Hi, I'm trying to reshape my data set from wide to tall format for multilevel modeling. Unfortunately, the function I typically use (make.univ from the multilevel package) does not appear to work with unbalanced data frames, which is what I'm dealing with.
Below is an example of the columns of a data frame similar to what I'm working with: ID a1 a2 a4 b2 b3 b4 b5 b6 Below is what I want the columns to be after reshaping the data to long format: ID a b time Here is an example data frame that I want to reshape: ID <- c(1,2,3) a1 <- c(NA, rnorm(2)) a2 <- c(NA, rnorm(1), NA) a4 <- c(NA, rnorm(2)) b2 <- c(rnorm(2), NA) b3 <- rnorm(3) b4 <- NA b5 <- rnorm(3) b6 <- rnorm(3) mydata <- as.data.frame(cbind(ID,a1,a2,a4,b2,b3,b4,b5,b6)) What is the best way to do this efficiently with MANY variables with widely differing time ranges? Note that I will have to manually enter the time for a given measurement because in the wide format, the time is in the variable names. By the way, I have a fairly large data set, with some variables occurring at 2 time points and other variables occurring at 20 time points. Thanks for your help! -- View this message in context: http://r.789695.n4.nabble.com/Reshaping-data-from-wide-to-tall-format-for-multilevel-modeling-tp3796168p3796168.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.
