Dear Joe, You need to use offset() lm(y ~ a + offset(b) + c)
Best regards, Thierry ---------------------------------------------------------------------------- ir. Thierry Onkelinx Instituut voor natuur- en bosonderzoek team Biometrie & Kwaliteitszorg Gaverstraat 4 9500 Geraardsbergen Belgium Research Institute for Nature and Forest team Biometrics & Quality Assurance Gaverstraat 4 9500 Geraardsbergen Belgium tel. + 32 54/436 185 thierry.onkel...@inbo.be www.inbo.be To call in the statistician after the experiment is done may be no more than asking him to perform a post-mortem examination: he may be able to say what the experiment died of. ~ Sir Ronald Aylmer Fisher The plural of anecdote is not data. ~ Roger Brinner The combination of some data and an aching desire for an answer does not ensure that a reasonable answer can be extracted from a given body of data. ~ John Tukey > -----Oorspronkelijk bericht----- > Van: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] > Namens JoeP > Verzonden: dinsdag 26 juli 2011 11:26 > Aan: r-help@r-project.org > Onderwerp: [R] help with regression > > Hi, > > I am trying to do a linear regression but I want one of my variables to not > generate a coefficient. E.g. what I want to do is fit for y=a+b+c but > forcing the > coefficient of b to be 1. Is this possible? > > I have been fitting y-b=a+c but I have found that when I recalculate y it is > not > close to the value. I have assumed that by fitting y-b then the y part has > become > insignificant. In case it makes a difference I have been using lm rather > than glm. > > Thanks in advance, > > Joe > > -- > View this message in context: http://r.789695.n4.nabble.com/help-with- > regression-tp3695245p3695245.html > Sent from the R help mailing list archive at Nabble.com. > > ______________________________________________ > R-help@r-project.org mailing list > 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. ______________________________________________ R-help@r-project.org mailing list 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.
