That's pretty standard. Some call it "response surface analysis". Of course you need to check assumptions like homoscedasticity on the log scale, etc.
It's not really an R question, specifically; so stats.stackexchange.com is a better avenue for more detailed discussions. As far as R goes, you just need to be aware that, due to an ancien misfeature, terms like x^2 need to be protected by writing I(x^2). -pd On 23 Feb 2016, at 11:42 , <james.fo...@diamond.ac.uk> <james.fo...@diamond.ac.uk> wrote: > Dear R community, > this is probably a well-known topic to some of you, but I am not well into it > and would like some clarifications or even jus some suggestions. > > I have a quadratic scalar field: > > F(x,y)=K*exp(-(a*x^2+b*y^2+c*x*y)) > > I also have a random set of positive x,y values and related F(x,y) values. > It seems reasonable to estimate the parameters K, a, b, c with a linear > regression, > using the log of both sides of the equation. > > What worries me, though, is the interaction term, c*x*y. > > Are there well-known issues on the application of linear regression to cases > like this one? > > Thanks in advance for your answers. > > James > > -- > This e-mail and any attachments may contain confidential...{{dropped:16}} > > ______________________________________________ > R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. -- Peter Dalgaard, Professor, Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Office: A 4.23 Email: pd....@cbs.dk Priv: pda...@gmail.com ______________________________________________ R-help@r-project.org mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.