optimizing

*To*: mathgroup at smc.vnet.net*Subject*: [mg74856] optimizing*From*: kaiwan <miroslav_marecic at hotmail.com>*Date*: Sun, 8 Apr 2007 05:08:22 -0400 (EDT)

Hi! I have to find the best parameter "k" with witch function sd[k]->minimum. I do that with FindMinimum. "sd" if a function that calculates the standard deviation from my experimental and model data. The model data is obtained from the mathematical model, first order differential equation...which I solve using NDsolve. The problem is that I cant make NDSolve work under FindMinimum. Something like this: First, I define function that hace to solve the equation c'[t] == -k c[t], where "k" is a variable. This gives me model data later on. I define it as a function cause I dont know the value of "k" yet. Then I define another function which calculates the standard deviation: sd[k_]:= function(model data, experimental data) Still I have no concrete results. Then I use FindMiniumm for finding the "k" that gives the smallest Standard Deviation FindMinimum[sd[k], {k, 0.04}] And her is the problem, I cant make this combination to work .... help please? Many thanks!