Comment #16 on issue 694 by asmeurer: Add tests from "Review of CAS
mathematical capabilities", by Michael Wester
http://code.google.com/p/sympy/issues/detail?id=694
I'm having trouble with test M3: solve(x**4+x**3+x**2+x+1,x)
Plugging this expression in to SymPy generates a humongous expression.
With my terminal fullscreen (238x58), the
solution list fills my whole screen with pretty printing turned off, and
several screens with it turned on (obviously, I refrain
from pasting it here). Running
l = []
s = solve(x**4+x**3+x**2+x+1,x)
for i in s:
l.append(simplify(i))
reduces the size of the output to about half of my screen, but it is still
huge. I ran the test command in Maple, and got
f:=solve(x**4+x**3+x**2+x+1,x);
f:=-1/4+(1/4)*sqrt(5)+(1/4*I)*sqrt(2)*sqrt(5+sqrt(5)),
-1/4-(1/4)*sqrt(5)+(1/4*I)*sqrt(2)*sqrt(5-sqrt(5)), -1/4-
(1/4)*sqrt(5)-(1/4*I)*sqrt(2)*sqrt(5-sqrt(5)),
-1/4+(1/4)*sqrt(5)-(1/4*I)*sqrt(2)*sqrt(5+sqrt(5))
I had no luck getting even Maple to simplify the SymPy expression down to
this, though that could just be because I am
relatively new to Maple. I was able to determine that they are the same
solutions by numerically evaluating them both.
Test M4 is verify a solution of M3, but
for i in s:
print simplify((x**4+x**3+x**2+x+1).subs({x:i}))
raises a maximum recursion error. Removing the simplify just makes each
print fill the whole screen (they should all be 0).
Any idea how to make this return a more simplified expression? Should I
report this as a bug? The solution SymPy gives is
technically correct (I think), but I hardly feel that this should write an
assert line in the test_wester.py that is several hundred
characters long when it could be much simpler.
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