def mpi_pow_int(s, n, prec):
sa, sb = s
if n < 0:
return mpi_div((fone, fone), mpi_pow_int(s, -n, prec + 20), prec)
if n == 0:
return (fone, fone)
if n == 1:
return s
# Odd -- signs are preserved
if n & 1:
a = mpf_pow_int(sa, n, prec, round_floor)
b = mpf_pow_int(sb, n, prec, round_ceiling)
# Even -- important to ensure positivity
else:
sas = mpf_sign(sa)
sbs = mpf_sign(sb)
# Nonnegative?
if sas >= 0:
a = mpf_pow_int(sa, n, prec, round_floor)
b = mpf_pow_int(sb, n, prec, round_ceiling)
# Nonpositive?
elif sbs <= 0:
a = mpf_pow_int(sb, n, prec, round_floor)
b = mpf_pow_int(sa, n, prec, round_ceiling)
# Mixed signs?
else:
a = fzero
# max(-a,b)**n
sa = mpf_neg(sa)
if mpf_ge(sa, sb):
b = mpf_pow_int(sa, n, prec, round_ceiling)
else:
b = mpf_pow_int(sb, n, prec, round_ceiling)
return a, b
def mpi_pow_int(s, n, prec):
sa, sb = s
if n < 0:
return mpi_div((fone, fone), mpi_pow_int(s, -n, prec+20), prec)
if n == 0:
return (fone, fone)
if n == 1:
return s
# Odd -- signs are preserved
if n & 1:
a = mpf_pow_int(sa, n, prec, round_floor)
b = mpf_pow_int(sb, n, prec, round_ceiling)
# Even -- important to ensure positivity
else:
sas = mpf_sign(sa)
sbs = mpf_sign(sb)
# Nonnegative?
if sas >= 0:
a = mpf_pow_int(sa, n, prec, round_floor)
b = mpf_pow_int(sb, n, prec, round_ceiling)
# Nonpositive?
elif sbs <= 0:
a = mpf_pow_int(sb, n, prec, round_floor)
b = mpf_pow_int(sa, n, prec, round_ceiling)
# Mixed signs?
else:
a = fzero
# max(-a,b)**n
sa = mpf_neg(sa)
if mpf_ge(sa, sb):
b = mpf_pow_int(sa, n, prec, round_ceiling)
else:
b = mpf_pow_int(sb, n, prec, round_ceiling)
return a, b
def mpi_div(s, t, prec):
sa, sb = s
ta, tb = t
sas = mpf_sign(sa)
sbs = mpf_sign(sb)
tas = mpf_sign(ta)
tbs = mpf_sign(tb)
# 0 / X
if sas == sbs == 0:
# 0 / <interval containing 0>
if (tas < 0 and tbs > 0) or (tas == 0 or tbs == 0):
return fninf, finf
return fzero, fzero
# Denominator contains both negative and positive numbers;
# this should properly be a multi-interval, but the closest
# match is the entire (extended) real line
if tas < 0 and tbs > 0:
return fninf, finf
# Assume denominator to be nonnegative
if tas < 0:
return mpi_div(mpi_neg(s), mpi_neg(t), prec)
# Division by zero
# XXX: make sure all results make sense
if tas == 0:
# Numerator contains both signs?
if sas < 0 and sbs > 0:
return fninf, finf
if tas == tbs:
return fninf, finf
# Numerator positive?
if sas >= 0:
a = mpf_div(sa, tb, prec, round_floor)
b = finf
if sbs <= 0:
a = fninf
b = mpf_div(sb, tb, prec, round_ceiling)
# Division with positive denominator
# We still have to handle nans resulting from inf/0 or inf/inf
else:
# Nonnegative numerator
if sas >= 0:
a = mpf_div(sa, tb, prec, round_floor)
b = mpf_div(sb, ta, prec, round_ceiling)
if a == fnan: a = fzero
if b == fnan: b = finf
# Nonpositive numerator
elif sbs <= 0:
a = mpf_div(sa, ta, prec, round_floor)
b = mpf_div(sb, tb, prec, round_ceiling)
if a == fnan: a = fninf
if b == fnan: b = fzero
# Numerator contains both signs?
else:
a = mpf_div(sa, ta, prec, round_floor)
b = mpf_div(sb, ta, prec, round_ceiling)
if a == fnan: a = fninf
if b == fnan: b = finf
return a, b
def mpi_div(s, t, prec):
sa, sb = s
ta, tb = t
sas = mpf_sign(sa)
sbs = mpf_sign(sb)
tas = mpf_sign(ta)
tbs = mpf_sign(tb)
# 0 / X
if sas == sbs == 0:
# 0 / <interval containing 0>
if (tas < 0 and tbs > 0) or (tas == 0 or tbs == 0):
return fninf, finf
return fzero, fzero
# Denominator contains both negative and positive numbers;
# this should properly be a multi-interval, but the closest
# match is the entire (extended) real line
if tas < 0 and tbs > 0:
return fninf, finf
# Assume denominator to be nonnegative
if tas < 0:
return mpi_div(mpi_neg(s), mpi_neg(t), prec)
# Division by zero
# XXX: make sure all results make sense
if tas == 0:
# Numerator contains both signs?
if sas < 0 and sbs > 0:
return fninf, finf
if tas == tbs:
return fninf, finf
# Numerator positive?
if sas >= 0:
a = mpf_div(sa, tb, prec, round_floor)
b = finf
if sbs <= 0:
a = fninf
b = mpf_div(sb, tb, prec, round_ceiling)
# Division with positive denominator
# We still have to handle nans resulting from inf/0 or inf/inf
else:
# Nonnegative numerator
if sas >= 0:
a = mpf_div(sa, tb, prec, round_floor)
b = mpf_div(sb, ta, prec, round_ceiling)
if a == fnan: a = fzero
if b == fnan: b = finf
# Nonpositive numerator
elif sbs <= 0:
a = mpf_div(sa, ta, prec, round_floor)
b = mpf_div(sb, tb, prec, round_ceiling)
if a == fnan: a = fninf
if b == fnan: b = fzero
# Numerator contains both signs?
else:
a = mpf_div(sa, ta, prec, round_floor)
b = mpf_div(sb, ta, prec, round_ceiling)
if a == fnan: a = fninf
if b == fnan: b = finf
return a, b
def mpf_atan2(y, x, prec, rnd=round_fast):
xsign, xman, xexp, xbc = x
ysign, yman, yexp, ybc = y
if not yman:
if y == fnan or x == fnan:
return fnan
if mpf_sign(x) >= 0:
return fzero
return mpf_pi(prec, rnd)
if ysign:
return mpf_neg(mpf_atan2(mpf_neg(y), x, prec, rnd))
if not xman:
if x == fnan:
return fnan
if x == finf:
return fzero
if x == fninf:
return mpf_pi(prec, rnd)
if not yman:
return fzero
return mpf_shift(mpf_pi(prec, rnd), -1)
tquo = mpf_atan(mpf_div(y, x, prec+4), prec+4)
if xsign:
return mpf_add(mpf_pi(prec+4), tquo, prec, rnd)
else:
return mpf_pos(tquo, prec, rnd)
def mpf_atan2(y, x, prec, rnd=round_fast):
xsign, xman, xexp, xbc = x
ysign, yman, yexp, ybc = y
if not yman:
if y == fzero and x != fnan:
if mpf_sign(x) >= 0:
return fzero
return mpf_pi(prec, rnd)
if y in (finf, fninf):
if x in (finf, fninf):
return fnan
# pi/2
if y == finf:
return mpf_shift(mpf_pi(prec, rnd), -1)
# -pi/2
return mpf_neg(mpf_shift(mpf_pi(prec, negative_rnd[rnd]), -1))
return fnan
if ysign:
return mpf_neg(mpf_atan2(mpf_neg(y), x, prec, negative_rnd[rnd]))
if not xman:
if x == fnan:
return fnan
if x == finf:
return fzero
if x == fninf:
return mpf_pi(prec, rnd)
if y == fzero:
return fzero
return mpf_shift(mpf_pi(prec, rnd), -1)
tquo = mpf_atan(mpf_div(y, x, prec+4), prec+4)
if xsign:
return mpf_add(mpf_pi(prec+4), tquo, prec, rnd)
else:
return mpf_pos(tquo, prec, rnd)
def mpf_atan2(y, x, prec, rnd=round_fast):
xsign, xman, xexp, xbc = x
ysign, yman, yexp, ybc = y
if not yman:
if y == fnan or x == fnan:
return fnan
if mpf_sign(x) >= 0:
return fzero
return mpf_pi(prec, rnd)
if ysign:
return mpf_neg(mpf_atan2(mpf_neg(y), x, prec, rnd))
if not xman:
if x == fnan:
return fnan
if x == finf:
return fzero
if x == fninf:
return mpf_pi(prec, rnd)
if not yman:
return fzero
return mpf_shift(mpf_pi(prec, rnd), -1)
tquo = mpf_atan(mpf_div(y, x, prec + 4), prec + 4)
if xsign:
return mpf_add(mpf_pi(prec + 4), tquo, prec, rnd)
else:
return mpf_pos(tquo, prec, rnd)
def mpi_abs(s, prec):
sa, sb = s
sas = mpf_sign(sa)
sbs = mpf_sign(sb)
# Both points nonnegative?
if sas >= 0:
a = mpf_pos(sa, prec, round_floor)
b = mpf_pos(sb, prec, round_ceiling)
# Upper point nonnegative?
elif sbs >= 0:
a = fzero
negsa = mpf_neg(sa)
if mpf_lt(negsa, sb):
b = mpf_pos(sb, prec, round_ceiling)
else:
b = mpf_pos(negsa, prec, round_ceiling)
# Both negative?
else:
a = mpf_neg(sb, prec, round_floor)
b = mpf_neg(sa, prec, round_ceiling)
return a, b
def mpi_abs(s, prec):
sa, sb = s
sas = mpf_sign(sa)
sbs = mpf_sign(sb)
# Both points nonnegative?
if sas >= 0:
a = mpf_pos(sa, prec, round_floor)
b = mpf_pos(sb, prec, round_ceiling)
# Upper point nonnegative?
elif sbs >= 0:
a = fzero
negsa = mpf_neg(sa)
if mpf_lt(negsa, sb):
b = mpf_pos(sb, prec, round_ceiling)
else:
b = mpf_pos(negsa, prec, round_ceiling)
# Both negative?
else:
a = mpf_neg(sb, prec, round_floor)
b = mpf_neg(sa, prec, round_ceiling)
return a, b
def mpc_ci(z, prec, rnd=round_fast):
re, im = z
if im == fzero:
ci = mpf_ci_si(re, prec, rnd, 0)[0]
if mpf_sign(re) < 0:
return (ci, mpf_pi(prec, rnd))
return (ci, fzero)
wp = prec + 20
cre, cim = mpc_ci_si_taylor(re, im, wp, 0)
cre = mpf_add(cre, mpf_euler(wp), wp)
ci = mpc_add((cre, cim), mpc_log(z, wp), prec, rnd)
return ci
def mpc_ci(z, prec, rnd=round_fast):
re, im = z
if im == fzero:
ci = mpf_ci_si(re, prec, rnd, 0)[0]
if mpf_sign(re) < 0:
return (ci, mpf_pi(prec, rnd))
return (ci, fzero)
wp = prec + 20
cre, cim = mpc_ci_si_taylor(re, im, wp, 0)
cre = mpf_add(cre, mpf_euler(wp), wp)
ci = mpc_add((cre, cim), mpc_log(z, wp), prec, rnd)
return ci
def mpi_mul(s, t, prec):
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:
cases = sorted(cases, cmp=mpf_cmp)
a = mpf_pos(cases[0], prec, round_floor)
b = mpf_pos(cases[-1], prec, round_ceiling)
return a, b
def mpi_mul(s, t, prec):
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(sb, 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:
cases = sorted(cases, cmp=mpf_cmp)
a = mpf_pos(cases[0], prec, round_floor)
b = mpf_pos(cases[-1], prec, round_ceiling)
return a, b
def mpf_ci(x, prec, rnd=round_fast):
if mpf_sign(x) < 0:
raise ComplexResult
return mpf_ci_si(x, prec, rnd, 0)[0]
def mpf_ci(x, prec, rnd=round_fast):
if mpf_sign(x) < 0:
raise ComplexResult
return mpf_ci_si(x, prec, rnd, 0)[0]
