Marc Bernard <[EMAIL PROTECTED]> wrote: > Dear All, > I would be grateful if you can help me. My problem is the following: > I have a data set like:
> ID time X1 X2 > 1 1 x111 x211 > 1 2 x112 x212 > 2 1 x121 x221 > 2 2 x122 x222 > 2 3 x123 x223 > where X1 and X2 are 2 covariates and "time" is the time of observation and ID > indicates the cluster. > I want to merge the above data by creating a new variable "X" and "type" as > follows: > ID time X type > 1 1 x111 X1 > 1 2 x112 X1 > 1 1 x211 X2 > 1 2 x212 X2 > 2 1 x121 X1 > 2 2 x122 X1 > 2 3 x123 X1 > 2 1 x221 X2 > 2 2 x222 X2 > 2 3 x223 X2 > Where "type" is a factor variable indicating if the observation is related to > X1 or X2... Say your original data is in dataframe df, then this might do what you want: R> newdf <- rbind(df[, 1:3], df[, c(1, 2, 4)]) R> names(newdf)[3] <- "X" R> newdf$type <- substr(c(df[[3]], df[[4]]), 1, 2) Cheers, -- Sebastian P. Luque ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html