def test_gcd_terms():
f = 2*(x + 1)*(x + 4)/(5*x**2 + 5) + (2*x + 2)*(x + 5)/(x**2 + 1)/5 + (2*x + 2)*(x + 6)/(5*x**2 + 5)
assert _gcd_terms(f) == ((S(6)/5)*((1 + x)/(1 + x**2)), 5 + x, 1)
assert _gcd_terms(Add.make_args(f)) == ((S(6)/5)*((1 + x)/(1 + x**2)), 5 + x, 1)
assert gcd_terms(f) == (S(6)/5)*((1 + x)*(5 + x)/(1 + x**2))
assert gcd_terms(Add.make_args(f)) == (S(6)/5)*((1 + x)*(5 + x)/(1 + x**2))
assert gcd_terms((2*x + 2)**3 + (2*x + 2)**2) == 4*(x + 1)**2*(2*x + 3)
assert gcd_terms(0) == 0
assert gcd_terms(1) == 1
assert gcd_terms(x) == x
assert gcd_terms(2 + 2*x) == Mul(2, 1 + x, evaluate=False)
arg = x*(2*x + 4*y)
garg = 2*x*(x + 2*y)
assert gcd_terms(arg) == garg
assert gcd_terms(sin(arg)) == sin(garg)
# issue 3040-like
alpha, alpha1, alpha2, alpha3 = symbols('alpha:4')
a = alpha**2 - alpha*x**2 + alpha + x**3 - x*(alpha + 1)
rep = (alpha, (1 + sqrt(5))/2 + alpha1*x + alpha2*x**2 + alpha3*x**3)
s = (a/(x - alpha)).subs(*rep).series(x, 0, 1)
assert simplify(collect(s, x)) == -sqrt(5)/2 - S(3)/2 + O(x)
def test_gcd_terms():
f = 2*(x + 1)*(x + 4)/(5*x**2 + 5) + (2*x + 2)*(x + 5)/(x**2 + 1)/5 + (2*x + 2)*(x + 6)/(5*x**2 + 5)
assert _gcd_terms(f) == ((S(6)/5)*((1 + x)/(1 + x**2)), 5 + x, 1)
assert _gcd_terms(Add.make_args(f)) == ((S(6)/5)*((1 + x)/(1 + x**2)), 5 + x, 1)
assert gcd_terms(f) == (S(6)/5)*((1 + x)*(5 + x)/(1 + x**2))
assert gcd_terms(Add.make_args(f)) == (S(6)/5)*((1 + x)*(5 + x)/(1 + x**2))
assert gcd_terms((2*x + 2)**3 + (2*x + 2)**2) == 4*(x + 1)**2*(2*x + 3)
assert gcd_terms(0) == 0
assert gcd_terms(1) == 1
assert gcd_terms(x) == x
assert gcd_terms(2 + 2*x) == Mul(2, 1 + x, evaluate=False)
arg = x*(2*x + 4*y)
garg = 2*x*(x + 2*y)
assert gcd_terms(arg) == garg
assert gcd_terms(sin(arg)) == sin(garg)
# issue 3040-like
alpha, alpha1, alpha2, alpha3 = symbols('alpha:4')
a = alpha**2 - alpha*x**2 + alpha + x**3 - x*(alpha + 1)
rep = (alpha, (1 + sqrt(5))/2 + alpha1*x + alpha2*x**2 + alpha3*x**3)
s = (a/(x - alpha)).subs(*rep).series(x, 0, 1)
assert simplify(collect(s, x)) == -sqrt(5)/2 - S(3)/2 + O(x)
# issue 2818
assert _gcd_terms([S.Zero, S.Zero]) == (0, 0, 1)
assert _gcd_terms([2*x + 4]) == (2, x + 2, 1)
def test_gcd_terms():
f = 2*(x + 1)*(x + 4)/(5*x**2 + 5) + (2*x + 2)*(x + 5)/(x**2 + 1)/5 + \
(2*x + 2)*(x + 6)/(5*x**2 + 5)
assert _gcd_terms(f) == ((Rational(6, 5)) * ((1 + x) / (1 + x**2)), 5 + x,
1)
assert _gcd_terms(Add.make_args(f)) == \
((Rational(6, 5))*((1 + x)/(1 + x**2)), 5 + x, 1)
newf = (Rational(6, 5)) * ((1 + x) * (5 + x) / (1 + x**2))
assert gcd_terms(f) == newf
args = Add.make_args(f)
# non-Basic sequences of terms treated as terms of Add
assert gcd_terms(list(args)) == newf
assert gcd_terms(tuple(args)) == newf
assert gcd_terms(set(args)) == newf
# but a Basic sequence is treated as a container
assert gcd_terms(Tuple(*args)) != newf
assert gcd_terms(Basic(Tuple(1, 3*y + 3*x*y), Tuple(1, 3))) == \
Basic((1, 3*y*(x + 1)), (1, 3))
# but we shouldn't change keys of a dictionary or some may be lost
assert gcd_terms(Dict((x*(1 + y), 2), (x + x*y, y + x*y))) == \
Dict({x*(y + 1): 2, x + x*y: y*(1 + x)})
assert gcd_terms((2 * x + 2)**3 +
(2 * x + 2)**2) == 4 * (x + 1)**2 * (2 * x + 3)
assert gcd_terms(0) == 0
assert gcd_terms(1) == 1
assert gcd_terms(x) == x
assert gcd_terms(2 + 2 * x) == Mul(2, 1 + x, evaluate=False)
arg = x * (2 * x + 4 * y)
garg = 2 * x * (x + 2 * y)
assert gcd_terms(arg) == garg
assert gcd_terms(sin(arg)) == sin(garg)
# issue 6139-like
alpha, alpha1, alpha2, alpha3 = symbols('alpha:4')
a = alpha**2 - alpha * x**2 + alpha + x**3 - x * (alpha + 1)
rep = (alpha,
(1 + sqrt(5)) / 2 + alpha1 * x + alpha2 * x**2 + alpha3 * x**3)
s = (a / (x - alpha)).subs(*rep).series(x, 0, 1)
assert simplify(collect(s, x)) == -sqrt(5) / 2 - Rational(3, 2) + O(x)
# issue 5917
assert _gcd_terms([S.Zero, S.Zero]) == (0, 0, 1)
assert _gcd_terms([2 * x + 4]) == (2, x + 2, 1)
eq = x / (x + 1 / x)
assert gcd_terms(eq, fraction=False) == eq
eq = x / 2 / y + 1 / x / y
assert gcd_terms(eq, fraction=True, clear=True) == \
(x**2 + 2)/(2*x*y)
assert gcd_terms(eq, fraction=True, clear=False) == \
(x**2/2 + 1)/(x*y)
assert gcd_terms(eq, fraction=False, clear=True) == \
(x + 2/x)/(2*y)
assert gcd_terms(eq, fraction=False, clear=False) == \
(x/2 + 1/x)/y
def test_gcd_terms():
f = 2*(x + 1)*(x + 4)/(5*x**2 + 5) + (2*x + 2)*(x + 5)/(x**2 + 1)/5 + \
(2*x + 2)*(x + 6)/(5*x**2 + 5)
assert _gcd_terms(f) == ((S(6)/5)*((1 + x)/(1 + x**2)), 5 + x, 1)
assert _gcd_terms(Add.make_args(f)) == \
((S(6)/5)*((1 + x)/(1 + x**2)), 5 + x, 1)
newf = (S(6)/5)*((1 + x)*(5 + x)/(1 + x**2))
assert gcd_terms(f) == newf
args = Add.make_args(f)
# non-Basic sequences of terms treated as terms of Add
assert gcd_terms(list(args)) == newf
assert gcd_terms(tuple(args)) == newf
assert gcd_terms(set(args)) == newf
# but a Basic sequence is treated as a container
assert gcd_terms(Tuple(*args)) != newf
assert gcd_terms(Basic(Tuple(1, 3*y + 3*x*y), Tuple(1, 3))) == \
Basic((1, 3*y*(x + 1)), (1, 3))
# but we shouldn't change keys of a dictionary or some may be lost
assert gcd_terms(Dict((x*(1 + y), 2), (x + x*y, y + x*y))) == \
Dict({x*(y + 1): 2, x + x*y: y*(1 + x)})
assert gcd_terms((2*x + 2)**3 + (2*x + 2)**2) == 4*(x + 1)**2*(2*x + 3)
assert gcd_terms(0) == 0
assert gcd_terms(1) == 1
assert gcd_terms(x) == x
assert gcd_terms(2 + 2*x) == Mul(2, 1 + x, evaluate=False)
arg = x*(2*x + 4*y)
garg = 2*x*(x + 2*y)
assert gcd_terms(arg) == garg
assert gcd_terms(sin(arg)) == sin(garg)
# issue 6139-like
alpha, alpha1, alpha2, alpha3 = symbols('alpha:4')
a = alpha**2 - alpha*x**2 + alpha + x**3 - x*(alpha + 1)
rep = (alpha, (1 + sqrt(5))/2 + alpha1*x + alpha2*x**2 + alpha3*x**3)
s = (a/(x - alpha)).subs(*rep).series(x, 0, 1)
assert simplify(collect(s, x)) == -sqrt(5)/2 - S(3)/2 + O(x)
# issue 5917
assert _gcd_terms([S.Zero, S.Zero]) == (0, 0, 1)
assert _gcd_terms([2*x + 4]) == (2, x + 2, 1)
eq = x/(x + 1/x)
assert gcd_terms(eq, fraction=False) == eq
eq = x/2/y + 1/x/y
assert gcd_terms(eq, fraction=True, clear=True) == \
(x**2 + 2)/(2*x*y)
assert gcd_terms(eq, fraction=True, clear=False) == \
(x**2/2 + 1)/(x*y)
assert gcd_terms(eq, fraction=False, clear=True) == \
(x + 2/x)/(2*y)
assert gcd_terms(eq, fraction=False, clear=False) == \
(x/2 + 1/x)/y
def test_make_args():
assert Add.make_args(x) == (x,)
assert Mul.make_args(x) == (x,)
assert Add.make_args(x*y*z) == (x*y*z,)
assert Mul.make_args(x*y*z) == (x*y*z).args
assert Add.make_args(x + y + z) == (x + y + z).args
assert Mul.make_args(x + y + z) == (x + y + z,)
assert Add.make_args((x + y)**z) == ((x + y)**z,)
assert Mul.make_args((x + y)**z) == ((x + y)**z,)
def test_gcd_terms():
f = 2*(x + 1)*(x + 4)/(5*x**2 + 5) + (2*x + 2)*(x + 5)/(x**2 + 1)/5 + (2*x + 2)*(x + 6)/(5*x**2 + 5)
assert _gcd_terms(f) == ((S(6)/5)*((1 + x)/(1 + x**2)), 5 + x, 1)
assert _gcd_terms(Add.make_args(f)) == ((S(6)/5)*((1 + x)/(1 + x**2)), 5 + x, 1)
assert gcd_terms(f) == (S(6)/5)*((1 + x)*(5 + x)/(1 + x**2))
assert gcd_terms(Add.make_args(f)) == (S(6)/5)*((1 + x)*(5 + x)/(1 + x**2))
assert gcd_terms(0) == 0
assert gcd_terms(1) == 1
assert gcd_terms(x) == x
def test_make_args():
assert Add.make_args(x) == (x, )
assert Mul.make_args(x) == (x, )
assert Add.make_args(x * y * z) == (x * y * z, )
assert Mul.make_args(x * y * z) == (x * y * z).args
assert Add.make_args(x + y + z) == (x + y + z).args
assert Mul.make_args(x + y + z) == (x + y + z, )
assert Add.make_args((x + y)**z) == ((x + y)**z, )
assert Mul.make_args((x + y)**z) == ((x + y)**z, )
def test_gcd_terms():
f = 2 * (x + 1) * (x + 4) / (5 * x**2 + 5) + (2 * x + 2) * (x + 5) / (
x**2 + 1) / 5 + (2 * x + 2) * (x + 6) / (5 * x**2 + 5)
assert _gcd_terms(f) == ((S(6) / 5) * ((1 + x) / (1 + x**2)), 5 + x, 1)
assert _gcd_terms(Add.make_args(f)) == ((S(6) / 5) *
((1 + x) / (1 + x**2)), 5 + x, 1)
assert gcd_terms(f) == (S(6) / 5) * ((1 + x) * (5 + x) / (1 + x**2))
assert gcd_terms(Add.make_args(f)) == (S(6) / 5) * ((1 + x) * (5 + x) /
(1 + x**2))
assert gcd_terms(0) == 0
assert gcd_terms(1) == 1
assert gcd_terms(x) == x
def test_gcd_terms():
f = 2*(x + 1)*(x + 4)/(5*x**2 + 5) + (2*x + 2)*(x + 5)/(x**2 + 1)/5 + (2*x + 2)*(x + 6)/(5*x**2 + 5)
assert _gcd_terms(f) == ((S(6)/5)*((1 + x)/(1 + x**2)), 5 + x, 1)
assert _gcd_terms(Add.make_args(f)) == ((S(6)/5)*((1 + x)/(1 + x**2)), 5 + x, 1)
assert gcd_terms(f) == (S(6)/5)*((1 + x)*(5 + x)/(1 + x**2))
assert gcd_terms(Add.make_args(f)) == (S(6)/5)*((1 + x)*(5 + x)/(1 + x**2))
assert gcd_terms((2*x + 2)**3 + (2*x + 2)**2) == 4*(x + 1)**2*(2*x + 3)
assert gcd_terms(0) == 0
assert gcd_terms(1) == 1
assert gcd_terms(x) == x
assert gcd_terms(2 + 2*x) == Mul(2, 1 + x, evaluate=False)
def _dict_from_basic_if_gens(ex, gens, **args):
"""Convert `ex` to a multinomial given a generators list. """
k, indices = len(gens), {}
for i, g in enumerate(gens):
indices[g] = i
result = {}
for term in Add.make_args(ex):
coeff, monom = [], [0] * k
for factor in Mul.make_args(term):
if factor.is_Number:
coeff.append(factor)
else:
try:
base, exp = _analyze_power(*factor.as_base_exp())
monom[indices[base]] = exp
except KeyError:
if not factor.has(*gens):
coeff.append(factor)
else:
raise PolynomialError(
"%s contains an element of the generators set" %
factor)
monom = tuple(monom)
if monom in result:
result[monom] += Mul(*coeff)
else:
result[monom] = Mul(*coeff)
return result
def cancel_terms(sym, x_term, coef):
if coef.is_Add:
for arg_c in coef.args:
sym = cancel_terms(sym, x_term, arg_c)
else:
terms = Add.make_args(sym)
return Add.fromiter(t for t in terms if t != x_term*coef)
def z_to_coeffs(poly):
"""
Get a dictionary ``{delay: coeff, ...}`` from a z-transform expressed as a
polynomial.
The returned dictionary will contain :py:class:`int` ``delay`` values and
SymPy expressions for the coefficients.
"""
# NB: Ideally you'd use SymPy's polynomial-related functions for this job
# but, alas, SymPy doesn't support Laurent polynomials (where powers may be
# negative). As a consequence, we do everything 'by hand'; using algebraic
# operations rather than inspecting the SymPy data structures for reasons
# of robustness.
# Simplify the polynomial into a summation of multiples of powers of z.
poly = collect(expand(poly), z)
out = {}
for arg in Add.make_args(poly):
arg_no_z = arg.subs(z, 1)
arg_z = arg / arg_no_z
delay = -int((log(arg_z) / log(z)).expand(force=True))
out[delay] = arg_no_z
# Add missing zeros terms (for completeness...)
for delay in range(min(out), max(out)):
out.setdefault(delay, 0)
return out
def _dict_from_basic_if_gens(ex, gens, **args):
"""Convert `ex` to a multinomial given a generators list. """
k, indices = len(gens), {}
for i, g in enumerate(gens):
indices[g] = i
result = {}
for term in Add.make_args(ex):
coeff, monom = [], [0]*k
for factor in Mul.make_args(term):
if factor.is_Number:
coeff.append(factor)
else:
try:
base, exp = _analyze_power(*factor.as_Pow())
monom[indices[base]] = exp
except KeyError:
if not factor.has(*gens):
coeff.append(factor)
else:
raise PolynomialError("%s contains an element of the generators set" % factor)
monom = tuple(monom)
if result.has_key(monom):
result[monom] += Mul(*coeff)
else:
result[monom] = Mul(*coeff)
return result
def _as_ordered_terms(self, expr, order=None):
"""A compatibility function for ordering terms in Add. """
order = order or self.order
if order == 'old':
return sorted(Add.make_args(expr), key=cmp_to_key(Basic._compare_pretty))
else:
return expr.as_ordered_terms(order=order)
def _as_ordered_terms(self, expr, order=None):
"""A compatibility function for ordering terms in Add. """
order = order or self.order
if order == 'old':
return sorted(Add.make_args(expr), key=cmp_to_key(Basic._compare_pretty))
else:
return expr.as_ordered_terms(order=order)
def test_gcd_terms():
f = 2 * (x + 1) * (x + 4) / (5 * x**2 + 5) + (2 * x + 2) * (x + 5) / (
x**2 + 1) / 5 + (2 * x + 2) * (x + 6) / (5 * x**2 + 5)
assert _gcd_terms(f) == ((S(6) / 5) * ((1 + x) / (1 + x**2)), 5 + x, 1)
assert _gcd_terms(Add.make_args(f)) == ((S(6) / 5) *
((1 + x) / (1 + x**2)), 5 + x, 1)
assert gcd_terms(f) == (S(6) / 5) * ((1 + x) * (5 + x) / (1 + x**2))
assert gcd_terms(Add.make_args(f)) == (S(6) / 5) * ((1 + x) * (5 + x) /
(1 + x**2))
assert gcd_terms((2 * x + 2)**3 +
(2 * x + 2)**2) == 4 * (x + 1)**2 * (2 * x + 3)
assert gcd_terms(0) == 0
assert gcd_terms(1) == 1
assert gcd_terms(x) == x
assert gcd_terms(2 + 2 * x) == Mul(2, 1 + x, evaluate=False)
def latex_multline(expr, breaks, env="multline*", prefix=""):
args = Add.make_args(expr)
breaks = zip([0] + breaks, breaks + [len(args)])
def fmt_line(i, j):
line = latex(Add(*args[i:j]))
if i != 0 and latex(Add(*args[i:j]))[0] != '-':
line = "+" + line
return prefix + line
return Latex("\\begin{{{0}}}\n{1}\n\\end{{{0}}}".format(
env, "\\\\\n".join([fmt_line(i, j) for i, j in breaks])))
def _expandsums(sums):
"""
Helper function for _eval_expand_mul.
sums must be a list of instances of Basic.
"""
L = len(sums)
if L == 1:
return sums[0].args
terms = []
left = MatSymbolicMul._expandsums(sums[:L // 2])
right = MatSymbolicMul._expandsums(sums[L // 2:])
terms = [MatSymbolicMul(a, b) for a in left for b in right]
added = MatSymbolicAdd(*terms)
return Add.make_args(added) # it may have collapsed down to one term
def collect_by_nc(expr, evaluate=True):
collected, disliked = defaultdict(list), S.Zero
for arg in Add.make_args(expr):
c, nc = arg.args_cnc()
if nc: collected[Mul(*nc)].append(Mul(*c))
else: disliked += Mul(*c)
collected = {k: Add(*v) for k, v in collected.items()}
if disliked is not S.Zero:
collected[S.One] = disliked
if evaluate:
return Add(*[key * val for key, val in collected.items()])
else:
return collected
def sectionSeparate(formula, lmax):
x = symbols('x', real=True)
pos = set([
x - LM(f).args[0] for f in Add.make_args(formula)
if len(f.atoms(StepFunc))
])
pos.update([0, lmax])
pos = list(sorted(pos))
st = 0
formularr = []
# print("Line Segment Function")
for en in pos[1:]:
# print(formula.expand(lim=st, func=True))
formularr.append((formula.expand(lim=st, func=True), (x, st, en)))
st = en
return formularr
def collect_by_order(expr, evaluate=True):
"""
return dict d such that expr == Add(*[d[n] for n in d])
where Expr d[n] contains only terms with operator order n
"""
args = Add.make_args(expr)
d = {}
for arg in args:
n = operator_order(arg)
if n in d: d[n] += arg
else: d[n] = arg
d = {n: factor(collect_by_nc(arg)) for n, arg in d.items()}
if evaluate:
return Add(*[arg for arg in d.values()], evaluate=False)
else:
return d
def _make_converter(K):
"""Construct the converter to convert back to Expr"""
# Precompute the effect of converting to sympy and expanding expressions
# like (sqrt(2) + sqrt(3))**2. Asking Expr to do the expansion on every
# conversion from K to Expr is slow. Here we compute the expansions for
# each power of the generator and collect together the resulting algebraic
# terms and the rational coefficients into a matrix.
from sympy import Add, S
gen = K.ext.as_expr()
todom = K.dom.from_sympy
# We'll let Expr compute the expansions. We won't make any presumptions
# about what this results in except that it is QQ-linear in some terms
# that we will call algebraics. The final result will be expressed in
# terms of those.
powers = [S.One, gen]
for n in range(2, K.mod.degree()):
powers.append((gen * powers[-1]).expand())
# Collect the rational coefficients and algebraic Expr that can
# map the ANP coefficients into an expanded sympy expression
terms = [
dict(t.as_coeff_Mul()[::-1] for t in Add.make_args(p)) for p in powers
]
algebraics = set().union(*terms)
matrix = [[todom(t.get(a, S.Zero)) for t in terms] for a in algebraics]
# Create a function to do the conversion efficiently:
def converter(a):
"""Convert a to Expr using converter"""
from sympy import Add, Mul
ai = a.rep[::-1]
tosympy = K.dom.to_sympy
coeffs_dom = [
sum(mij * aj for mij, aj in zip(mi, ai)) for mi in matrix
]
coeffs_sympy = [tosympy(c) for c in coeffs_dom]
res = Add(*(Mul(c, a) for c, a in zip(coeffs_sympy, algebraics)))
return res
return converter
def analyze(self, expr):
"""Rewrite an expression as sorted list of terms. """
gens, terms = set([]), []
for term in Add.make_args(expr):
coeff, cpart, ncpart = [], {}, []
for factor in Mul.make_args(term):
if not factor.is_commutative:
ncpart.append(factor)
else:
if factor.is_Number:
coeff.append(factor)
else:
base, exp = _analyze_power(*factor.as_base_exp())
cpart[base] = exp
gens.add(base)
terms.append((coeff, cpart, ncpart, term))
gens = sorted(gens, Basic._compare_pretty)
k, indices = len(gens), {}
for i, g in enumerate(gens):
indices[g] = i
result = []
for coeff, cpart, ncpart, term in terms:
monom = [0] * k
for base, exp in cpart.iteritems():
monom[indices[base]] = exp
result.append((coeff, monom, ncpart, term))
if self.order is None:
return sorted(result, Basic._compare_pretty)
else:
return sorted(result, self._compare_terms)
def analyze(self, expr):
"""Rewrite an expression as sorted list of terms. """
gens, terms = set([]), []
for term in Add.make_args(expr):
coeff, cpart, ncpart = [], {}, []
for factor in Mul.make_args(term):
if not factor.is_commutative:
ncpart.append(factor)
else:
if factor.is_Number:
coeff.append(factor)
else:
base, exp = _analyze_power(*factor.as_base_exp())
cpart[base] = exp
gens.add(base)
terms.append((coeff, cpart, ncpart, term))
gens = sorted(gens, Basic._compare_pretty)
k, indices = len(gens), {}
for i, g in enumerate(gens):
indices[g] = i
result = []
for coeff, cpart, ncpart, term in terms:
monom = [0]*k
for base, exp in cpart.iteritems():
monom[indices[base]] = exp
result.append((coeff, monom, ncpart, term))
if self.order is None:
return sorted(result, Basic._compare_pretty)
else:
return sorted(result, self._compare_terms)
def impluseFind(expr):
x = symbols('x', real=True)
imparr = []
for ex in Add.make_args(expr):
mul = 1
x_impulse = x_moment = None
for f in Mul.make_args(ex):
if isinstance(f, StepFunc):
if f.args[1] == -1:
x_impulse = x - f.args[0]
if f.args[1] == -2:
x_moment = x - f.args[0]
else:
mul *= f
if x_impulse != None:
imparr.append((x_impulse, mul, -1))
elif x_moment != None:
imparr.append((x_moment, mul, -2))
return imparr
def weightMul(expr, wei, lmax):
x = symbols("x", real=True)
wei = weightFill(wei, lmax)
f = 0
for term in Add.make_args(expr):
xfrm = 0
expterm = term
for m in Mul.make_args(term):
if isinstance(m, StepFunc):
xfrm = x - m.args[0]
expterm = term.expand(lim=lmax, func=True)
func = m
for w in wei:
# outside range
if w[2] <= xfrm:
continue
# partical inside range
elif w[1] <= xfrm <= w[2]:
f += buildStep(expterm * w[0], lmax, 0, xfrm, w[2])
# inside range
else:
f += buildStep(expterm * w[0], lmax, 0, w[1], w[2])
return f
def latex_align(data,
env="align*",
delim=None,
breaks=None): # or set col_delim="&" for auto align
if isinstance(data, list):
delim = " " if delim is None else delim
body = " \\\\\n".join(
[delim.join([latex(col) for col in row]) for row in data])
if isinstance(data, Basic):
args = Add.make_args(data)
delim = "& " if delim is None else delim
breaks = range(4, len(args) - 3, 4) if breaks is None else breaks
breaks = zip([0] + list(breaks), list(breaks) + [len(args)])
def fmt_line(i, j):
line = latex(Add(*args[i:j]))
if i != 0 and latex(Add(*args[i:j]))[0] != '-':
line = "+" + line
return delim + line
body = "\\\\\n".join([fmt_line(i, j) for i, j in breaks])
return Latex("\\begin{{{0}}}\n{1}\n\\end{{{0}}}".format(env, body))
def _dict_from_basic_no_gens(ex, **args):
"""Figure out generators and convert `ex` to a multinomial. """
domain = args.get('domain')
if domain is not None:
def _is_coeff(factor):
return factor in domain
else:
extension = args.get('extension')
if extension is True:
def _is_coeff(factor):
return ask(factor, 'algebraic')
else:
greedy = args.get('greedy', True)
if greedy is True:
def _is_coeff(factor):
return False
else:
def _is_coeff(factor):
return factor.is_number
gens, terms = set([]), []
for term in Add.make_args(ex):
coeff, elements = [], {}
for factor in Mul.make_args(term):
if factor.is_Number or _is_coeff(factor):
coeff.append(factor)
else:
base, exp = _analyze_power(*factor.as_base_exp())
elements[base] = exp
gens.add(base)
terms.append((coeff, elements))
if not gens:
raise GeneratorsNeeded("specify generators to give %s a meaning" % ex)
gens = _sort_gens(gens, **args)
k, indices = len(gens), {}
for i, g in enumerate(gens):
indices[g] = i
result = {}
for coeff, term in terms:
monom = [0] * k
for base, exp in term.iteritems():
monom[indices[base]] = exp
monom = tuple(monom)
if monom in result:
result[monom] += Mul(*coeff)
else:
result[monom] = Mul(*coeff)
return result, tuple(gens)
def get_max_coef_list(sym, x_term):
return [get_max_coef_mul(s, x_term) for s in Add.make_args(sym)]
def get_max_coef(sym, x_term):
return Add.fromiter(
get_max_coef_mul(s, x_term) for s in Add.make_args(sym)
)
def test_identity_removal():
assert Add.make_args(x + 0) == (x,)
assert Mul.make_args(x*1) == (x,)
def _dict_from_basic_no_gens(ex, **args):
"""Figure out generators and convert `ex` to a multinomial. """
domain = args.get('domain')
if domain is not None:
def _is_coeff(factor):
return factor in domain
else:
extension = args.get('extension')
if extension is True:
def _is_coeff(factor):
return ask(factor, 'algebraic')
else:
greedy = args.get('greedy', True)
if greedy is True:
def _is_coeff(factor):
return False
else:
def _is_coeff(factor):
return factor.is_number
gens, terms = set([]), []
for term in Add.make_args(ex):
coeff, elements = [], {}
for factor in Mul.make_args(term):
if factor.is_Number or _is_coeff(factor):
coeff.append(factor)
else:
base, exp = _analyze_power(*factor.as_Pow())
elements[base] = exp
gens.add(base)
terms.append((coeff, elements))
if not gens:
raise GeneratorsNeeded("specify generators to give %s a meaning" % ex)
gens = _sort_gens(gens, **args)
k, indices = len(gens), {}
for i, g in enumerate(gens):
indices[g] = i
result = {}
for coeff, term in terms:
monom = [0]*k
for base, exp in term.iteritems():
monom[indices[base]] = exp
monom = tuple(monom)
if result.has_key(monom):
result[monom] += Mul(*coeff)
else:
result[monom] = Mul(*coeff)
return result, tuple(gens)
def collect_const(expr, *vars, **kwargs):
""" This is the very same code of sympy.simplify.radsimp.py collect_const,
with modification: the original method used Mul._from_args
and Add._from_args, which do not call a post-processor, hence I obtained the
wrong result. Here, I use VecAdd, VecMul...
"""
if not expr.is_Add:
return expr
recurse = False
Numbers = kwargs.get('Numbers', True)
if not vars:
recurse = True
vars = set()
for a in expr.args:
for m in Mul.make_args(a):
if m.is_number:
vars.add(m)
else:
vars = sympify(vars)
if not Numbers:
vars = [v for v in vars if not v.is_Number]
vars = list(ordered(vars))
for v in vars:
terms = defaultdict(list)
Fv = Factors(v)
for m in Add.make_args(expr):
f = Factors(m)
q, r = f.div(Fv)
if r.is_one:
# only accept this as a true factor if
# it didn't change an exponent from an Integer
# to a non-Integer, e.g. 2/sqrt(2) -> sqrt(2)
# -- we aren't looking for this sort of change
fwas = f.factors.copy()
fnow = q.factors
if not any(k in fwas and fwas[k].is_Integer
and not fnow[k].is_Integer for k in fnow):
terms[v].append(q.as_expr())
continue
terms[S.One].append(m)
args = []
hit = False
uneval = False
for k in ordered(terms):
v = terms[k]
if k is S.One:
args.extend(v)
continue
if len(v) > 1:
v = Add(*v)
hit = True
if recurse and v != expr:
vars.append(v)
else:
v = v[0]
# be careful not to let uneval become True unless
# it must be because it's going to be more expensive
# to rebuild the expression as an unevaluated one
if Numbers and k.is_Number and v.is_Add:
# args.append(_keep_coeff(k, v, sign=True))
args.append(VecMul(*[k, v], evaluate=False))
uneval = True
else:
args.append(k * v)
if hit:
if uneval:
# expr = Add(*args)
expr = VecAdd(*args, evaluate=False)
else:
# expr = Add(*args)
expr = VecAdd(*args)
if not expr.is_Add:
break
return expr
def test_identity_removal():
assert Add.make_args(x + 0) == (x, )
assert Mul.make_args(x * 1) == (x, )