def LM(self,poly):
from sympy import S,Poly
if poly==0:return poly
poly = Poly(poly,self.variables)
polyDict = poly.as_dict()
exponents = polyDict.keys()
largest = exponents[0]
for i in xrange(len(polyDict)):
if self.compare(exponents[i],largest): largest = exponents[i]
return Poly({largest:S(1)},self.variables)
def test_poly_internals():
p = Poly(x**2*y*z + x*y*z**3 + x*y + y*z, x, y, z)
assert p.as_dict() == \
{(1, 1, 3): 1, (1, 1, 0): 1, (2, 1, 1): 1, (0, 1, 1): 1}
assert Poly._permute(p, x) == \
{(2,): y*z, (0,): y*z, (1,): y + y*z**3}
assert Poly._permute(p, y) == \
{(1,): x + z + x*z**3 + z*x**2}
assert Poly._permute(p, z) == \
{(0,): x*y, (3,): x*y, (1,): y + y*x**2}
assert Poly._permute(p, x, y) == \
{(0, 1): z, (1, 1): 1 + z**3, (2, 1): z}
assert Poly._permute(p, y, x) == \
{(1, 2): z, (1, 0): z, (1, 1): 1 + z**3}
assert Poly._permute(p, x, z) == \
{(0, 1): y, (1, 0): y, (1, 3): y, (2, 1): y}
assert Poly._permute(p, z, x) == \
{(1, 2): y, (0, 1): y, (1, 0): y, (3, 1): y}
assert Poly._permute(p, y, z) == \
{(1, 0): x, (1, 3): x, (1, 1): 1 + x**2}
assert Poly._permute(p, z, y) == \
{(0, 1): x, (3, 1): x, (1, 1): 1 + x**2}
q = Poly(x**2*y*z + 2*x*y*z**3 + 3*x*y + 4*y*z, x, y, z)
assert q.as_dict() == \
{(1, 1, 3): 2, (1, 1, 0): 3, (2, 1, 1): 1, (0, 1, 1): 4}
assert Poly._permute(q, z, y, x) == \
{(0, 1, 1): 3, (1, 1, 0): 4, (3, 1, 1): 2, (1, 1, 2): 1}
def test_poly_internals():
p = Poly(x**2*y*z + x*y*z**3 + x*y + y*z, x, y, z)
assert p.as_dict() == \
{(1, 1, 3): 1, (1, 1, 0): 1, (2, 1, 1): 1, (0, 1, 1): 1}
assert Poly._permute(p, x) == \
{(2,): y*z, (0,): y*z, (1,): y + y*z**3}
assert Poly._permute(p, y) == \
{(1,): x + z + x*z**3 + z*x**2}
assert Poly._permute(p, z) == \
{(0,): x*y, (3,): x*y, (1,): y + y*x**2}
assert Poly._permute(p, x, y) == \
{(0, 1): z, (1, 1): 1 + z**3, (2, 1): z}
assert Poly._permute(p, y, x) == \
{(1, 2): z, (1, 0): z, (1, 1): 1 + z**3}
assert Poly._permute(p, x, z) == \
{(0, 1): y, (1, 0): y, (1, 3): y, (2, 1): y}
assert Poly._permute(p, z, x) == \
{(1, 2): y, (0, 1): y, (1, 0): y, (3, 1): y}
assert Poly._permute(p, y, z) == \
{(1, 0): x, (1, 3): x, (1, 1): 1 + x**2}
assert Poly._permute(p, z, y) == \
{(0, 1): x, (3, 1): x, (1, 1): 1 + x**2}
q = Poly(x**2*y*z + 2*x*y*z**3 + 3*x*y + 4*y*z, x, y, z)
assert q.as_dict() == \
{(1, 1, 3): 2, (1, 1, 0): 3, (2, 1, 1): 1, (0, 1, 1): 4}
assert Poly._permute(q, z, y, x) == \
{(0, 1, 1): 3, (1, 1, 0): 4, (3, 1, 1): 2, (1, 1, 2): 1}
def new_poly(V_s, fields, n_coeffs):
"""Make a new polynomial function that has the same powers as V_s function
but with coefficients C1, C2..."""
from sympy import Poly
from sympy import diff, Symbol, var, simplify, sympify, S
from sympy.core.sympify import SympifyError
P = Poly(V_s, *fields)
d = P.as_dict()
e = {}
for key in d.iterkeys():
#print d[key], str(d[key])
for i in xrange(1, n_coeffs + 1):
if 'C' + str(i) in str(d[key]):
e[key] = sympify('C' + str(i))
P2 = Poly(e, *fields)
return str(P2.as_basic())
def new_poly(V_s, fields, n_coeffs):
"""Make a new polynomial function that has the same powers as V_s function
but with coefficients C1, C2..."""
from sympy import Poly
from sympy import diff, Symbol, var, simplify, sympify, S
from sympy.core.sympify import SympifyError
P = Poly(V_s,*fields)
d = P.as_dict()
e = {}
for key in d.iterkeys():
#print d[key], str(d[key])
for i in xrange(1, n_coeffs+1):
if 'C' + str(i) in str(d[key]):
e[key] = sympify('C'+str(i))
P2 = Poly(e,*fields)
return str(P2.as_basic())
def _expansion_search(expr, rep_list, lib=None):
"""
Search for and substitute terms that match a series expansion of
fundamental math functions.
e: expression
rep_list: list containing dummy variables
"""
if debug:
print("_expansion_search: ", expr)
try:
if isinstance(expr, Mul):
exprs = [expr]
elif isinstance(expr, Add):
exprs = expr.args
else:
return expr
if lib is not None:
fncs, series = lib
else:
fncs, series = _fncs, _series
newargs = []
for expr in exprs:
# Try to simplify the expression
if isinstance(expr, Mul):
# Split the expression into a LIST of commutative and a LIST of non-commutative factor (i.e. operators).
c, nc = expr.args_cnc()
if nc and c:
# Construct an expression of commutative elements ONLY.
expr = Mul(*c).expand()
#out = find_expansion(expr, *rep_list)
eq = Poly(expr, *rep_list)
bdict = eq.as_dict()
if any([
n > 1 for n in
[sum([i != 0 for i in k]) for k in bdict.keys()]
]):
raise ValueError(
"Expressions cross-products of symbols are not supported (yet?).."
)
# Construct the list of 'vectors'
vecl = []
fncl = []
for x in rep_list:
for n in range(3): #range(eq.degree()-1):
X = pow(x, n)
vecl.extend([((X * p.subs(_s, x)).expand() +
O(pow(x,
eq.degree() + 1))).removeO()
for p in series])
fncl.extend([X * f(x) for f in fncs])
vecl.extend(
[pow(x, n) for n in range(max(eq.degree(), 3))])
fncl.extend(
[pow(x, n) for n in range(max(eq.degree(), 3))])
# Create vector coefficients
q = symbols(f'q:{len(vecl)}')
# Take inner product of 'vector' list and vector coefficients
A = Add(*[x * y
for x, y in zip(q, vecl)]).as_poly(*rep_list)
terms = []
for k, eq in A.as_dict().items():
terms.append(eq - bdict.get(k, 0))
H = linsolve(terms, *q)
h = H.subs({k: 0 for k in q})
out = Add(*[c * fnc for fnc, c in zip(fncl, list(h)[0])])
newargs.append(out * Mul(*nc))
else:
newargs.append(expr)
else:
newargs.append(expr)
return Add(*newargs)
except Exception as e:
print("Failed to identify series expansions: " + str(e))
return e
