Apologies if this problem has been tackled. Searched the forums and couldn't find anything.
I'm trying to produce a simple scatterplot (with points representing means of different classes) for 2 variables (x and y). However, I would like to add error bars or std lines to the points (extending parallel to the x-axis in 2 directions). Something almost exactly like Exaple 2 on this page (not related to my work; I found it on Google):