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 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 mpc_agm(a, b, prec, rnd=round_fast):
"""
Complex AGM.
TODO:
* check that convergence works as intended
* optimize
* select a nonarbitrary branch
"""
if mpc_is_infnan(a) or mpc_is_infnan(b):
return fnan, fnan
if mpc_zero in (a, b):
return fzero, fzero
if mpc_neg(a) == b:
return fzero, fzero
wp = prec+20
eps = mpf_shift(fone, -wp+10)
while 1:
a1 = mpc_shift(mpc_add(a, b, wp), -1)
b1 = mpc_sqrt(mpc_mul(a, b, wp), wp)
a, b = a1, b1
size = mpf_min_max([mpc_abs(a,10), mpc_abs(b,10)])[1]
err = mpc_abs(mpc_sub(a, b, 10), 10)
if size == fzero or mpf_lt(err, mpf_mul(eps, size)):
return a
def mpc_agm(a, b, prec, rnd=round_fast):
"""
Complex AGM.
TODO:
* check that convergence works as intended
* optimize
* select a nonarbitrary branch
"""
if mpc_is_infnan(a) or mpc_is_infnan(b):
return fnan, fnan
if mpc_zero in (a, b):
return fzero, fzero
if mpc_neg(a) == b:
return fzero, fzero
wp = prec + 20
eps = mpf_shift(fone, -wp + 10)
while 1:
a1 = mpc_shift(mpc_add(a, b, wp), -1)
b1 = mpc_sqrt(mpc_mul(a, b, wp), wp)
a, b = a1, b1
size = mpf_min_max([mpc_abs(a, 10), mpc_abs(b, 10)])[1]
err = mpc_abs(mpc_sub(a, b, 10), 10)
if size == fzero or mpf_lt(err, mpf_mul(eps, size)):
return a
def mpi_square(s, prec=0):
sa, sb = s
if mpf_ge(sa, fzero):
a = mpf_mul(sa, sa, prec, round_floor)
b = mpf_mul(sb, sb, prec, round_ceiling)
elif mpf_le(sb, fzero):
a = mpf_mul(sb, sb, prec, round_floor)
b = mpf_mul(sa, sa, prec, round_ceiling)
else:
sa = mpf_neg(sa)
sa, sb = mpf_min_max([sa, sb])
a = fzero
b = mpf_mul(sb, sb, prec, round_ceiling)
return a, b
def mpi_square(s, prec=0):
sa, sb = s
if mpf_ge(sa, fzero):
a = mpf_mul(sa, sa, prec, round_floor)
b = mpf_mul(sb, sb, prec, round_ceiling)
elif mpf_le(sb, fzero):
a = mpf_mul(sb, sb, prec, round_floor)
b = mpf_mul(sa, sa, prec, round_ceiling)
else:
sa = mpf_neg(sa)
sa, sb = mpf_min_max([sa, sb])
a = fzero
b = mpf_mul(sb, sb, prec, round_ceiling)
return a, b
def mpi_mul(s, t, prec=0):
sa, sb = s
ta, tb = t
sas = mpf_sign(sa)
sbs = mpf_sign(sb)
tas = mpf_sign(ta)
tbs = mpf_sign(tb)
if sas == sbs == 0:
# Should maybe be undefined
if ta == fninf or tb == finf:
return fninf, finf
return fzero, fzero
if tas == tbs == 0:
# Should maybe be undefined
if sa == fninf or sb == finf:
return fninf, finf
return fzero, fzero
if sas >= 0:
# positive * positive
if tas >= 0:
a = mpf_mul(sa, ta, prec, round_floor)
b = mpf_mul(sb, tb, prec, round_ceiling)
if a == fnan: a = fzero
if b == fnan: b = finf
# positive * negative
elif tbs <= 0:
a = mpf_mul(sb, ta, prec, round_floor)
b = mpf_mul(sa, tb, prec, round_ceiling)
if a == fnan: a = fninf
if b == fnan: b = fzero
# positive * both signs
else:
a = mpf_mul(sb, ta, prec, round_floor)
b = mpf_mul(sb, tb, prec, round_ceiling)
if a == fnan: a = fninf
if b == fnan: b = finf
elif sbs <= 0:
# negative * positive
if tas >= 0:
a = mpf_mul(sa, tb, prec, round_floor)
b = mpf_mul(sb, ta, prec, round_ceiling)
if a == fnan: a = fninf
if b == fnan: b = fzero
# negative * negative
elif tbs <= 0:
a = mpf_mul(sb, tb, prec, round_floor)
b = mpf_mul(sa, ta, prec, round_ceiling)
if a == fnan: a = fzero
if b == fnan: b = finf
# negative * both signs
else:
a = mpf_mul(sa, tb, prec, round_floor)
b = mpf_mul(sa, ta, prec, round_ceiling)
if a == fnan: a = fninf
if b == fnan: b = finf
else:
# General case: perform all cross-multiplications and compare
# Since the multiplications can be done exactly, we need only
# do 4 (instead of 8: two for each rounding mode)
cases = [
mpf_mul(sa, ta),
mpf_mul(sa, tb),
mpf_mul(sb, ta),
mpf_mul(sb, tb)
]
if fnan in cases:
a, b = (fninf, finf)
else:
a, b = mpf_min_max(cases)
a = mpf_pos(a, prec, round_floor)
b = mpf_pos(b, prec, round_ceiling)
return a, b
def mpi_mul(s, t, prec=0):
sa, sb = s
ta, tb = t
sas = mpf_sign(sa)
sbs = mpf_sign(sb)
tas = mpf_sign(ta)
tbs = mpf_sign(tb)
if sas == sbs == 0:
# Should maybe be undefined
if ta == fninf or tb == finf:
return fninf, finf
return fzero, fzero
if tas == tbs == 0:
# Should maybe be undefined
if sa == fninf or sb == finf:
return fninf, finf
return fzero, fzero
if sas >= 0:
# positive * positive
if tas >= 0:
a = mpf_mul(sa, ta, prec, round_floor)
b = mpf_mul(sb, tb, prec, round_ceiling)
if a == fnan: a = fzero
if b == fnan: b = finf
# positive * negative
elif tbs <= 0:
a = mpf_mul(sb, ta, prec, round_floor)
b = mpf_mul(sa, tb, prec, round_ceiling)
if a == fnan: a = fninf
if b == fnan: b = fzero
# positive * both signs
else:
a = mpf_mul(sb, ta, prec, round_floor)
b = mpf_mul(sb, tb, prec, round_ceiling)
if a == fnan: a = fninf
if b == fnan: b = finf
elif sbs <= 0:
# negative * positive
if tas >= 0:
a = mpf_mul(sa, tb, prec, round_floor)
b = mpf_mul(sb, ta, prec, round_ceiling)
if a == fnan: a = fninf
if b == fnan: b = fzero
# negative * negative
elif tbs <= 0:
a = mpf_mul(sb, tb, prec, round_floor)
b = mpf_mul(sa, ta, prec, round_ceiling)
if a == fnan: a = fzero
if b == fnan: b = finf
# negative * both signs
else:
a = mpf_mul(sa, tb, prec, round_floor)
b = mpf_mul(sa, ta, prec, round_ceiling)
if a == fnan: a = fninf
if b == fnan: b = finf
else:
# General case: perform all cross-multiplications and compare
# Since the multiplications can be done exactly, we need only
# do 4 (instead of 8: two for each rounding mode)
cases = [mpf_mul(sa, ta), mpf_mul(sa, tb), mpf_mul(sb, ta), mpf_mul(sb, tb)]
if fnan in cases:
a, b = (fninf, finf)
else:
a, b = mpf_min_max(cases)
a = mpf_pos(a, prec, round_floor)
b = mpf_pos(b, prec, round_ceiling)
return a, b
