Bugs and strange behaviours of Maxima with ratmx and sparse set to true



-----maxima-bounces at math.utexas.edu wrote: -----

>> I think it could be better to use something like
>> fast_linsolve or linsolve_by_lu rather than inversion.

>Yes, maybe... but I need to keep all the things in a vector form, so
>inversion is (I think) the best way to do it.

Maybe you have already solved your problem; for what it is worth, I'd try
something like:

(%i19) algebraic : true$
(%i20) ratmx : true$

(%i21) KT : triangularize(K)$
Evaluation took 0.2900 seconds (0.2900 elapsed)

(%i22) last(KT);
(%o22)
[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,(5072270477230080*bk^17*l^67*A^7*E^21
+2028908190892032*bk^18*l^68*A^6*E^20)*I^14]

(%i23) factor(last(%));
(%o23) 1014454095446016*bk^17*l^67*A^6*E^20*(5*A*E+2*bk*l)*I^14


Barton