Sorry, just realized that there was a typo in the following code of my original post. The correct code is as shown below (corrected 'data=swtop16' to 'data=DF'):
sales <- xyplot(pct_inv_left ~ week_num|sku_num, data=DF,type = "l",lwd=2,panel = function(...) { panel.abline(h = 75, lty = 2) panel.xyplot(...) }) Thanks, -Girish -- View this message in context: http://r.789695.n4.nabble.com/lattice-xyplot-Help-needed-in-help-in-customizing-the-panel-abline-function-tp3079656p3079666.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.