In the chapter Graphics for Communication in R for Data Science, @hadley discusses figure sizing and gives some advice to keep consistency in the document. I've been following the tips and I think they work very well when you don't have many panels. This time, however, I am using a facet_wrap to create a 4-row plot. I would like each row/panel to have the same aspect as a simple plot. More specifically: assume I have set fig.width=6, fig.asp=0.618 and out.with="70%" as suggested, how do I obtain this figure sizing for each panel of my plot?