On Mon, 5 Jun 2006, Robert Dodier wrote:
> You will probably have to help Maxima find a solution, by (say) applying
> some kind of divide and conquer. I don't know if that's possible in the
> problem that you are working on.
Thanks for the advice. By "divide and conquer," do you mean something
like:
x^2+y = x/(1-y^2) ;
solve(%, x) ;
x : ev(x, %) ;
(3*x+y^3)/(1+x) = x*y-x^3 ;
solve(%, y) ;
y : ev(y, %) ;
as opposed to
x^2+y = x/(1-y^2) ;
(3*x+y^3)/(1+x) = x*y-x^3 ;
solve([%th(1), %th(2)], [x, y]) ;
?
The former is what I'm doing at the moment, although I've also tried
the latter in the past. Maxima has managed to come up with
expressions for nine of the eleven variables I'm trying to solve for,
and is currently working on the tenth. Still no sign of out-of-memory
errors with the recompiled GCL. I'm not inclined to give up on the
current run yet: although Maxima has been running the calculation for
four days, it's only applied about half an hour of CPU time to it,
presumably because it's having to spend most of the time waiting for
swap, due to the huge memory demand.
--
Regards,
Dan