Contrast problem
Hi, I have a question regarding contrasts in linear models. I have a factor variable age with 4 levels, in the output of the linear model I want a coefficient for each level of age. I have made sure that age is a factor but am unsure how to put age into the model to ensure the model knows it is a factor an dto display all levels. I have tried doing fit<-lm(y~C(age)+sex.....) (the dot bits are the rest of the function which I have cut out as its not important here) but it only displays age as though it has one level what am I doing wrong and how can I get R to recognise its a factor? Thanks Jane ------------------------------------------------------ BA flight sale now at http://www.lycos.co.uk. Boston, ?129 rtn. including tax, Wednesday, 1pm