Hi Robert, you can exclude the intercept by including "-1" in the formula:
value <- as.numeric(runif(20)<.4) ppm <- rnorm(20) glm(value~ppm-1,family=binomial) HTH Stephan > Dear Statisticians, > > I would like to analyse my data with a GLM with binomial error distribution > and logit link function. The point is that I want a model fitted without > intercept, i.e. the fitted curve should start at y=0.5 for x=0. > > I tried it with the following code: > > glm(value~0+ppm, binomial) > > Does this code yield the correct model or is there another possibility? I?d > appreciate it very much if you could help me out with this. I attached some > example data. > > Thanks & all the best > > Robert -- ______________________________________________ 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.
