Hi, names(fit) fit$coefficients[[2]] <- 100
-- Henrique Dallazuanna Curitiba-Paraná-Brasil 25° 25' 40" S 49° 16' 22" O On 28/08/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote: > > Dear all, > > I would like to use predict.lm() with an existing lm object but with new > arbitrary coefficients. I modify 'fit$coef' (see example below) "by hand" > but the actual model in 'fit' used for prediction does not seem to be > altered (although fit$coef is!). > > Can anyone please help me do this properly? > > Thanks in advance, > > Jérémie > > > > > dat <- data.frame(y=c(0,25,32,15), x=as.factor(c(1,1,2,2))) > > fit <- lm(y ~ x, data=dat) > > fit > > Call: > lm(formula = y ~ x, data = dat) > > Coefficients: > (Intercept) x2 > 12.5 11.0 > > > fit$coef[[2]] <- 100 > > dat.new <- data.frame(x=as.factor(c(1,2,1,2))) > > predict.lm(fit, dat.new) > 1 2 3 4 > 12.5 23.5 12.5 23.5 > > fit > > Call: > lm(formula = y ~ x, data = dat) > > Coefficients: > (Intercept) x2 > 12.5 11.0 > > > fit$coef > (Intercept) x2 > 12.5 100.0 > > > > > > Jérémie Lebrec > Dept. of Medical Statistics and Bioinformatics > Leiden University Medical Center > Postzone S-05-P > P.O. Box 9600 > 2300 RC Leiden > The Netherlands > [EMAIL PROTECTED] > > ______________________________________________ > R-help@stat.math.ethz.ch 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. > [[alternative HTML version deleted]]
______________________________________________ R-help@stat.math.ethz.ch 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.
