Hi there, I was wondering if you could help me to write the following procedure. I need to plot x against y. The x is read directly from a file. The y is delta from power.t.test: y <- as.vector(power.t.test(n=4, sd =z, power = 0.8)$delta), where z values are also read from the file. Thank you for your help. Pawel Pawel Michalak Assistant Professor Department of Biology University of Texas at Arlington