[R] Arranging ggplot2 objects with ggplotGrob()

[H]

I am trying to arrange two plots vertically, ie plot 2 below plot 1, where I want the plots to align columnwise but have a height ratio of eg 3:1.

My attempts so far after consulting various webpages is that the following code aligns them columnwise correctly but I have, so far, failed in setting the relative heights...

g2<-ggplotGrob(s)
g3<-ggplotGrob(v)
g<-rbind(g2, g3, size = "first")
g$widths<-unit.pmax(g2$widths, g3$widths)

what would the appropriate statement for the relative heights to add here be?

grid.newpage()
grid.draw(g)

Thank you!