Hi R users I have a 1000 * 11 matrix (or data.frame). The first 10 columns consist of 0 or 1 (i.e., binary data) and the last column consists of real values. I would like to run a logistic regression with the first binary column as a dependent variable, and the second binary column and the last real value column as independent variables. After this, I save 'Z' value for the binary independent variable. Then, with the first binary column as a dependent variable, and the third binary column and the last real value column as independent variables. After this, I saved 'Z' value for the binary independent variable, keeping doing this ... Here is my simple R codes logistic.z.value <-c() for (i in 1:9) { for (j in (i+1):10) { model <- glm(X[,i] ~ X[,11] + X[,j], family=binomial(logit)) logistic.z.value <- append(logistic.z.value,coef(summary(model))[3,3]) } } I would like to avoid using 'for' loop command. Is there any way for me to use some fast codes instead of using 'for' loop? Many thanks Taka, _________________________________________________________________ Stay in touch with old friends and meet new ones with Windows Live Spaces