def frexp(x):
"""
Version of frexp that works for numbers with uncertainty, and also
for regular numbers.
"""
# The code below is inspired by uncert_core.wrap(). It is
# simpler because only 1 argument is given, and there is no
# delegation to other functions involved (as for __mul__, etc.).
aff_func = to_affine_scalar(x)
if aff_func._linear_part:
(mantissa, exponent) = math.frexp(aff_func.nominal_value)
return (
AffineScalarFunc(
mantissa,
# With frexp(x) = (m, e), x = m*2**e, so m = x*2**-e
# and therefore dm/dx = 2**-e (as e in an integer that
# does not vary when x changes):
LinearCombination([2**-exponent, aff_func._linear_part])),
# The exponent is an integer and is supposed to be
# continuous (errors must be small):
exponent)
else:
# This function was not called with an AffineScalarFunc
# argument: there is no need to return numbers with uncertainties:
return math.frexp(x)
def rebin(self, x_rebin_fact, y_rebin_fact):
""" Rebin the data and adjust dims """
if self.data == None:
raise Exception('Please read in the file you wish to rebin first')
(mantis_x, exp_x) = math.frexp(x_rebin_fact)
(mantis_y, exp_y) = math.frexp(y_rebin_fact)
# FIXME - this is a floating point comparison, is it always exact?
if (mantis_x != 0.5 or mantis_y != 0.5):
raise Exception('Rebin factors not power of 2 not supported (yet)')
if int(self.dim1 / x_rebin_fact) * x_rebin_fact != self.dim1 or \
int(self.dim2 / x_rebin_fact) * x_rebin_fact != self.dim2 :
raise('image size is not divisible by rebin factor - ' + \
'skipping rebin')
pass ## self.data.savespace(1) # avoid the upcasting behaviour
i = 1
while i < x_rebin_fact:
# FIXME - why do you divide by 2? Rebinning should increase counts?
self.data = ((self.data[:, ::2] + self.data[:, 1::2]) / 2)
i = i * 2
i = 1
while i < y_rebin_fact:
self.data = ((self.data[::2, :] + self.data[1::2, :]) / 2)
i = i * 2
self.resetvals()
self.dim1 = self.dim1 / x_rebin_fact
self.dim2 = self.dim2 / y_rebin_fact
#update header
self.update_header()
def frexp(x):
"""
Version of frexp that works for numbers with uncertainty, and also
for regular numbers.
"""
# The code below is inspired by uncertainties.wrap(). It is
# simpler because only 1 argument is given, and there is no
# delegation to other functions involved (as for __mul__, etc.).
aff_func = to_affine_scalar(x)
if aff_func.derivatives:
result = math.frexp(aff_func.nominal_value)
# With frexp(x) = (m, e), dm/dx = 1/(2**e):
factor = 1/(2**result[1])
return (
AffineScalarFunc(
result[0],
# Chain rule:
dict([(var, factor*deriv)
for (var, deriv) in aff_func.derivatives.iteritems()])),
# The exponent is an integer and is supposed to be
# continuous (small errors):
result[1])
else:
# This function was not called with an AffineScalarFunc
# argument: there is no need to return numbers with uncertainties:
return math.frexp(x)
def _product(values):
"""Return product of values as (exponent, mantissa)."""
errmsg = 'mixed Decimal and float is not supported'
prod = 1
for x in values:
if isinstance(x, float):
break
prod *= x
else:
return (0, prod)
if isinstance(prod, Decimal):
raise TypeError(errmsg)
# Since floats can overflow easily, we calculate the product as a
# sort of poor-man's BigFloat. Given that:
#
# x = 2**p * m # p == power or exponent (scale), m = mantissa
#
# we can calculate the product of two (or more) x values as:
#
# x1*x2 = 2**p1*m1 * 2**p2*m2 = 2**(p1+p2)*(m1*m2)
#
mant, scale = 1, 0 #math.frexp(prod) # FIXME
for y in chain([x], values):
if isinstance(y, Decimal):
raise TypeError(errmsg)
m1, e1 = math.frexp(y)
m2, e2 = math.frexp(mant)
scale += (e1 + e2)
mant = m1*m2
return (scale, mant)
def nearly_equal(float1, float2, places=15):
"""
Determines whether two floating point numbers are nearly equal (to
within reasonable rounding errors
"""
mantissa1, exp1 = math.frexp(float1)
mantissa2, exp2 = math.frexp(float2)
return (round(mantissa1, places) == round(mantissa2, places) and
exp1 == exp2)
def __init__(self, L):
self.L = L
if math.frexp(self.L)[0]!=0.5:
print "profile size is not a power of 2"
pdb.set_trace()
self.J = math.frexp(self.L)[1]-1
self.data = False
self.value = dict()
def _not_nearly_equal(self, float1, float2):
"""
Determines whether two floating point numbers are nearly equal (to
within reasonable rounding errors
"""
mantissa1, exp1 = math.frexp(float1)
mantissa2, exp2 = math.frexp(float2)
return not ((round(mantissa1, self.nearly_equal_places) ==
round(mantissa2, self.nearly_equal_places)) and
exp1 == exp2)
def SetFog(self,fog):
projection = (fog.function >> 3) & 1
if projection:
if fog.z_far == fog.z_near or fog.z_end == fog.z_start:
A = 0
C = 0
else:
A = (fog.z_far - fog.z_near)/(fog.z_end - fog.z_start)
C = (fog.z_start - fog.z_near)/(fog.z_end - fog.z_start)
b_shift = 0
b_magnitude = 0
else:
if fog.z_far == fog.z_near or fog.z_end == fog.z_start:
A = 0
B = 0.5
C = 0
else:
A = fog.z_far*fog.z_near/((fog.z_far - fog.z_near)*(fog.z_end - fog.z_start))
B = fog.z_far/(fog.z_far - fog.z_near)
C = fog.z_start/(fog.z_end - fog.z_start)
if B > 1:
b_shift = 1 + int(ceil(log(B,2)))
elif 0 < B < 0.5:
b_shift = 0
else:
b_shift = 1
A /= 2**b_shift
b_magnitude = int(2*(B/2**b_shift)*8388638)
a_mantissa,a_exponent = frexp(A)
self.fog_param0[0:11] = int(abs(a_mantissa)*2**12) & 0x7FF
self.fog_param0[11:19] = a_exponent + 126 if A != 0 else 0
self.fog_param0[19] = a_mantissa < 0
self.fog_param1[0:24] = b_magnitude
self.fog_param2[0:5] = b_shift
c_mantissa,c_exponent = frexp(C)
self.fog_param3[0:11] = int(abs(c_mantissa)*2**12) & 0x7FF
self.fog_param3[11:19] = c_exponent + 126 if C != 0 else 0
self.fog_param3[19] = c_mantissa < 0
self.fog_param3[20:21] = projection
self.fog_param3[21:24] = fog.function
self.fog_color[0:8] = fog.color.b
self.fog_color[8:16] = fog.color.g
self.fog_color[16:24] = fog.color.r
def __new__(cls, *args):
if len(args) == 0:
self = bytes.__new__(cls)
self._pad = 0
elif len(args) == 1:
if isinstance(args[0], IntType):
self = bytes.__new__(cls, uitob(args[0]))
else:
self = bytes.__new__(cls, args[0])
self._pad = 0
elif len(args) == 2:
if isinstance(args[0], str):
arg = int(args[0], args[1])
m, e = math.frexp(args[1])
bpd = e - (1 if m == 0.5 else 0)
bitlen = len(args[0]) * bpd # num digits * bits per digit
shift = ((bitlen + 7) & ~7) - bitlen
self = bytes.__new__(cls, uitob(arg << shift))
self._pad = shift & 7
else:
self = bytes.__new__(cls, args[1])
self._pad = args[0]
if pad > 7 or (pad and not self):
raise ValueError('invalid pad value')
else:
raise TypeError('BitString constructor takes 1 or 2 args')
return self
def test_builtin_math_frexp(self):
import math
def fn(f):
return math.frexp(f)
res = self.interpret(fn, [10/3.0])
mantissa, exponent = math.frexp(10/3.0)
assert self.float_eq(res.item0, mantissa) and self.float_eq(res.item1, exponent)
def log2(x):
# Uses an algorithm that should:
# (a) produce exact results for powers of 2, and
# (b) be monotonic, assuming that the system log is monotonic.
if not isfinite(x):
if isnan(x):
return x # log2(nan) = nan
elif x > 0.0:
return x # log2(+inf) = +inf
else:
# log2(-inf) = nan, invalid-operation
raise ValueError("math domain error")
if x > 0.0:
if 0: # HAVE_LOG2
return math.log2(x)
m, e = math.frexp(x)
# We want log2(m * 2**e) == log(m) / log(2) + e. Care is needed when
# x is just greater than 1.0: in that case e is 1, log(m) is negative,
# and we get significant cancellation error from the addition of
# log(m) / log(2) to e. The slight rewrite of the expression below
# avoids this problem.
if x >= 1.0:
return math.log(2.0 * m) / math.log(2.0) + (e - 1)
else:
return math.log(m) / math.log(2.0) + e
else:
raise ValueError("math domain error")
def evaluate_func(next_func): if next_func[0] == 'x': return x elif next_func[0] == 'y': return y elif next_func[0] == 'abs': return abs(evaluate_func(next_func[1])) elif next_func[0] == 'cos_pi': return cos(pi*evaluate_func(next_func[1])) elif next_func[0] == 'sin_pi': return sin(pi*evaluate_func(next_func[1])) elif next_func[0] == 'sqrt': return sqrt(abs(pi*evaluate_func(next_func[1]))) elif next_func[0] == 'diff': return evaluate_func(next_func[1])-evaluate_func(next_func[2]) elif next_func[0] == 'ave': return (evaluate_func(next_func[1])+evaluate_func(next_func[2]))/2.0 elif next_func[0] == 'prod': return evaluate_func(next_func[1])*evaluate_func(next_func[2]) elif next_func[0] == 'frexp': return frexp(evaluate_func(next_func[1]))[0] elif next_func[0] == 'x': return evaluate_func(next_func[1]) elif next_func[0] == 'y': return evaluate_func(next_func[2])
def rank_sum_n_sites(measurements, details=False):
if math.frexp(len(measurements))[0] != 0.5:
print("rank_sum_n_sites received an input of length %s, which is not equal to the number of genotypes."
"Quitting." % len(measurements))
sys.exit()
output_indices = []
for genotype in measurements:
output_indices.append(measurements.keys().index(genotype))
done = False
while not done:
done = True
for i in range(len(measurements) - 1):
if ranksums(measurements[measurements.keys()[output_indices[i]]],
measurements[measurements.keys()[output_indices[i+1]]])[0] < 0:
output_indices[i], output_indices[i + 1] = output_indices[i + 1], output_indices[i]
done = False
output = []
output_look_good = []
number_loci = 0
for index in output_indices:
output.append(measurements.keys()[index])
if len(measurements.keys()[index]) > number_loci:
number_loci = len(measurements.keys()[index])
for index in output_indices:
output_look_good.append(genotype_look_good(measurements.keys()[index], number_loci))
output_detailed = []
for genotype in output:
fitness = measurements[genotype][1:]
output_detailed.append([genotype, np.mean(fitness)])
if not details:
return output
else:
return output_detailed
def R4_IEEE2VAX(fpValue, varName):
# type: (float, str) -> bytes
"""
Convert floating point value to VAR REAL*4 string
"""
try:
m, e = math.frexp(float(fpValue))
if m == 0.0:
intValue = 0
else:
sign = m < 0
exp = e + 128
mant = int((0x1000000 * (abs(m) - 0.5)) + 0.5)
while mant >= 0x800000:
exp += 1
mant = (mant>> 1) - 0x400000
if exp < 1:
intValue = 0
elif exp > 0xff:
raise Exception("Exponent too large to store as VAX F float for %s."
% varName)
else:
intValue = ((sign << 15)
| (exp << 7)
| ((mant & 0x007f0000) >> 16)
| ((mant & 0x0000ffff) << 16))
return int_to_bytes(intValue)
except:
print("VAX float F conversion error for %s value: %s"
% (varName, fpValue))
return b"\0\0\0\0"
def float_to_decimal(f):
"Convert a floating point number to a Decimal with no loss of information"
# Transform (exactly) a float to a mantissa (0.5 <= abs(m) < 1.0) and an
# exponent. Double the mantissa until it is an integer. Use the integer
# mantissa and exponent to compute an equivalent Decimal. If this cannot
# be done exactly, then retry with more precision.
try:
mantissa, exponent = math.frexp(f)
except OverflowError:
return decimal.Inf
while mantissa != int(mantissa):
mantissa *= 2.0
exponent -= 1
mantissa = int(mantissa)
oldcontext = decimal.getcontext()
decimal.setcontext(decimal.Context(traps=[decimal.Inexact]))
try:
while True:
try:
return mantissa * decimal.Decimal(2) ** exponent
except decimal.Inexact:
decimal.getcontext().prec += 1
finally:
decimal.setcontext(oldcontext)
def __call__(self, x):
if x == 0:
return 0, self.mink
import math
m, e = math.frexp(x)
k = max((e - self.bits, self.mink))
return int(m * 2 ** (e - k)), k
def encode_double(value):
assert isinstance(value, float)
abs_val = _math.fabs(value)
# Work around repr()'s propensity to use exponential format
# for doubles with really large or really small absolute values.
# This extra work is because XML-RPC explicitly DOES NOT support
# exponential format, just decimal digits separated by a single
# period.
if value and (abs_val < 0.0001):
# Scary magic for small numbers, split the float into it's
# mantissa and exponent components and use the exponent to
# guess reasonable format.
m, e = _math.frexp(abs_val)
decimal_places = int(e/-3) + 17 # Derived at by pure, old-fashon,
# trail and error.
if decimal_places > 109:
# "%.110f" causes an OverflowError.
min_value = "0." + "0"*108 + "1"
if abs_val < eval(min_value):
value = min_value
else:
value = "%1.109f" % value
value = value.rstrip('0')
else:
value = "%1.*f" % (decimal_places, value)
value = value.rstrip('0')
elif value and (abs_val > 99999999999999984.0):
value = "%.1f" % value
else:
value = repr(value)
return "<value><double>" + value + "</double></value>\n"
def _hash_float(space, v):
if not isfinite(v):
if isinf(v):
return HASH_INF if v > 0 else -HASH_INF
return HASH_NAN
m, e = math.frexp(v)
sign = 1
if m < 0:
sign = -1
m = -m
# process 28 bits at a time; this should work well both for binary
# and hexadecimal floating point.
x = r_uint(0)
while m:
x = ((x << 28) & HASH_MODULUS) | x >> (HASH_BITS - 28)
m *= 268435456.0 # 2**28
e -= 28
y = r_uint(m) # pull out integer part
m -= y
x += y
if x >= HASH_MODULUS:
x -= HASH_MODULUS
# adjust for the exponent; first reduce it modulo HASH_BITS
e = e % HASH_BITS if e >= 0 else HASH_BITS - 1 - ((-1 - e) % HASH_BITS)
x = ((x << e) & HASH_MODULUS) | x >> (HASH_BITS - e)
x = intmask(intmask(x) * sign)
return -2 if x == -1 else x
def float2decimal(fval):
""" Convert a floating point number to a Decimal with no loss of
information
"""
# Transform (exactly) a float to a mantissa (0.5 <= abs(m) < 1.0) and an
# exponent. Double the mantissa until it is an integer. Use the integer
# mantissa and exponent to compute an equivalent Decimal. If this cannot
# be done exactly, then retry with more precision.
#
# This routine is from
# http://docs.python.org/release/2.5.2/lib/decimal-faq.html
mantissa, exponent = math.frexp(fval)
try:
while mantissa != int(mantissa):
mantissa *= 2.0
exponent -= 1
mantissa = int(mantissa)
except (OverflowError, ValueError):
return "---"
oldcontext = decimal.getcontext()
decimal.setcontext(decimal.Context(traps=[decimal.Inexact]))
try:
while True:
try:
return mantissa * decimal.Decimal(2) ** exponent
except decimal.Inexact:
decimal.getcontext().prec += 1
finally:
decimal.setcontext(oldcontext)
def naturallog(x):
mantissa , exponent = math.frexp(x)
ln2 = 0.693147180559945309417
answer = 0
for i in range (1,40):
answer += -(-1)**i * ((mantissa - 1)**i/i)
return(answer + exponent * ln2)
def PyNextAfter(x, y):
"""returns the next float after x in the direction of y if possible, else returns x"""
# if x or y is Nan, we don't do much
if IsNaN(x) or IsNaN(y):
return x
# we can't progress if x == y
if x == y:
return x
# similarly if x is infinity
if x >= infinity or x <= -infinity:
return x
# return small numbers for x very close to 0.0
if -minFloat < x < minFloat:
if y > x:
return x + smallEpsilon
else:
return x - smallEpsilon # we know x != y
# it looks like we have a normalized number
# break x down into a mantissa and exponent
m, e = math.frexp(x)
# all the special cases have been handled
if y > x:
m += epsilon
else:
m -= epsilon
return math.ldexp(m, e)
def _write_float(f, x): import math if x < 0: sign = 0x8000 x = x * -1 else: sign = 0 if x == 0: expon = 0 himant = 0 lomant = 0 else: fmant, expon = math.frexp(x) if expon > 16384 or fmant >= 1: # Infinity or NaN expon = sign|0x7FFF himant = 0 lomant = 0 else: # Finite expon = expon + 16382 if expon < 0: # denormalized fmant = math.ldexp(fmant, expon) expon = 0 expon = expon | sign fmant = math.ldexp(fmant, 32) fsmant = math.floor(fmant) himant = long(fsmant) fmant = math.ldexp(fmant - fsmant, 32) fsmant = math.floor(fmant) lomant = long(fsmant) _write_short(f, expon) _write_long(f, himant) _write_long(f, lomant)
def descr_hex(self, space):
TOHEX_NBITS = rfloat.DBL_MANT_DIG + 3 - (rfloat.DBL_MANT_DIG + 2) % 4
value = self.floatval
if not isfinite(value):
return self.descr_str(space)
if value == 0.0:
if copysign(1., value) == -1.:
return space.wrap("-0x0.0p+0")
else:
return space.wrap("0x0.0p+0")
mant, exp = math.frexp(value)
shift = 1 - max(rfloat.DBL_MIN_EXP - exp, 0)
mant = math.ldexp(mant, shift)
mant = abs(mant)
exp -= shift
result = ['\0'] * ((TOHEX_NBITS - 1) // 4 + 2)
result[0] = _char_from_hex(int(mant))
mant -= int(mant)
result[1] = "."
for i in range((TOHEX_NBITS - 1) // 4):
mant *= 16.0
result[i + 2] = _char_from_hex(int(mant))
mant -= int(mant)
if exp < 0:
sign = "-"
else:
sign = "+"
exp = abs(exp)
s = ''.join(result)
if value < 0.0:
return space.wrap("-0x%sp%s%d" % (s, sign, exp))
else:
return space.wrap("0x%sp%s%d" % (s, sign, exp))
def as_integer_ratio(self, a, **args):
"""Convert real number to a (numer, denom) pair. """
v, n = math.frexp(a) # XXX: hack, will work only for floats
for i in xrange(300):
if v != math.floor(v):
v, n = 2*v, n - 1
else:
break
numer, denom = int(v), 1
m = 1 << abs(n)
if n > 0:
numer *= m
else:
denom = m
n, d = self.limit_denom(numer, denom, **args)
if a and not n:
return numer, denom
else:
return n, d
def set_ref(self, refval):
x = self.teach()
m,e = math.frexp(refval / 5e-9)
if m < 0:
s = 0x80
m = -m
else:
s = 0
m = math.ldexp(m, -1)
for i in range(14,20):
m = math.ldexp(m, 8)
h = int(m)
m -= h
x[i] = s | h
s = 0
e -= 31
if e < 0:
e += 256
x[20] = e
y=bytearray("LN")
for i in x:
if i == 10 or i == 27 or i == 13 or i == 43:
y.append(27)
y.append(i)
d.wr(y)
def _bus_message_received_cb(self, bus, message):
"""
@param bus: the message bus sending the message
@param message: the message received
"""
if message.get_structure().get_name() == 'level':
s = message.get_structure()
peak = list(s['peak'])
decay = list(s['decay'])
rms = list(s['rms'])
for l in peak, decay, rms:
for index, v in enumerate(l):
try:
v = frexp(v)
except (SystemError, OverflowError, ValueError):
# It was an invalid value (e.g. -Inf), so clamp to
# something appropriate
l[index] = -100.0
if not self.uiState:
self.warning("effect %s doesn't have a uiState" %
self.name)
else:
for k, v in ('peak', peak), ('decay', decay), ('rms', rms):
self.uiState.set('volume-%s' % k, v)
if not self.firstVolumeValueReceived:
self.uiState.set('volume-volume', self.effect_getVolume())
self.firstVolumeValueReceived = True
def msum(iterable):
"""Full precision summation. Compute sum(iterable) without any
intermediate accumulation of error. Based on the 'lsum' function
at http://code.activestate.com/recipes/393090/
"""
tmant, texp = 0, 0
for x in iterable:
mant, exp = math.frexp(x)
mant, exp = int(math.ldexp(mant, mant_dig)), exp - mant_dig
if texp > exp:
tmant <<= texp-exp
texp = exp
else:
mant <<= exp-texp
tmant += mant
# Round tmant * 2**texp to a float. The original recipe
# used float(str(tmant)) * 2.0**texp for this, but that's
# a little unsafe because str -> float conversion can't be
# relied upon to do correct rounding on all platforms.
tail = max(len(bin(abs(tmant)))-2 - mant_dig, etiny - texp)
if tail > 0:
h = 1 << (tail-1)
tmant = tmant // (2*h) + bool(tmant & h and tmant & 3*h-1)
texp += tail
return math.ldexp(tmant, texp)
def _write_float(f, x):
import math
if x < 0:
sign = 32768
x = x * -1
else:
sign = 0
if x == 0:
expon = 0
himant = 0
lomant = 0
else:
fmant, expon = math.frexp(x)
if expon > 16384 or fmant >= 1 or fmant != fmant:
expon = sign | 32767
himant = 0
lomant = 0
else:
expon = expon + 16382
if expon < 0:
fmant = math.ldexp(fmant, expon)
expon = 0
expon = expon | sign
fmant = math.ldexp(fmant, 32)
fsmant = math.floor(fmant)
himant = long(fsmant)
fmant = math.ldexp(fmant - fsmant, 32)
fsmant = math.floor(fmant)
lomant = long(fsmant)
_write_ushort(f, expon)
_write_ulong(f, himant)
_write_ulong(f, lomant)
def get01(self, x):
m, e = math.frexp(self._base - x)
if m >= 0 and e <= _E_MAX:
v = (e + m) / (2. * _E_MAX)
return 1 - v
else:
return 1 if m < 0 else 0
def get01(self, x):
m, e = math.frexp(x - self._base)
if m >= 0 and e <= _E_MAX:
v = (e + m) / (2. * _E_MAX)
return v
else:
return 0 if m < 0 else 1
print(math.factorial(6)) print(math.factorial(12)) # Round a number downward to its nearest integer print(math.floor(1.4)) print(math.floor(5.3)) print(math.floor(-5.3)) print(math.floor(22.6)) # Return the remainder after modulo operation print(math.fmod(67, 7)) print(math.fmod(17, 4)) print(math.fmod(16, 4)) #Return mantissa and exponent of a given number print(math.frexp(4)) print(math.frexp(7.9)) # Print the sum of all items print(math.fsum((1, 2, 3, 4, 5))) #find the highest number that can divide two numbers print(math.gcd(26, 12)) print(math.gcd(12, 6)) print(math.gcd(10, 0)) print(math.gcd(0, 34)) print(math.gcd(0, 0)) #compare the closeness of two values print(math.isclose(1.233, 1.4566)) print(math.isclose(1.233, 1.233))
def t_math(n1):
nf = math.ceil(n1)
ng = math.floor(n1)
nh = math.frexp(n1)
print 'ceil:%s,floor:%s,frexp:%s' % (nf, ng, nh)
def __floor__(self):
return 'floor'
assert math.trunc(A()) == 'trunc'
assert math.ceil(A()) == 'ceil'
assert math.floor(A()) == 'floor'
with assertRaises(TypeError):
math.trunc(object())
with assertRaises(TypeError):
math.ceil(object())
with assertRaises(TypeError):
math.floor(object())
assert str(math.frexp(0.0)) == str((+0.0, 0))
assert str(math.frexp(-0.0)) == str((-0.0, 0))
assert math.frexp(1) == (0.5, 1)
assert math.frexp(1.5) == (0.75, 1)
assert math.frexp(float('inf')) == (float('inf'), 0)
assert str(math.frexp(float('nan'))) == str((float('nan'), 0))
assert_raises(TypeError, lambda: math.frexp(None))
assert math.gcd(0, 0) == 0
assert math.gcd(1, 0) == 1
assert math.gcd(0, 1) == 1
assert math.gcd(1, 1) == 1
assert math.gcd(-1, 1) == 1
assert math.gcd(1, -1) == 1
assert math.gcd(-1, -1) == 1
def floor_log(x):
return math.frexp(x)[1] - 1
def quantize_scale(scale):
significand, shift = math.frexp(scale)
significand_q31 = round(significand * (1 << 31))
return significand_q31, shift
def frexp(x):
return math.frexp(x)
def neon_math_frexp(self):
x = self.stack.pop().value
(m, e) = math.frexp(float(x))
self.stack.append(Value(decimal.Decimal(e)))
self.stack.append(Value(decimal.Decimal(m)))
import math
print(dir(math))
print(math.ceil(-1))
print(math.ceil(1.024))
print(math.copysign(1, -1))
print(math.fabs(-1))
print(math.factorial(5))
print(math.floor(-1.024))
print(math.floor(1.024))
print(math.fmod(1, 2))
print(math.frexp(1024))
print(math.fsum([1, 2, 3, 4, 5, 6, 7, 8]))
print(math.gcd(3, 9))
print(math.exp(3))
print(math.expm1(3))
print(math.log(10, 24))
print(math.log1p(1024))
print(math.log2(1024))
print(math.log(10))
print(math.log10(100))
print(math.pow(3, 3))
print(math.sqrt(81))
print('------------------------')
def fn(x):
res = frexp(x)
return res[0] + float(res[1])
assertEqual(math.fmod(-3.0, INF), -3.0)
assertEqual(math.fmod(3.0, NINF), 3.0)
assertEqual(math.fmod(-3.0, NINF), -3.0)
assertEqual(math.fmod(0.0, 3.0), 0.0)
assertEqual(math.fmod(0.0, NINF), 0.0)
doc="Frexp"
assertRaises(TypeError, math.frexp)
def testfrexp(name, result, expected):
(mant, exp), (emant, eexp) = result, expected
if abs(mant-emant) > eps or exp != eexp:
fail('%s returned %r, expected %r'%\
(name, result, expected))
testfrexp('frexp(-1)', math.frexp(-1), (-0.5, 1))
testfrexp('frexp(0)', math.frexp(0), (0, 0))
testfrexp('frexp(1)', math.frexp(1), (0.5, 1))
testfrexp('frexp(2)', math.frexp(2), (0.5, 2))
assertEqual(math.frexp(INF)[0], INF)
assertEqual(math.frexp(NINF)[0], NINF)
assertTrue(math.isnan(math.frexp(NAN)[0]))
doc="Fsum"
# math.fsum relies on exact rounding for correct operation.
# There's a known problem with IA32 floating-point that causes
# inexact rounding in some situations, and will cause the
# math.fsum tests below to fail; see issue #2937. On non IEEE
# 754 platforms, and on IEEE 754 platforms that exhibit the
# problem described in issue #2937, we simply skip the whole
def frexp(self):
import math
return AdvTuple(math.frexp(self))
def test_frexp(self):
self.assertRaises(TypeError, math.frexp)
def testfrexp(name, result, expected):
(mant, exp), (emant, eexp) = result, expected
if abs(mant - emant) > eps or exp != eexp:
self.fail('%s returned %r, expected %r'%\
(name, result, expected))
testfrexp('frexp(-1)', math.frexp(-1), (-0.5, 1))
testfrexp('frexp(0)', math.frexp(0), (0, 0))
testfrexp('frexp(1)', math.frexp(1), (0.5, 1))
testfrexp('frexp(2)', math.frexp(2), (0.5, 2))
self.assertEqual(math.frexp(INF)[0], INF)
self.assertEqual(math.frexp(NINF)[0], NINF)
self.assertTrue(math.isnan(math.frexp(NAN)[0]))
testfrexp('frexp(True)', math.frexp(True), (0.5, 1))
testfrexp('frexp(False)', math.frexp(False), (0.0, 0))
testfrexp('frexp(6227020800)', math.frexp(6227020800),
(0.7249206304550171, 33))
testfrexp('frexp(2432902008176640000999)',
math.frexp(2432902008176640000999), (0.5151870395916913, 72))
self.assertRaises(TypeError, math.frexp, 'hello')
class X(int):
def getX():
return 'Ahoj'
class Y(float):
def getY():
return 'Ahoj'
testfrexp('frexp(X(10))', math.frexp(X(10)), (0.625, 4))
testfrexp('frexp(Y(11.11))', math.frexp(Y(11.11)), (0.694375, 4))
print 'fmod'
testit('fmod(10,1)', math.fmod(10,1), 0)
testit('fmod(10,0.5)', math.fmod(10,0.5), 0)
testit('fmod(10,1.5)', math.fmod(10,1.5), 1)
testit('fmod(-10,1)', math.fmod(-10,1), 0)
testit('fmod(-10,0.5)', math.fmod(-10,0.5), 0)
testit('fmod(-10,1.5)', math.fmod(-10,1.5), -1)
print 'frexp'
def testfrexp(name, (mant, exp), (emant, eexp)):
if abs(mant-emant) > eps or exp != eexp:
raise TestFailed, '%s returned %s, expected %s'%\
(name, `mant, exp`, `emant,eexp`)
testfrexp('frexp(-1)', math.frexp(-1), (-0.5, 1))
testfrexp('frexp(0)', math.frexp(0), (0, 0))
testfrexp('frexp(1)', math.frexp(1), (0.5, 1))
testfrexp('frexp(2)', math.frexp(2), (0.5, 2))
print 'hypot'
testit('hypot(0,0)', math.hypot(0,0), 0)
testit('hypot(3,4)', math.hypot(3,4), 5)
print 'ldexp'
testit('ldexp(0,1)', math.ldexp(0,1), 0)
testit('ldexp(1,1)', math.ldexp(1,1), 2)
testit('ldexp(1,-1)', math.ldexp(1,-1), 0.5)
testit('ldexp(-1,1)', math.ldexp(-1,1), -2)
print 'log'
# constant to be used when iterating with range() over all considered quantum effects
# (range() is exclusive with respect to the last element)
S_LAST_INDEX = 1
# construction of aCLIMAX constant which is used to evaluate mean square displacement (u)
with warnings.catch_warnings(record=True) as warning_list:
warnings.simplefilter("always")
H_BAR = constants.codata.value(
"Planck constant over 2 pi"
) # H_BAR = 1.0545718e-34 [J s] = [kg m^2 / s ]
if len(warning_list) >= 1 and isinstance(warning_list[0].message,
ConstantWarning):
H_BAR = constants.hbar # H_BAR = 1.0545718e-34 [J s] = [kg m^2 / s ]
H_BAR_DECOMPOSITION = math.frexp(H_BAR)
M2_TO_ANGSTROM2 = 1.0 / constants.angstrom**2 # m^2 = 10^20 A^2
M2_TO_ANGSTROM2_DECOMPOSITION = math.frexp(M2_TO_ANGSTROM2)
KG2AMU = constants.codata.value(
"kilogram-atomic mass unit relationship") # kg = 6.022140857e+26 amu
KG2AMU_DECOMPOSITION = math.frexp(KG2AMU)
# here we divide by 100 because we need relation between hertz and inverse cm
HZ2INV_CM = constants.codata.value(
"hertz-inverse meter relationship"
) / 100 # Hz [s^1] = 3.33564095198152e-11 [cm^-1]
HZ2INV_CM_DECOMPOSITION = math.frexp(HZ2INV_CM)
# Conversion factor from VASP internal units
import math
pow(3, 2)
for i in range(1, 11):
print(pow(i, 2)) # for print the square of first 10 numbers
print(pow(i, 3)) # for print the cube of first 10 numbers
print(pow(i, 0.5)) # for print the square root of first 10 numbers
lst = [11, 32, 34, 54, 67, 87, 24, 55, 36, 87]
max(lst) # returns the maximum numbers
min(lst) # returns the minimum numbers
math.ceil(5) # ceil and floor numbers
math.copysign(5, -1) # copy the sign of y
math.factorial(5) # returns the factorial of the numbers
math.fmod(40, 6) # returns the remainder
math.frexp(5) # returns the exponent of x as the pair of (m,e)
math.sum(lst) # returns the sum of the values present
math.exp(5) # returns the exponent of (e,5)
math.expm1(6) # returns the value of e**x-1
math.sqrt(5) # returns the square root of x
math.gcd(46, 84) # returns the greatest common divisor
math.lcm(25, 20) # returns the least common multiple
math.nextafter(
34, 36
) # returns the next number in floting point either towards zero/opposite
math.prod(lst) # returns the product of all availale iterables
math.remainder(6, 5) # returns the reaminder
assert d == {'a': 1, 'b': 2.1}
assert type(d['a']) == int
assert type(d['b']) == float
# issue 203
def f(z):
z += 1
return z
x = 1.0
assert x != f(x)
# issue 204
import math
m, e = math.frexp(abs(123.456))
assert m == 0.9645
assert m * (1 << 24) == 16181624.832
# issue 207
for x in range(0x7ffffff0, 0x8000000f):
assert x & x == x, "%s & %s == %s" % (hex(x), hex(x), hex(x & x))
assert x | x == x, "%s | %s == %s" % (hex(x), hex(x), hex(x | x))
for x in range(0x17ffffff0, 0x17fffffff):
assert x & x == x, "%s & %s == %s" % (hex(x), hex(x), hex(x & x))
assert x | x == x, "%s | %s == %s" % (hex(x), hex(x), hex(x | x))
# issue 208
a=5
def test_frexp(self, space):
w_res = space.execute("return Math.frexp(1234)")
assert self.unwrap(space, w_res) == [math.frexp(1234)[0], 11]
def round_double(value, ndigits, half_even=False):
"""Round a float half away from zero.
Specify half_even=True to round half even instead.
The argument 'value' must be a finite number. This
function may return an infinite number in case of
overflow (only if ndigits is a very negative integer).
"""
if ndigits == 0:
# fast path for this common case
if half_even:
return round_half_even(value)
else:
return round_away(value)
if value == 0.0:
return 0.0
# The basic idea is very simple: convert and round the double to
# a decimal string using _Py_dg_dtoa, then convert that decimal
# string back to a double with _Py_dg_strtod. There's one minor
# difficulty: Python 2.x expects round to do
# round-half-away-from-zero, while _Py_dg_dtoa does
# round-half-to-even. So we need some way to detect and correct
# the halfway cases.
# a halfway value has the form k * 0.5 * 10**-ndigits for some
# odd integer k. Or in other words, a rational number x is
# exactly halfway between two multiples of 10**-ndigits if its
# 2-valuation is exactly -ndigits-1 and its 5-valuation is at
# least -ndigits. For ndigits >= 0 the latter condition is
# automatically satisfied for a binary float x, since any such
# float has nonnegative 5-valuation. For 0 > ndigits >= -22, x
# needs to be an integral multiple of 5**-ndigits; we can check
# this using fmod. For -22 > ndigits, there are no halfway
# cases: 5**23 takes 54 bits to represent exactly, so any odd
# multiple of 0.5 * 10**n for n >= 23 takes at least 54 bits of
# precision to represent exactly.
sign = copysign(1.0, value)
value = abs(value)
# find 2-valuation value
m, expo = math.frexp(value)
while m != math.floor(m):
m *= 2.0
expo -= 1
# determine whether this is a halfway case.
halfway_case = 0
if not half_even and expo == -ndigits - 1:
if ndigits >= 0:
halfway_case = 1
elif ndigits >= -22:
# 22 is the largest k such that 5**k is exactly
# representable as a double
five_pow = 1.0
for i in range(-ndigits):
five_pow *= 5.0
if math.fmod(value, five_pow) == 0.0:
halfway_case = 1
# round to a decimal string; use an extra place for halfway case
strvalue = formatd(value, 'f', ndigits + halfway_case)
if not half_even and halfway_case:
buf = [c for c in strvalue]
if ndigits >= 0:
endpos = len(buf) - 1
else:
endpos = len(buf) + ndigits
# Sanity checks: there should be exactly ndigits+1 places
# following the decimal point, and the last digit in the
# buffer should be a '5'
if not objectmodel.we_are_translated():
assert buf[endpos] == '5'
if '.' in buf:
assert endpos == len(buf) - 1
assert buf.index('.') == len(buf) - ndigits - 2
# increment and shift right at the same time
i = endpos - 1
carry = 1
while i >= 0:
digit = ord(buf[i])
if digit == ord('.'):
buf[i + 1] = chr(digit)
i -= 1
digit = ord(buf[i])
carry += digit - ord('0')
buf[i + 1] = chr(carry % 10 + ord('0'))
carry /= 10
i -= 1
buf[0] = chr(carry + ord('0'))
if ndigits < 0:
buf.append('0')
strvalue = ''.join(buf)
return sign * rstring_to_float(strvalue)
def compare_floats(v, val):
from math import frexp
vm, ve = frexp(val)
scale = 2.0**(-ve)
delta = abs(v * scale - val * scale)
return delta < 1.e-14
import math
# Sign Manipulation
print(math.copysign(
-2, -1)) # Copy the sign of the second arg to the first and return it.
print(math.fabs(-2)) # Return the absolute value
# Sequences
print(math.factorial(5)) # Return the value of !5
# Working with Floats
print(math.frexp(5))
print(math.ldexp(.625, 3))
print(sum([.1] * 10)) # Precision limited to 16 decimal points.
print(math.fsum([.1] * 10)) # Accurately sum floats to infinite precision
# Modulus
print(math.fmod(-1e-100, 1e100)) # Accurate modulus for working with floats
print(math.modf(5.123456))
print(math.remainder(37.123, 7))
print(37.123 % 7)
# Factoring
print(math.gcd(35, 3500), math.gcd(42, 2996))
# Testing for numeric attributes
print(math.isfinite(math.inf))
print(math.isfinite(0.0))
print(math.isinf(math.inf))
print(math.isnan(float('nan')))
print(
def quantize_scale(scale):
multiplier, shift = math.frexp(scale)
multiplier_q31 = round(multiplier * (1 << 31))
return multiplier_q31, shift
TEST_VALUES.append( rand )
for t in sorted(TEST_VALUES):
print fmt.format(t, int(t), math.trunc(t), math.floor(t), math.ceil(t) )
print
## 5.4.4 Alternate Representations
# modf separates the number into a (portion, whole)
for i in xrange(6):
print '{}/2 = {}'.format(i, math.modf(i/2.0))
print
# frexp(x) returns (m, e), where x = m + 2**e
print ' '.join(['{:^7}'] * 3).format('x','m','e')
print ' '.join(['{:-^7}'] * 3).format('','','')
for x in [0.1, 0.5, 4.0]:
m,e = math.frexp(x)
print '{:7.2f} {:7.2f} {:7d}'.format( x, m, e )
# ldexp(m,e) returns x, where x = m + 2**e
print ' '.join(['{:^7}'] * 3).format('m','e','x')
print ' '.join(['{:-^7}'] * 3).format('','','')
for m,e in [ (0.8, -3), (0.5, 0), (0.5, 3) ]:
x = math.ldexp(m, e)
print '{:7.2f} {:7d} {:7.2f}'.format( m, e, x )
print
## 5.4.5 Positive and Negative Signs
print math.fabs(-1.1)
print math.fabs(-0.0)
print math.fabs( 0.0)
print math.fabs( 1.1)
def frexp(x):
if isinstance(x, LineValue): lx = x.get_value()
else: lx = x
if lx == NAN: return LineValue(NAN)
return LineValue(math.frexp(lx))
def solve_control(density,
velocity,
target,
remaining_time,
level_control=False,
velocity_generator=multi_scale_control_cnn_16_2):
rank = spatial_rank(density)
size = int(max(density.shape[1:]))
# Create density grids
density_grids = [to_dipole_format(density)]
target_grids = [to_dipole_format(target)]
velocity_grids = [velocity]
for i in range(pymath.frexp(float(size))[1] - 1): # downsample until 1x1
density_grids.insert(0, moment_downsample2x(density_grids[0],
sum=True))
target_grids.insert(0, moment_downsample2x(target_grids[0], sum=True))
velocity_grids.insert(0, downsample2x(velocity_grids[0]))
added_velocity = None
level_scalings = []
velocities_by_level = []
for i in range(len(density_grids)):
density_grid = density_grids[i]
target_grid = target_grids[i]
velocity_grid = velocity_grids[i]
if added_velocity is None:
combined_velocity = velocity_grid
else:
added_velocity = upsample2x(added_velocity)[:, 2:-2, 2:-2, :]
combined_velocity = velocity_grid + added_velocity
# Add border pixel for smooth upsampling at the edges
padded_density = tf.pad(density_grid,
[[0, 0]] + [[1, 1]] * rank + [[0, 0]])
padded_target = tf.pad(target_grid,
[[0, 0]] + [[1, 1]] * rank + [[0, 0]])
padded_velocity = tf.pad(combined_velocity,
[[0, 0]] + [[1, 1]] * rank + [[0, 0]])
if added_velocity is not None:
added_velocity = tf.pad(added_velocity,
[[0, 0]] + [[1, 1]] * rank + [[0, 0]],
mode="SYMMETRIC")
added_velocity_lvl = velocity_generator(padded_density,
padded_velocity, padded_target,
remaining_time, i)
velocities_by_level.append(added_velocity_lvl)
level_scaling = create_level_scaling(level_control, i)
level_scalings.append(level_scaling)
if added_velocity is None:
added_velocity = added_velocity_lvl * level_scaling
else:
added_velocity += added_velocity_lvl * level_scaling
return added_velocity[:, 1:-1,
1:-1, :], (level_scalings, velocities_by_level)
#Урок номер 6 по модулю Math
import math
print("Длина строки", len("123"))
print("Округление", round(8.6))
print("Число ПИ", math.pi)
print("Число эллера", math.e)
print("Возведение в степень", math.pow(2, 3)) # 2**3
print("Остаток от деления", math.fmod(7, 3)) # 7%3
x = 5
print("Проверка на число", math.isfinite(x))
print("Проверка на бесконечность", math.isinf(x))
print("Мантисса и экспонента", math.frexp(123.456))
print("Квадратный корень", math.sqrt(9))
print("Модуль", math.fabs(-20))
print("Модуль числа 1, со знаком числа 2", math.copysign(-10, 5))
print("Отделяет целую часть и дробную", math.modf(123.456))
print("Округление в большую", math.ceil(4.1))
print("Округление в меньшую", math.floor(4.9))
print("Отбрасывание дробной части", math.trunc(8.9))
print("Отбрасывание дробной части", math.trunc(8.9))
print("Косинус угла", math.cos(math.radians(60)))
print("Синус угла", math.sin(math.radians(30)))
print("Тангенс угла", math.tan(math.radians(45)))
print("Гипотенуза", math.hypot(3, 4))
print("Логaрифм", math.log(8, 2))
print("Логaрифм десятичный", math.log10(100))
input()
def entry_point(argv):
m, e = math.frexp(0)
x, y = math.frexp(0)
print m, x
return 0
class FixedPoint:
# the exact value is self.n / 10**self.p;
# self.n is a long; self.p is an int
def __init__(self, value=0, precision=DEFAULT_PRECISION):
self.n = self.p = 0
self.set_precision(precision)
p = self.p
if isinstance(value, type("42.3e5")):
n, exp = _string2exact(value)
# exact value is n*10**exp = n*10**(exp+p)/10**p
effective_exp = exp + p
if effective_exp > 0:
n = n * _tento(effective_exp)
elif effective_exp < 0:
n = _roundquotient(n, _tento(-effective_exp))
self.n = n
return
if isinstance(value, type(42)) or isinstance(value, type(42L)):
self.n = long(value) * _tento(p)
return
if isinstance(value, FixedPoint):
temp = value.copy()
temp.set_precision(p)
self.n, self.p = temp.n, temp.p
return
if isinstance(value, type(42.0)):
# XXX ignoring infinities and NaNs and overflows for now
import math
f, e = math.frexp(abs(value))
assert f == 0 or 0.5 <= f < 1.0
# |value| = f * 2**e exactly
# Suck up CHUNK bits at a time; 28 is enough so that we suck
# up all bits in 2 iterations for all known binary double-
# precision formats, and small enough to fit in an int.
CHUNK = 28
top = 0L
# invariant: |value| = (top + f) * 2**e exactly
while f:
f = math.ldexp(f, CHUNK)
digit = int(f)
assert digit >> CHUNK == 0
top = (top << CHUNK) | digit
f = f - digit
assert 0.0 <= f < 1.0
e = e - CHUNK
# now |value| = top * 2**e exactly
# want n such that n / 10**p = top * 2**e, or
# n = top * 10**p * 2**e
top = top * _tento(p)
if e >= 0:
n = top << e
else:
n = _roundquotient(top, 1L << -e)
if value < 0:
n = -n
self.n = n
return
if isinstance(value, type(42 - 42j)):
raise TypeError("can't convert complex to FixedPoint: " +
` value `)
# can we coerce to a float?
yes = 1
try:
asfloat = float(value)
except:
yes = 0
if yes:
self.__init__(asfloat, p)
return
# similarly for long
yes = 1
try:
aslong = long(value)
except:
yes = 0
if yes:
self.__init__(aslong, p)
return
raise TypeError("can't convert to FixedPoint: " + ` value `)
# 25
# Return True if the values a and b are close to each other and False otherwise.
math.isclose(1.000000002, 1.000000001)
# True
math.isclose(1.000000003, 1.000000001)
# False
# base-2 logarithm of x
x = 2
# -> float
math.log(x, 2.0) # slow
math.log2(x)
# 1.0
# -> int
math.frexp(x)[1] - 1 # fast
x.bit_length() - 1 # faster
# 1
# decimal: accurate decimal math, eg: for money
from decimal import Decimal
sum(0.1 for i in range(1000))
# 99.9999999999986
sum(Decimal('0.1') for i in range(1000))
# Decimal('100.0')
Decimal(0.1) # be careful converting from floats!
# Decimal('0.1000000000000000055511151231257827021181583404541015625')
def digits(n: int) -> Generator[int, None, None]:
# How to get the digits of an integer
def compare_floats(v, val): vm, ve = math.frexp(val) scale = 2.0**(-ve) delta = abs(v*scale - val*scale) return delta < 1.e-14
def method_frexp(self, space, value):
mant, exp = math.frexp(value)
w_mant = space.newfloat(mant)
w_exp = space.newint(exp)
return space.newarray([w_mant, w_exp])
