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Non linear modeling

2 messages · Liaw, Andy, ronggui

#
AFAIK most model fitting techniques will only deal with additive errors, not
multiplicative ones.  You might want to try fitting:

log(y-x) = a*x + e

which is linear.

Andy
#
then is the nls function can deal the problem as Guillaume STORCHI mentioned in the last post? [X<-nls(y~x+exp(a*x)*eps, data=,start=list(a=,eps=))]
or just can solve the problem as:log(y-x) = a*x + e?



On Fri, 18 Mar 2005 08:56:38 -0500
"Liaw, Andy" <andy_liaw at merck.com> wrote: