🚀 go-pugleaf

In article <1992Sep3.064230.42744@kuhub.cc.ukans.edu> jeff@kuhub.cc.ukans.edu (Jeff Bangert) writes:
>A chemist has asked me to solve a problem: she has data and a model
>which is to be fit by 'least squares'.  It looks like non-linear
>regression, except that:

>    1. the model has two equations
>    2. both are non-linear
>    3. there are parameters common to the two equations.

>I would like to know:

>    1. is there a 'standard' method for solving this problem?
>    2. is there literature in stat or chemistry which I could read?

To use a reasonable statisical approach, you should set up your probablity
model, and carefully assess your assumptions.  Then set up at least a 
reasonable approximation to the likelihood function, and do whatever
processing your assumptions call for.

I would not expect any package to handle this well.  Numerical analysis
is an art.
-- 
Herman Rubin, Dept. of Statistics, Purdue Univ., West Lafayette IN47907-1399
Phone: (317)494-6054
hrubin@pop.stat.purdue.edu (Internet, bitnet)  
{purdue,pur-ee}!pop.stat!hrubin(UUCP)