About the covariant
On Jun 27, 2011, at 10:02 PM, Lao Meng wrote:
Hi all,I have some questions about the covariants of regression. My target: To explore the trend of CD4 level through a period of time. Response variable: CD4 count Explanatory variable:time Also, the demology information is available,such as gender,occupation,income level... Q1,Are these variables of demology information called covariant? Q2,How can I correct the impact of "covariant" so that I can get the "corrected result" of CD4's change through the time period? Q3,How to treat the covariants in regression?I've looked up to many papers of R on regression,which treat the covariant in the same way as the Explanatory variable,like following: lm(CD4 ~ time + gender + income)
Yes that seems pretty standard practice. It does, of course, force the relationships to a) be linear and b) means that a single slope and intercept are estimated for each variable, neither of a} or b} assumptions may be true.
From above expression of regression,it's obvious that the response variables
and covariants are treated the same way,
In what sense are you making that claim? True they are both numeric, but what else are you saying?
David > but acturally > > they are totally different. > > > > Thanks for your help. > > My best. > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help at 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. David Winsemius, MD West Hartford, CT