Re: solve question/simplify question

*To*: mathgroup at smc.vnet.net*Subject*: [mg55572] Re: solve question/simplify question*From*: "Jens-Peer Kuska" <kuska at informatik.uni-leipzig.de>*Date*: Wed, 30 Mar 2005 03:21:05 -0500 (EST)*Organization*: Uni Leipzig*References*: <d2341s$lgg$1@smc.vnet.net>*Sender*: owner-wri-mathgroup at wolfram.com

Hi, solving a linear system of equations of dimension n is a n^2 process and for nonlinear systems it depends on the system. So a larger system will need more time. To impove the memory usage you may substitute common terms in your expression. But this depend on the detailed form of the expression . Regards Jens "Paul Schneider" <paulibaer at uboot.com> schrieb im Newsbeitrag news:d2341s$lgg$1 at smc.vnet.net... > Hi, > > I have a list called equns of linear equations > which are independent of > each other. The according variables are in a > list called params. I solve > the equations into a list called sol using > > sol = Solve[equns, params]; > > Can I expect the solution procedure to be faster > or in favor of memory > usage if I iterate through the elements of the > lists and solve for each > equation separately? Same question goes for > Simplify. > > I don't want to try and find out myself because > I have noticed big > differences in running times with Mathematica > and I am not sure how to > test for improved speed. The equations are > enormous and I don't know in > advance how they look like, so I can't use the > linear algebra routines. > > My second question goes to memory management. > Even though I have lots of > memory it gets maxed out pretty quickly when I > use Simplify, or > FullSimplify on the solutions of those huge > equations. So I tried to get > rid of expressinos that are not needed anymore > by > > Clear[var] > or > var = . > > as is proposed in the help files. I also tried > Share[ ]. But it doesn't > seem to do anything. How can I improve this > situation. > > Thank you, > > Paul >