Comment #12 on issue 3223 by [email protected]: degree((x+1)**10000)
takes too long
http://code.google.com/p/sympy/issues/detail?id=3223
After going through the source code, I devised that changing degree
functions to the following in polytools.py
Line no :1662
def degree(f, gen=0):
"""
Returns degree of ``f`` in ``x_j``.
Examples
========
>>> from sympy import Poly
>>> from sympy.abc import x, y
>>> Poly(x**2 + y*x + 1, x, y).degree()
2
>>> Poly(x**2 + y*x + y, x, y).degree(y)
1
"""
j = f._gen_to_level(gen)
if f.args[0].is_polynomial:
eq=f.args[0]
if not gen:
gen=f.gen
try:
return -eq.subs(gen,1/gen).leadterm(gen)[1]
except:
if hasattr(f.rep,'degree'):
return f.rep.degree(j)
else:
raise OperationNotSupported(f, 'degree')
if hasattr(f.rep,'degree'):
return f.rep.degree(j)
else:
raise OperationNotSupported(f, 'degree')
Line no: 39**
def degree(f, *gens, **args):
"""
Return the degree of ``f`` in the given variable.
Examples
========
>>> from sympy import degree
>>> from sympy.abc import x, y
>>> degree(x**2 + y*x + 1, gen=x)
2
>>> degree(x**2 + y*x + 1, gen=y)
1
"""
options.allowed_flags(args, ['gen', 'polys'])
try:
if f.is_polynomial:
eq=f
if not gens:
gen=f.gen
else:
gen=gens[0]
try:
return -eq.subs(gen,1/gen).leadterm(gen)[1]
except:
F, opt = poly_from_expr(f, *gens, **args)
return Integer(F.degree(opt.gen))
except PolificationFailed, exc:
raise ComputationFailed('degree', 1, exc)
except:
F, opt = poly_from_expr(f, *gens, **args)
return Integer(F.degree(opt.gen))
could act as a quick solution to the time required in materializing degrees
of the functions as described in this issue. It would be highly encouraging
if someone could guide me if i am thinking in the right direction or not
I have also attached my polytools.py with the above changes.
Attachments:
polytools.py 147 KB
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