Hi All, I have two questions:
I am computing a linear regression model with 0 as Intercept. Well, I would like the sum of my predicted values be equal to a constant and therefore analyze if my coefficients are significatively different using or not this constraint. Does anyone know how I can constrain my model in a such way? Here is the code: data<-read.table ("input.txt", header=T, dec=".", sep="\t"); attach(data) lm <-lm(pop ~ ag + sav + mf -1, data=data) pred <- predict(lm) sum(pred) So I want to constrain my sum (pred) to be equal to C, with C=sum(pop) My second question is: is it possible to make the same constraint BUT with C as a vector of values? Let's say If I have 5 observations in 'data', with 'pop' as the first column. I want to compute the same model as above with a 'vector' of constraints. In that case, C=xi (with i from 1 to 3) x1 = sum (data[c(2,4), 1]) x2 = sum(data [c(1,3), 1]) x3 = data[5,1] Thanks in advance -- Any help is welcome! Jean-Paul Kibambe ______________________________________________ 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.