Hi,
It seems computations in QQbar is sometimes much slower in Sage
4.3 than in the previous version. Here is an example (I am sorry
if it is too convoluted):
v1 = sqrt(QQbar(3))
v2 = QQbar(999/1000*I)
v3 = (1 + v1)/2 + v2*(-3 - v1)/2
v4 = (3 - v1)/2 + v2*(1 - v1)/2
v5 = v3*(1/2) + v4*QQbar(500/999*I)
v6 = v3*(1/2) + v4*QQbar(-500/999*I)
v7 = -(v5/v6).conjugate() - QQbar(abs(v5))/v5/v6.conjugate()*QQbar(I)
v8 = -(v5/v6).conjugate() + QQbar(abs(v5))/v5/v6.conjugate()*QQbar(I)
v9 = abs(v8)
v10 = abs(v7)
v11 = (v7 - v8 + QQbar(v9*v9)*v7 - QQbar(v10*v10)*v8)/\
(v8.conjugate()*v7 - v7.conjugate()*v8)
v12 = (v11*QQbar(I) - QQbar(-I)*v11.conjugate())/2/QQbar(I)
v13 = abs(v12)
v14 = QQbar(1 - sqrt(1 - 1/(v13*v13)))*v12
time real(v14)
In Sage 4.3 I get the output:
Exception TypeError: TypeError('Unable to convert number to real
interval.',) in 'sage.symbolic.pynac.py_is_real' ignored
CPU times: user 67.94 s, sys: 0.30 s, total: 68.23 s
Wall time: 68.68 s
-0.5773508481209188?
In Sage 4.2.1 on the same computer I get the output:
CPU times: user 0.00 s, sys: 0.00 s, total: 0.00 s
Wall time: 0.00 s
-0.5773508481209188?
Should this be considered a bug?
/Håkan
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