def check_ulpdiff(self, exact, rounded):
# current precision
p = context.p.prec
# Convert infinities to the largest representable number + 1.
x = exact
if exact.is_infinite():
x = _dec_from_triple(exact._sign, '10', context.p.Emax)
y = rounded
if rounded.is_infinite():
y = _dec_from_triple(rounded._sign, '10', context.p.Emax)
# err = (rounded - exact) / ulp(rounded)
self.maxctx.prec = p * 2
t = self.maxctx.subtract(y, x)
if context.c.flags[C.Clamped] or \
context.c.flags[C.Underflow]:
# The standard ulp does not work in Underflow territory.
ulp = self.harrison_ulp(y)
else:
ulp = self.standard_ulp(y, p)
# Error in ulps.
err = self.maxctx.divide(t, ulp)
dir = self.rounding_direction(x, context.p.rounding)
if dir == 0:
if P.Decimal("-0.6") < err < P.Decimal("0.6"):
return True
elif dir == 1: # directed, upwards
if P.Decimal("-0.1") < err < P.Decimal("1.1"):
return True
elif dir == -1: # directed, downwards
if P.Decimal("-1.1") < err < P.Decimal("0.1"):
return True
else: # ROUND_05UP
if P.Decimal("-1.1") < err < P.Decimal("1.1"):
return True
print("ulp: %s error: %s exact: %s c_rounded: %s" %
(ulp, err, exact, rounded))
return False
def check_ulpdiff(self, exact, rounded):
# current precision
p = context.p.prec
# Convert infinities to the largest representable number + 1.
x = exact
if exact.is_infinite():
x = _dec_from_triple(exact._sign, '10', context.p.Emax)
y = rounded
if rounded.is_infinite():
y = _dec_from_triple(rounded._sign, '10', context.p.Emax)
# err = (rounded - exact) / ulp(rounded)
self.maxctx.prec = p * 2
t = self.maxctx.subtract(y, x)
if context.c.flags[C.Clamped] or \
context.c.flags[C.Underflow]:
# The standard ulp does not work in Underflow territory.
ulp = self.harrison_ulp(y)
else:
ulp = self.standard_ulp(y, p)
# Error in ulps.
err = self.maxctx.divide(t, ulp)
dir = self.rounding_direction(x, context.p.rounding)
if dir == 0:
if P.Decimal("-0.6") < err < P.Decimal("0.6"):
return True
elif dir == 1: # directed, upwards
if P.Decimal("-0.1") < err < P.Decimal("1.1"):
return True
elif dir == -1: # directed, downwards
if P.Decimal("-1.1") < err < P.Decimal("0.1"):
return True
else: # ROUND_05UP
if P.Decimal("-1.1") < err < P.Decimal("1.1"):
return True
print("ulp: %s error: %s exact: %s c_rounded: %s"
% (ulp, err, exact, rounded))
return False
def standard_ulp(self, dec, prec):
return _dec_from_triple(0, "1", dec._exp + len(dec._int) - prec)
def standard_ulp(self, dec, prec):
return _dec_from_triple(0, '1', dec._exp + len(dec._int) - prec)
def update_event(self, inp=-1):
self.set_output_val(0, _pydecimal._dec_from_triple(self.input(0), self.input(1), self.input(2), self.input(3)))
