Hello, thanks for the two replies. The following code worked as expected: pos <- 1:10 lab <- letters[pos] ll <- parse(text = paste(pos,"*phi[",lab,"]",sep = "")) xyplot(1:10~1:10,scales = list(x = list(labels = ll,at = 1:10))) Best regards, Albart -----Original Message----- From: Coster, Albart Sent: Tue 7/7/2009 1:27 PM To: r-help-request at r-project.org Subject: Mathematical annotation axis in lattice Dear list, making mathematical expressions in plots is not difficult: expression(phi[1]) for example. At this moment I am stuck in creating a vector of expressions: pos <- 1:10 lab <- letters[pos] Now, I would like to create a vector of expressions which I could use for labeling the x-axis of a lattice plot. ll <- as.expression(paste(pos," phi[",lab,"]",sep = "") xyplot(1:10~11:10,scales = list(x = list(labels = ll,at = 1:10))) does not work. I read about the function substitute, but that did not solve it. Could you recommend me how I should do this? Thanks in advance, Albart Coster Wageningen Universiteit Netherlands