Status: New
Owner: ----
Labels: Type-Defect Priority-Medium

New issue 1880 by [email protected]: Matrix(...).det() takes forever
http://code.google.com/p/sympy/issues/detail?id=1880

I just checked out current master branch and test this:

E = Symbol('E')
J = Symbol('J')
F = Symbol('F')
lmbda = Symbol('lambda')
L = Symbol('L')

KEG = Matrix([[(3000*E*J - 4*F*lmbda*L**2)/(75*L), (-1500*E*J +
F*lmbda*L**2)/(10*L**2), (1500*E*J + F*lmbda*L**2)/(150*L), 0, 0, 0, 0,
0], [(-1500*E*J + F*lmbda*L**2)/(10*L**2), (3000*E*J - 12*F*lmbda*L**2)/
L**3, 0, (-1500*E*J + 6*F*lmbda*L**2)/L**3, -(1500*E*J + F*lmbda*L**2)/
(10*L**2), 0, 0, 0], [(1500*E*J + F*lmbda*L**2)/(150*L), 0, (3000*E*J -
4*F*lmbda*L**2)/(75*L), (-1500*E*J + F*lmbda*L**2)/(10*L**2), (1500*E*J +
F*lmbda*L**2)/(150*L), 0, 0, 0], [0, (-1500*E*J + 6*F*lmbda*L**2)/L**3,
(-1500*E*J + F*lmbda*L**2)/(10*L**2), (3000*E*J - 12*F*lmbda*L**2)/L**3,
0, (-1500*E*J + 6*F*lmbda*L**2)/L**3, 0, 0], [0, -(1500*E*J +
F*lmbda*L**2)/(10*L**2), (1500*E*J + F*lmbda*L**2)/(150*L), 0, (3000*E*J -
4*F*lmbda*L**2)/(75*L), (-1500*E*J + F*lmbda*L**2)/(10*L**2), 0, 0], [0,
0, 0, (-1500*E*J + 6*F*lmbda*L**2)/L**3, (-1500*E*J + F*lmbda*L**2)/
(10*L**2), (3000*E*J - 12*F*lmbda*L**2)/L**3, (-1500*E*J + 6*F*lmbda*L**2)/
L**3, -(1500*E*J + F*lmbda*L**2)/(10*L**2)], [0, 0, 0, 0, 0, (-1500*E*J +
6*F*lmbda*L**2)/L**3, (1500*E*J - 6*F*lmbda*L**2)/L**3, (-1500*E*J +
F*lmbda*L**2)/(10*L**2)], [0, 0, 0, 0, 0, -(1500*E*J + F*lmbda*L**2)/
(10*L**2), (-1500*E*J + F*lmbda*L**2)/(10*L**2), (1500*E*J -
2*F*lmbda*L**2)/(75*L)]])

print KEG.det()
-21601054687500000000*E**8*J**8/L**16 +
508232812500000000*F*lmbda*E**7*J**7/L**14 -
4269543750000000*E**6*F**2*J**6*lmbda**2/L**12 +
16194716250000*E**5*F**3*J**5*lmbda**3/L**10 -
27633173750*E**4*F**4*J**4*lmbda**4/L**8 +
14840215*E**3*F**5*J**3*lmbda**5/L**6 + 54794*E**2*F**6*J**2*lmbda**6/
(5*L**4) - 1153*E*J*F**7*lmbda**7/(80*L**2) + 633*F**8*lmbda**8/160000

works pretty fast like this in current release, but takes forever in
current master branch (commit 6fd84163f1258ee6eb2c24d3d879ba4debd53320)


--
You received this message because you are listed in the owner
or CC fields of this issue, or because you starred this issue.
You may adjust your issue notification preferences at:
http://code.google.com/hosting/settings

--
You received this message because you are subscribed to the Google Groups 
"sympy-issues" group.
To post to this group, send email to [email protected].
To unsubscribe from this group, send email to 
[email protected].
For more options, visit this group at 
http://groups.google.com/group/sympy-issues?hl=en.

Reply via email to