Fitting multiple nonlinear equations to unequal length datasets

*To*: mathgroup at smc.vnet.net*Subject*: [mg29789] Fitting multiple nonlinear equations to unequal length datasets*From*: "Dr J. Satherley" <js1 at liverpool.ac.uk>*Date*: Tue, 10 Jul 2001 20:25:28 -0400 (EDT)*Sender*: owner-wri-mathgroup at wolfram.com

Dear All I just been making quite extensive use of the mrfit package from Mathsource. Its a very nice little resource making it rather easy to do multiple non-linear equation fits to datasets where there are some common parameters in the equations. However, it seems to assume that the number of data points per set of data are all equal, i.e for every line of the data: {{x1, x2,..,xn,.{y1,y2,...,yn}} in the dataset they all have the same value of n. I have a problem in which some data points are missing i.e there are some lines where the number of x and y values are less than n compared to the other lines in the dataset. Does anyone know: 1) Of a clever way to get mrfit to recognise such a dataset? 2) If there is a symbol that can be added where the data are missing so that the mrfit function simply ignores the missing points? 3) If I have to resort to writing my own codes with FindMinimum etc. to overcome my problem? Cheers John ************************************************************* Dr J. Satherley Department of Chemistry University of Liverpool Liverpool L69 7ZD United Kingdom tel: +44(0)151 794 3530 fax: +44(0)151 794 3588 (Dept.) email: js1 at liv.ac.uk *************************************************************