp = prec + 20 + n * bitcount(n)
if mag < 0:
wp -= n * mag
x = to_fixed(x, wp)
x2 = (x**2) >> wp
if not n:
s = t = MP_ONE << wp
else:
s = t = (x**n // int_fac(n)) >> ((n - 1) * wp + n)
k = 1
while t:
t = ((t * x2) // (-4 * k * (k + n))) >> wp
s += t
k += 1
if negate:
s = -s
return from_man_exp(s, -wp, prec, rounding)
def mpf_erf(x, prec, rnd=round_fast):
sign, man, exp, bc = x
if not man:
if x == fzero: return fzero
if x == finf: return fone
if x== fninf: return fnone
return fnan
size = exp + bc
lg = math.log
# The approximation erf(x) = 1 is accurate to > x^2 * log(e,2) bits
if size > 3 and 2*(size-1) + 0.528766 > lg(prec,2):
if sign:
return mpf_perturb(fnone, 0, prec, rnd)
else:
return mpf_perturb(fone, 1, prec, rnd)
# erf(x) ~ 2*x/sqrt(pi) close to 0
if size < -prec:
# 2*x
x = mpf_shift(x,1)
c = mpf_sqrt(mpf_pi(prec+20), prec+20)
# TODO: interval rounding
return mpf_div(x, c, prec, rnd)
wp = prec + abs(size) + 25
# Taylor series for erf, fixed-point summation
t = abs(to_fixed(x, wp))
t2 = (t*t) >> wp
s, term, k = t, 12345, 1
while term:
t = ((t * t2) >> wp) // k
term = t // (2*k+1)
if k & 1:
s -= term
else:
s += term
k += 1
s = (s << (wp+1)) // sqrt_fixed(pi_fixed(wp), wp)
if sign:
s = -s
return from_man_exp(s, -wp, prec, rnd)
def mpf_besseljn(n, x, prec, rounding=round_fast):
prec += 50
negate = n < 0 and n & 1
mag = x[2]+x[3]
n = abs(n)
wp = prec + 20 + n*bitcount(n)
if mag < 0:
wp -= n * mag
x = to_fixed(x, wp)
x2 = (x**2) >> wp
if not n:
s = t = MPZ_ONE << wp
else:
s = t = (x**n // ifac(n)) >> ((n-1)*wp + n)
k = 1
while t:
t = ((t * x2) // (-4*k*(k+n))) >> wp
s += t
k += 1
if negate:
s = -s
return from_man_exp(s, -wp, prec, rounding)
def mpf_erf(x, prec, rnd=round_fast):
sign, man, exp, bc = x
if not man:
if x == fzero: return fzero
if x == finf: return fone
if x == fninf: return fnone
return fnan
size = exp + bc
lg = math.log
# The approximation erf(x) = 1 is accurate to > x^2 * log(e,2) bits
if size > 3 and 2 * (size - 1) + 0.528766 > lg(prec, 2):
if sign:
return mpf_perturb(fnone, 0, prec, rnd)
else:
return mpf_perturb(fone, 1, prec, rnd)
# erf(x) ~ 2*x/sqrt(pi) close to 0
if size < -prec:
# 2*x
x = mpf_shift(x, 1)
c = mpf_sqrt(mpf_pi(prec + 20), prec + 20)
# TODO: interval rounding
return mpf_div(x, c, prec, rnd)
wp = prec + abs(size) + 20
# Taylor series for erf, fixed-point summation
t = abs(to_fixed(x, wp))
t2 = (t * t) >> wp
s, term, k = t, 12345, 1
while term:
t = ((t * t2) >> wp) // k
term = t // (2 * k + 1)
if k & 1:
s -= term
else:
s += term
k += 1
s = (s << (wp + 1)) // sqrt_fixed(pi_fixed(wp), wp)
if sign:
s = -s
return from_man_exp(s, -wp, wp, rnd)
def mpf_erfc(x, prec, rnd=round_fast):
sign, man, exp, bc = x
if not man:
if x == fzero: return fone
if x == finf: return fzero
if x == fninf: return ftwo
return fnan
wp = prec + 20
mag = bc+exp
# Preserve full accuracy when exponent grows huge
wp += max(0, 2*mag)
regular_erf = sign or mag < 2
if regular_erf or not erfc_check_series(x, wp):
if regular_erf:
return mpf_sub(fone, mpf_erf(x, prec+10, negative_rnd[rnd]), prec, rnd)
# 1-erf(x) ~ exp(-x^2), increase prec to deal with cancellation
n = to_int(x)+1
return mpf_sub(fone, mpf_erf(x, prec + int(n**2*1.44) + 10), prec, rnd)
s = term = MPZ_ONE << wp
term_prev = 0
t = (2 * to_fixed(x, wp) ** 2) >> wp
k = 1
while 1:
term = ((term * (2*k - 1)) << wp) // t
if k > 4 and term > term_prev or not term:
break
if k & 1:
s -= term
else:
s += term
term_prev = term
#print k, to_str(from_man_exp(term, -wp, 50), 10)
k += 1
s = (s << wp) // sqrt_fixed(pi_fixed(wp), wp)
s = from_man_exp(s, -wp, wp)
z = mpf_exp(mpf_neg(mpf_mul(x,x,wp),wp),wp)
y = mpf_div(mpf_mul(z, s, wp), x, prec, rnd)
return y
def __new__(cls, val=fzero, **kwargs):
"""A new mpf can be created from a Python float, an int, a
or a decimal string representing a number in floating-point
format."""
prec, rounding = prec_rounding
if kwargs:
prec = kwargs.get('prec', prec)
if 'dps' in kwargs:
prec = dps_to_prec(kwargs['dps'])
rounding = kwargs.get('rounding', rounding)
if type(val) is cls:
sign, man, exp, bc = val._mpf_
if (not man) and exp:
return val
return make_mpf(normalize(sign, man, exp, bc, prec, rounding))
elif type(val) is tuple:
if len(val) == 2:
return make_mpf(from_man_exp(val[0], val[1], prec, rounding))
if len(val) == 4:
sign, man, exp, bc = val
return make_mpf(normalize(sign, MP_BASE(man), exp, bc, prec, rounding))
raise ValueError
else:
return make_mpf(mpf_pos(mpf_convert_arg(val, prec, rounding), prec, rounding))
def __new__(cls, val=fzero, **kwargs):
"""A new mpf can be created from a Python float, an int, a
or a decimal string representing a number in floating-point
format."""
prec, rounding = prec_rounding
if kwargs:
prec = kwargs.get('prec', prec)
if 'dps' in kwargs:
prec = dps_to_prec(kwargs['dps'])
rounding = kwargs.get('rounding', rounding)
if type(val) is cls:
sign, man, exp, bc = val._mpf_
if (not man) and exp:
return val
return make_mpf(normalize(sign, man, exp, bc, prec, rounding))
elif type(val) is tuple:
if len(val) == 2:
return make_mpf(from_man_exp(val[0], val[1], prec, rounding))
if len(val) == 4:
sign, man, exp, bc = val
return make_mpf(normalize(sign, MP_BASE(man), exp, bc, prec, rounding))
raise ValueError
else:
return make_mpf(mpf_pos(mpf_convert_arg(val, prec, rounding), prec, rounding))
def _djacobi_theta3(z, q, nd):
"""nd=1,2,3 order of the derivative with respect to z"""
MIN = 2
extra1 = 10
extra2 = 20
if isinstance(q, mpf) and isinstance(z, mpf):
s = MP_ZERO
wp = mp.prec + extra1
x = to_fixed(q._mpf_, wp)
a = b = x
x2 = (x*x) >> wp
c1, s1 = cos_sin(mpf_shift(z._mpf_, 1), wp)
c1 = to_fixed(c1, wp)
s1 = to_fixed(s1, wp)
cn = c1
sn = s1
if (nd&1):
s += (a * sn) >> wp
else:
s += (a * cn) >> wp
n = 2
while abs(a) > MIN:
b = (b*x2) >> wp
a = (a*b) >> wp
cn, sn = (cn*c1 - sn*s1) >> wp, (sn*c1 + cn*s1) >> wp
if nd&1:
s += (a * sn * n**nd) >> wp
else:
s += (a * cn * n**nd) >> wp
n += 1
s = -(s << (nd+1))
s = mpf(from_man_exp(s, -wp, mp.prec, 'n'))
# case z real, q complex
elif isinstance(z, mpf):
wp = mp.prec + extra2
xre, xim = q._mpc_
xre = to_fixed(xre, wp)
xim = to_fixed(xim, wp)
x2re = (xre*xre - xim*xim) >> wp
x2im = (xre*xim) >> (wp - 1)
are = bre = xre
aim = bim = xim
c1, s1 = cos_sin(mpf_shift(z._mpf_, 1), wp)
c1 = to_fixed(c1, wp)
s1 = to_fixed(s1, wp)
cn = c1
sn = s1
if (nd&1):
sre = (are * sn) >> wp
sim = (aim * sn) >> wp
else:
sre = (are * cn) >> wp
sim = (aim * cn) >> wp
n = 2
while are**2 + aim**2 > MIN:
bre, bim = (bre * x2re - bim * x2im) >> wp, \
(bre * x2im + bim * x2re) >> wp
are, aim = (are * bre - aim * bim) >> wp, \
(are * bim + aim * bre) >> wp
cn, sn = (cn*c1 - sn*s1) >> wp, (sn*c1 + cn*s1) >> wp
if nd&1:
sre += (are * sn * n**nd) >> wp
sim += (aim * sn * n**nd) >> wp
else:
sre += (are * cn * n**nd) >> wp
sim += (aim * cn * n**nd) >> wp
n += 1
sre = -(sre << (nd+1))
sim = -(sim << (nd+1))
sre = from_man_exp(sre, -wp, mp.prec, 'n')
sim = from_man_exp(sim, -wp, mp.prec, 'n')
s = mpc(sre, sim)
#case z complex, q real
elif isinstance(q, mpf):
wp = mp.prec + extra2
x = to_fixed(q._mpf_, wp)
a = b = x
x2 = (x*x) >> wp
prec0 = mp.prec
mp.prec = wp
c1 = cos(2*z)
s1 = sin(2*z)
mp.prec = prec0
cnre = c1re = to_fixed(c1.real._mpf_, wp)
cnim = c1im = to_fixed(c1.imag._mpf_, wp)
snre = s1re = to_fixed(s1.real._mpf_, wp)
snim = s1im = to_fixed(s1.imag._mpf_, wp)
if (nd&1):
sre = (a * snre) >> wp
sim = (a * snim) >> wp
else:
sre = (a * cnre) >> wp
sim = (a * cnim) >> wp
n = 2
while abs(a) > MIN:
b = (b*x2) >> wp
a = (a*b) >> wp
t1 = (cnre*c1re - cnim*c1im - snre*s1re + snim*s1im) >> wp
t2 = (cnre*c1im + cnim*c1re - snre*s1im - snim*s1re) >> wp
t3 = (snre*c1re - snim*c1im + cnre*s1re - cnim*s1im) >> wp
t4 = (snre*c1im + snim*c1re + cnre*s1im + cnim*s1re) >> wp
cnre = t1
cnim = t2
snre = t3
snim = t4
if (nd&1):
sre += (a * snre * n**nd) >> wp
sim += (a * snim * n**nd) >> wp
else:
sre += (a * cnre * n**nd) >> wp
sim += (a * cnim * n**nd) >> wp
n += 1
sre = -(sre << (nd+1))
sim = -(sim << (nd+1))
sre = from_man_exp(sre, -wp, mp.prec, 'n')
sim = from_man_exp(sim, -wp, mp.prec, 'n')
s = mpc(sre, sim)
# case z and q complex
else:
wp = mp.prec + extra2
xre, xim = q._mpc_
xre = to_fixed(xre, wp)
xim = to_fixed(xim, wp)
x2re = (xre*xre - xim*xim) >> wp
x2im = (xre*xim) >> (wp - 1)
are = bre = xre
aim = bim = xim
prec0 = mp.prec
mp.prec = wp
# cos(2*z), sin(2*z) with z complex
c1 = cos(2*z)
s1 = sin(2*z)
mp.prec = prec0
cnre = c1re = to_fixed(c1.real._mpf_, wp)
cnim = c1im = to_fixed(c1.imag._mpf_, wp)
snre = s1re = to_fixed(s1.real._mpf_, wp)
snim = s1im = to_fixed(s1.imag._mpf_, wp)
if (nd&1):
sre = (are * snre - aim * snim) >> wp
sim = (aim * snre + are * snim) >> wp
else:
sre = (are * cnre - aim * cnim) >> wp
sim = (aim * cnre + are * cnim) >> wp
n = 2
while are**2 + aim**2 > MIN:
bre, bim = (bre * x2re - bim * x2im) >> wp, \
(bre * x2im + bim * x2re) >> wp
are, aim = (are * bre - aim * bim) >> wp, \
(are * bim + aim * bre) >> wp
t1 = (cnre*c1re - cnim*c1im - snre*s1re + snim*s1im) >> wp
t2 = (cnre*c1im + cnim*c1re - snre*s1im - snim*s1re) >> wp
t3 = (snre*c1re - snim*c1im + cnre*s1re - cnim*s1im) >> wp
t4 = (snre*c1im + snim*c1re + cnre*s1im + cnim*s1re) >> wp
cnre = t1
cnim = t2
snre = t3
snim = t4
if(nd&1):
sre += ((are * snre - aim * snim) * n**nd) >> wp
sim += ((aim * snre + are * snim) * n**nd) >> wp
else:
sre += ((are * cnre - aim * cnim) * n**nd) >> wp
sim += ((aim * cnre + are * cnim) * n**nd) >> wp
n += 1
sre = -(sre << (nd+1))
sim = -(sim << (nd+1))
sre = from_man_exp(sre, -wp, mp.prec, 'n')
sim = from_man_exp(sim, -wp, mp.prec, 'n')
s = mpc(sre, sim)
if (nd&1):
return (-1)**(nd//2) * s
else:
return (-1)**(1 + nd//2) * s
def _jacobi_theta2(z, q):
extra1 = 10
extra2 = 20
# the loops below break when the fixed precision quantities
# a and b go to zero;
# right shifting small negative numbers by wp one obtains -1, not zero,
# so the condition a**2 + b**2 > MIN is used to break the loops.
MIN = 2
if z == zero:
if isinstance(q, mpf):
wp = mp.prec + extra1
x = to_fixed(q._mpf_, wp)
x2 = (x*x) >> wp
a = b = x2
s = x2
while abs(a) > MIN:
b = (b*x2) >> wp
a = (a*b) >> wp
s += a
s = (1 << (wp+1)) + (s << 1)
s = mpf(from_man_exp(s, -wp, mp.prec, 'n'))
else:
wp = mp.prec + extra1
xre, xim = q._mpc_
xre = to_fixed(xre, wp)
xim = to_fixed(xim, wp)
x2re = (xre*xre - xim*xim) >> wp
x2im = (xre*xim) >> (wp - 1)
are = bre = x2re
aim = bim = x2im
sre = (1<<wp) + are
sim = aim
while are**2 + aim**2 > MIN:
bre, bim = (bre * x2re - bim * x2im) >> wp, \
(bre * x2im + bim * x2re) >> wp
are, aim = (are * bre - aim * bim) >> wp, \
(are * bim + aim * bre) >> wp
sre += are
sim += aim
sre = (sre << 1)
sim = (sim << 1)
sre = from_man_exp(sre, -wp, mp.prec, 'n')
sim = from_man_exp(sim, -wp, mp.prec, 'n')
s = mpc(sre, sim)
else:
if isinstance(q, mpf) and isinstance(z, mpf):
wp = mp.prec + extra1
x = to_fixed(q._mpf_, wp)
x2 = (x*x) >> wp
a = b = x2
c1, s1 = cos_sin(z._mpf_, wp)
cn = c1 = to_fixed(c1, wp)
sn = s1 = to_fixed(s1, wp)
c2 = (c1*c1 - s1*s1) >> wp
s2 = (c1 * s1) >> (wp - 1)
cn, sn = (cn*c2 - sn*s2) >> wp, (sn*c2 + cn*s2) >> wp
s = c1 + ((a * cn) >> wp)
while abs(a) > MIN:
b = (b*x2) >> wp
a = (a*b) >> wp
cn, sn = (cn*c2 - sn*s2) >> wp, (sn*c2 + cn*s2) >> wp
s += (a * cn) >> wp
s = (s << 1)
s = mpf(from_man_exp(s, -wp, mp.prec, 'n'))
s *= nthroot(q, 4)
return s
# case z real, q complex
elif isinstance(z, mpf):
wp = mp.prec + extra2
xre, xim = q._mpc_
xre = to_fixed(xre, wp)
xim = to_fixed(xim, wp)
x2re = (xre*xre - xim*xim) >> wp
x2im = (xre*xim) >> (wp - 1)
are = bre = x2re
aim = bim = x2im
c1, s1 = cos_sin(z._mpf_, wp)
cn = c1 = to_fixed(c1, wp)
sn = s1 = to_fixed(s1, wp)
c2 = (c1*c1 - s1*s1) >> wp
s2 = (c1 * s1) >> (wp - 1)
cn, sn = (cn*c2 - sn*s2) >> wp, (sn*c2 + cn*s2) >> wp
sre = c1 + ((are * cn) >> wp)
sim = ((aim * cn) >> wp)
while are**2 + aim**2 > MIN:
bre, bim = (bre * x2re - bim * x2im) >> wp, \
(bre * x2im + bim * x2re) >> wp
are, aim = (are * bre - aim * bim) >> wp, \
(are * bim + aim * bre) >> wp
cn, sn = (cn*c2 - sn*s2) >> wp, (sn*c2 + cn*s2) >> wp
sre += ((are * cn) >> wp)
sim += ((aim * cn) >> wp)
sre = (sre << 1)
sim = (sim << 1)
sre = from_man_exp(sre, -wp, mp.prec, 'n')
sim = from_man_exp(sim, -wp, mp.prec, 'n')
s = mpc(sre, sim)
#case z complex, q real
elif isinstance(q, mpf):
wp = mp.prec + extra2
x = to_fixed(q._mpf_, wp)
x2 = (x*x) >> wp
a = b = x2
prec0 = mp.prec
mp.prec = wp
c1 = cos(z)
s1 = sin(z)
mp.prec = prec0
cnre = c1re = to_fixed(c1.real._mpf_, wp)
cnim = c1im = to_fixed(c1.imag._mpf_, wp)
snre = s1re = to_fixed(s1.real._mpf_, wp)
snim = s1im = to_fixed(s1.imag._mpf_, wp)
#c2 = (c1*c1 - s1*s1) >> wp
c2re = (c1re*c1re - c1im*c1im - s1re*s1re + s1im*s1im) >> wp
c2im = (c1re*c1im - s1re*s1im) >> (wp - 1)
#s2 = (c1 * s1) >> (wp - 1)
s2re = (c1re*s1re - c1im*s1im) >> (wp - 1)
s2im = (c1re*s1im + c1im*s1re) >> (wp - 1)
#cn, sn = (cn*c2 - sn*s2) >> wp, (sn*c2 + cn*s2) >> wp
t1 = (cnre*c2re - cnim*c2im - snre*s2re + snim*s2im) >> wp
t2 = (cnre*c2im + cnim*c2re - snre*s2im - snim*s2re) >> wp
t3 = (snre*c2re - snim*c2im + cnre*s2re - cnim*s2im) >> wp
t4 = (snre*c2im + snim*c2re + cnre*s2im + cnim*s2re) >> wp
cnre = t1
cnim = t2
snre = t3
snim = t4
sre = c1re + ((a * cnre) >> wp)
sim = c1im + ((a * cnim) >> wp)
while abs(a) > MIN:
b = (b*x2) >> wp
a = (a*b) >> wp
t1 = (cnre*c2re - cnim*c2im - snre*s2re + snim*s2im) >> wp
t2 = (cnre*c2im + cnim*c2re - snre*s2im - snim*s2re) >> wp
t3 = (snre*c2re - snim*c2im + cnre*s2re - cnim*s2im) >> wp
t4 = (snre*c2im + snim*c2re + cnre*s2im + cnim*s2re) >> wp
cnre = t1
cnim = t2
snre = t3
snim = t4
sre += ((a * cnre) >> wp)
sim += ((a * cnim) >> wp)
sre = (sre << 1)
sim = (sim << 1)
sre = from_man_exp(sre, -wp, mp.prec, 'n')
sim = from_man_exp(sim, -wp, mp.prec, 'n')
s = mpc(sre, sim)
# case z and q complex
else:
wp = mp.prec + extra2
xre, xim = q._mpc_
xre = to_fixed(xre, wp)
xim = to_fixed(xim, wp)
x2re = (xre*xre - xim*xim) >> wp
x2im = (xre*xim) >> (wp - 1)
are = bre = x2re
aim = bim = x2im
prec0 = mp.prec
mp.prec = wp
# cos(z), siz(z) with z complex
c1 = cos(z)
s1 = sin(z)
mp.prec = prec0
cnre = c1re = to_fixed(c1.real._mpf_, wp)
cnim = c1im = to_fixed(c1.imag._mpf_, wp)
snre = s1re = to_fixed(s1.real._mpf_, wp)
snim = s1im = to_fixed(s1.imag._mpf_, wp)
c2re = (c1re*c1re - c1im*c1im - s1re*s1re + s1im*s1im) >> wp
c2im = (c1re*c1im - s1re*s1im) >> (wp - 1)
s2re = (c1re*s1re - c1im*s1im) >> (wp - 1)
s2im = (c1re*s1im + c1im*s1re) >> (wp - 1)
t1 = (cnre*c2re - cnim*c2im - snre*s2re + snim*s2im) >> wp
t2 = (cnre*c2im + cnim*c2re - snre*s2im - snim*s2re) >> wp
t3 = (snre*c2re - snim*c2im + cnre*s2re - cnim*s2im) >> wp
t4 = (snre*c2im + snim*c2re + cnre*s2im + cnim*s2re) >> wp
cnre = t1
cnim = t2
snre = t3
snim = t4
n = 1
termre = c1re
termim = c1im
sre = c1re + ((are * cnre - aim * cnim) >> wp)
sim = c1im + ((are * cnim + aim * cnre) >> wp)
n = 3
termre = ((are * cnre - aim * cnim) >> wp)
termim = ((are * cnim + aim * cnre) >> wp)
sre = c1re + ((are * cnre - aim * cnim) >> wp)
sim = c1im + ((are * cnim + aim * cnre) >> wp)
n = 5
while are**2 + aim**2 > MIN:
bre, bim = (bre * x2re - bim * x2im) >> wp, \
(bre * x2im + bim * x2re) >> wp
are, aim = (are * bre - aim * bim) >> wp, \
(are * bim + aim * bre) >> wp
#cn, sn = (cn*c1 - sn*s1) >> wp, (sn*c1 + cn*s1) >> wp
t1 = (cnre*c2re - cnim*c2im - snre*s2re + snim*s2im) >> wp
t2 = (cnre*c2im + cnim*c2re - snre*s2im - snim*s2re) >> wp
t3 = (snre*c2re - snim*c2im + cnre*s2re - cnim*s2im) >> wp
t4 = (snre*c2im + snim*c2re + cnre*s2im + cnim*s2re) >> wp
cnre = t1
cnim = t2
snre = t3
snim = t4
termre = ((are * cnre - aim * cnim) >> wp)
termim = ((aim * cnre + are * cnim) >> wp)
sre += ((are * cnre - aim * cnim) >> wp)
sim += ((aim * cnre + are * cnim) >> wp)
n += 2
sre = (sre << 1)
sim = (sim << 1)
sre = from_man_exp(sre, -wp, mp.prec, 'n')
sim = from_man_exp(sim, -wp, mp.prec, 'n')
s = mpc(sre, sim)
s *= nthroot(q, 4)
return s
