How to include a constraint in NonlinearFit?
- To: mathgroup at smc.vnet.net
- Subject: [mg44647] How to include a constraint in NonlinearFit?
- From: "L. Vergara" <lvergara at lauca.usach.cl>
- Date: Wed, 19 Nov 2003 04:59:12 -0500 (EST)
- Sender: owner-wri-mathgroup at wolfram.com
Hi, thanks to Curt Fisher, now I know how to to fit an array of preexisting data with a function defined by NDSolve (see http://tinyurl.com/v0n1) In the example I mentioned in my previous message, the function to be fitted is f[y_,a_,b_] :=NDSolve[x'[y] == (y^2/2 + a y + b)/Sqrt[1 -(y^2/2 + a y + b)^2], x[0] == .6}, y, {y, 0, 1.5}]; Here there is a constraint that must be satisfied: Abs[(y^2/2 + a y +b)^2]<1. Do you know how include this into NonlinearFit (or perhaps better, into NDSolve)? Thanks! Lautaro Vergara