Re: Precision when solving a system of differential equations
- To: mathgroup at smc.vnet.net
- Subject: [mg81841] Re: Precision when solving a system of differential equations
- From: Jens-Peer Kuska <kuska at informatik.uni-leipzig.de>
- Date: Thu, 4 Oct 2007 04:34:35 -0400 (EDT)
- Organization: Uni Leipzig
- References: <fdve27$t1e$1@smc.vnet.net>
- Reply-to: kuska at informatik.uni-leipzig.de
Hi, you can't because NDSolve[] determine the step size from the precision you set. You can reduce the precision that NDSolve[] use but that is usual not a good idea. In a stiff equation one has typical to made some very small steps but when the system relaxes the step size can grow. So it is not a good idea to set a lower limit for the step size. You should trust the step size control. Regards Jens Marc VIAL wrote: > Hi, > > I have a system with three differential equations with time as my variable. > I would like to control the increment time step as some of my function are > very stiff. Ideally I would like to use between 10 and 20 millions steps. > How can I do that? > (version used Mathematica 6.0.1) > > Thanks for help > Marc > _________________________________________________________________ >