HI, I hope this helps you,
set.seed(1) dat1<-data.frame(X1=rnorm(25,15),X2=rnorm(25,5),X3=runif(25,0.4),X4=rnorm(25,12),Y=rnorm(25,35)) ColNam<-names(dat1) ColNam #[1] "X1" "X2" "X3" "X4" "Y" ColNam<-ColNam[!ColNam %in% "Y"] n<-length(ColNam) ColNam #[1] "X1" "X2" "X3" "X4" id1<-unlist(lapply(1:n,function(x)combn(1:n,x,simplify=F)),recursive=F) f1<-lapply(id1,function(x) paste("Y~",paste(ColNam[x],collapse="+"))) res1<- lapply(f1,function(x) lm(as.formula(x),data=dat1)) summary(res1[[1]]) Call: lm(formula = as.formula(x), data = dat1) Residuals: Min 1Q Median 3Q Max -1.46344 -0.78252 -0.08563 0.68324 1.49788 Coefficients: Estimate Std. Error t value Pr(>|t|) (Intercept) 34.26057 3.03804 11.277 7.56e-11 *** X1 0.05828 0.19991 0.292 0.773 --- Signif. codes: 0 ‘***’ 0.001 ‘**’ 0.01 ‘*’ 0.05 ‘.’ 0.1 ‘ ’ 1 Residual standard error: 0.9305 on 23 degrees of freedom Multiple R-squared: 0.003682, Adjusted R-squared: -0.03964 F-statistic: 0.085 on 1 and 23 DF, p-value: 0.7732 A.K. ----- Original Message ----- From: zel7223 <jmichel.for...@hotmail.fr> To: r-help@r-project.org Cc: Sent: Thursday, August 9, 2012 9:28 AM Subject: [R] All combinations possible in a mutliple regression Hi, I want to use four independent variables to predict the output of one dependent variable using a linear model lm. I want to compare all possible combinations of the 4 independent variables, including singles, pairs and triples. I was thinking of using the AIC test to compare all models and pick the best one. The model looks like this : lm(Y ~ X1 + X2 + X3 + X4) Thanks for your help Cheers Jean-Michel Fortin UOttawa -- View this message in context: http://r.789695.n4.nabble.com/All-combinations-possible-in-a-mutliple-regression-tp4639762.html Sent from the R help mailing list archive at Nabble.com. ______________________________________________ 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.