Re: Question from a biologist

*To*: mathgroup at smc.vnet.net*Subject*: [mg70475] Re: Question from a biologist*From*: "ben" <benjamin.friedrich at gmail.com>*Date*: Tue, 17 Oct 2006 02:59:03 -0400 (EDT)*References*: <egv9ah$r80$1@smc.vnet.net>

Dear tnad, could you describe your problem in more detail, e.g. give an example? One way to set something to zero in a sea of equations is equations/.{x[t]->x0,D[x[t],t]->0}. Maybe this is useful. Bye Ben tnad schrieb: > I'm trying to simulate some chemical reactions in mathematica using ODEs. I want to keep some of the variables (the parameters in the differential equations) constant during the simulation. Right now, I have to look for the first derivative of every variable in a sea of differential equations and set it to zero. Is there a more "elegant" way to do this in mathematica?