lapply(1:4, function(i, x, y) {x[i,y[,1]]}, Z, index ) ## reproduces your results
sapply(1:4, function(i, x, y) {x[i,y[,1]]}, Z, index ) ## collapses your list into a set of columns ______________________________________________ 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.