Thanks for the suggestion, but I think I might not have made myself very clear. I actually have about 2000 sets of M, D, O, and S, so it's probably not efficient to make each a separate set and then index. I've put everything into a data frame, so I would like to test how well the regression fit for each group, which consists of 5 sets of M, D, O, and S. Since I'll need to test it for about 400 groups, I thought a for loop might be necessary. Any suggestions? I'm just not especially sure how to do the for loop.
Daniel Malter wrote:
for a beginner, it's probably even easier to it by hand if it is just five datasets. bind the 5 datasets together in one dataset and create and index variable (1 to 5) for each of the observations according to the dataset the obersvation comes from then run five regressions using reg1=lm(M~D+O+S,subset=c(index==1)) . . . reg5=lm(M~D+O+S,subset=c(index==5)) and then predict from each regression predict(reg1,newdata=data.frame(D,O,S)) . . . predict(reg5,newdata=data.frame(D,O,S)) You can then assess how well the prediction from each of the datasets fits the respective other datasets... Daniel ------------------------- cuncta stricte discussurus ------------------------- -----Urspr?ngliche Nachricht----- Von: r-help-bounces at r-project.org [mailto:r-help-bounces at r-project.org] Im Auftrag von Rbeginner Gesendet: Sunday, July 19, 2009 9:49 PM An: r-help at r-project.org Betreff: [R] Re gression for loop test HELP! URGENT! Hi everyone! I'm new to R, and I'm stuck on a problem I don't know how to approach. I have calculated a regression in the form of M ~ D + O + S, and I would like to take this regression and test it with other samples, 5 at a time(5 meaning 5 set, each consisting M, D, O, and S of a specific date). I assume I'll need a for loop. Right now, My data of M, D, O, and S are all stored in separate txt files, but should I just put them into a table or something? And then how would I calculate the error of how well the test samples fit the original regression? This is for my internship, so it's very urgent. THANKS A LOT!!!!! RBeginner -- View this message in context: http://www.nabble.com/Regression-for-loop-test-HELP%21-URGENT%21-tp24562766p 24562766.html Sent from the R help mailing list archive at Nabble.com.
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