RE: Intermediate Evaluation in FindMinimum

*To*: mathgroup at smc.vnet.net*Subject*: [mg86657] RE: [mg86617] Intermediate Evaluation in FindMinimum*From*: "Ausman, Kevin" <ausman at okstate.edu>*Date*: Sun, 16 Mar 2008 04:40:28 -0500 (EST)*References*: <200803130933.EAA01644@smc.vnet.net> <200803150810.DAA15236@smc.vnet.net> <2003.98.212.159.172.1205630116.squirrel@webmail.wolfram.com>

> Your chiSquare is having trouble when passed something it cannot fully > evaluate. Instead try: > > chiSquare[xpt : {_?NumericQ ..}, mdl : {_?NumericQ ..}] := > chiSquare[xpt, mdl] = Total[(xpt - mdl)^2] > > Daniel Lichtblau > Wolfram Research I was afraid that was going to be the suggestion. Unfortunately, when I do that I cannot use the Levenberg-Marquardt method (FindMinimum doesn't recognize chiSquare as being of the appropriate format), and the other methods don't seem to converge well for my data/model combination. I tried to find a way to specify the residuals manually to force it to use Levenberg-Marquardt, but then I end up with the same problem that I had when chiSquare wasn't doing the parameter-checking. I will go back to my earlier plan of writing up the full problem and posting that instead of a simplified version. Hopefully I will have that put together (and documented) within a day or so. Kevin Ausman

**References**:**LevenbergMarquardt***From:*"Ausman, Kevin" <ausman@okstate.edu>

**Intermediate Evaluation in FindMinimum***From:*"Ausman, Kevin" <ausman@okstate.edu>