Well, this is your second post on the same topic, your first having received no response. So you should suspect something is amiss and reconsider before continuing, don't you think?
1. I, for one, was not able to make any sense of your query. You do not appear to understand regression, so I would suggest you spend time with a local statistical resource before continuing with online posts.If my understanding of your misunderstanding is correct, you need to comprehend basics. If not,apologies. 2. Have you read An Introduction to R (ships with R) or an online R tutorial of your choice? If not, do so before posting here further. We expect minimal efforts of posters to solve their own problems before posting. Again, apologies if I err. Cheers, Bert Bert Gunter Genentech Nonclinical Biostatistics (650) 467-7374 "Data is not information. Information is not knowledge. And knowledge is certainly not wisdom." H. Gilbert Welch On Sun, Apr 13, 2014 at 8:08 PM, Edson Tirelli <ed.tire...@gmail.com> wrote: > I am quite new to R and I am having trouble figuring out how to select > variables in a multivariate linear regression in R. My google-fu also > did not find anything. > > Pretend I have the following formulas: > > P = aX + bY > Q = cZ + bY > > I have a data frame with column P, Q, X, Y, Z and I need to find a, b and c. > > If I do a simple multivariate regression: > > result <- lm( cbind( P, Q ) ~ X + Y + Z - 1 ) > > It calculates a coefficient for "c" on P's regression and for "a" on > Q's regression. > > If I calculate the regressions individually then "b" will be different > in each regression. > > How can I select the variables to consider in a multivariate > regression? I.e., how do I tell R to ignore cZ when calculating P, and > ignore aX when calculating Q? > > Thank you, > Edson > > ______________________________________________ > 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.
