Dear Sage Developers:
There seems to be a similar issue in Sage Version 4.8:
sage: a=log(6)/(1+log(2))
sage: (6*exp(-a)-2^a).full_simplify()
-(2^(log(3)/(log(2) + 1) + 1/(log(2) + 1))*3^(1/(log(2) +
1))*e^(log(2)^2/(log(2) + 1)) - 6)/(2^(1/(log(2) + 1))*3^(1/(log(2) + 1)))
sage:
In gmane.comp.mathematics.sage.support, you wrote:
Dear Sage Developers:
There seems to be a similar issue in Sage Version 4.8:
sage: a=log(6)/(1+log(2))
sage: (6*exp(-a)-2^a).full_simplify()
-(2^(log(3)/(log(2) + 1) + 1/(log(2) + 1))*3^(1/(log(2) +
1))*e^(log(2)^2/(log(2) + 1))
On 01/15/12 13:18, JamesHDavenport wrote:
Thanks. Given that, here's the sagenb (4.7.2) version, showing the bug
(wrong when t is negative real):
sage: t=var('t')
sage: f=(1/2)*log(2*t)+(1/2)*log(1/t)
sage: f.full_simplify()
1/2*log(2)
I created a ticket for this here:
I was using sagenb,org, so the output isn't actually a SAGE session,
but pasting from sagenb.org. It says it is 4.7.2.
Glad it's fixed. I guess I ought to download a 4.8 if I'm really going
to comment in more detail, given the apparent changes.
On Jan 14, 1:47 am, Michael Orlitzky
Unfortunately, full_simplify has its own problems, notably with branch
cuts.
sage: f = (1/2)*log(2*t) + (1/2)*log(-t)
sage: f.full_simplify()
1/2*log(2)
Unfortunately, when t=-1, we have the sum of the logarithms of two
negative numbers, and therefore the imaginary part is 2i pi, not 0
On Jan 12,
On 01/13/2012 07:38 PM, JamesHDavenport wrote:
Unfortunately, full_simplify has its own problems, notably with branch
cuts.
sage: f = (1/2)*log(2*t) + (1/2)*log(-t)
sage: f.full_simplify()
1/2*log(2)
In my session, I had the difference of two logarithms. In yours above,
you've got the sum. Is
