cowplot_help

dat <- data.frame(a=c(1,2,3),
            b=c(4,5,6))


plota <- ggplot(data=dat,
                aes(x=a, y=b))+
          geom_point()+
          theme(axis.title.y = element_blank())


plotb <- ggplot(data=dat,
                aes(x=a, y=b))+
  geom_point()


masterplot <- cowplot::plot_grid(plota, plota,
                                 plotb, plota,
                                 plota, plota,
                                 nrow=3, align="v")