estimating parameters for model of 3 differential equations

Hi all,

I've been having a lot of trouble figuring out the best way to estimate parameters in Matlab. Does anyone have suggestions on the best function? I was able to estimate parameters for a model with only one differential equation using lsqcurvefit but I haven't been able to figure out how to use lsqcurvefit or anything else to estimate parameters for a model with 3 differential equations. Any help would be much appreciated!

Answer 1

[Rajiv Singh]

One convenient way of handling estimating parameters of ODEs is facilitated by System Identification Toolbox. Some links:

http://www.mathworks.com/help/toolbox/ident/ug/bqs6lf8.html

In: http://www.mathworks.com/products/sysid/demos.html,

see: "Tutorials on Nonlinear Grey Box Model Identification"

[LS]

Hi! Thanks very much for the help - I really appreciate it! I've been reading a lot about this and have tried it out with some code. I don't get any errors but I can't tell if it's working. It's been running on my computer for about 15 hours and I think it's still going...anyways, I've posted the code in a separate question because posting it here in a comment would make it very hard to read. The new question is here:

http://mathworks.com/matlabcentral/answers/12622-nonlinear-grey-box-modeling-code-really-slow-or-not-working

Thank you so much again for your help!!