Keep or set the ratio between text labels and size of plot in grid.arrange

Question

I am trying to arrange 2 plots created using ggplot2 and would like the plots to be the size of a square and one next to the other, with the common legend next

Answer 1

I'm not sure what you expect for the output, but try this,

g = arrangeGrob(
  arrangeGrob(p1 + coord_fixed() + theme(legend.position="none"),
              p2 + coord_fixed() +theme(legend.position="none"),
              main = textGrob("The main figure title is also small and hard to align left",  x=0, hjust =0, vjust=1, gp = gpar(fontsize = 22)), nrow=1), 
             mylegend, widths=unit.c(unit(1, "npc") - sum(mylegend$width), 
                                     sum(mylegend$width)), nrow=1)

ggsave("layout.pdf", g, width=12, height=5)