Set the height of the graphs y-axis in grid.arrange, but not of the entire plot area

Question

When using grid arrange I encountered the following problem : I want all my panels (a,b,c) to

Answer 1

You should use rbind instead of grid.arrange,

plots <- list(p_a, p_b, p_c)
grobs <- lapply(plots, ggplotGrob)
# for gridExtra < v2.3, use do.call(gridExtra::rbind.gtable, grobs)
# for gridExtra >= v2.3 use:
g <- do.call(gridExtra::gtable_rbind, grobs)

library(grid)
grid.newpage()
grid.draw(g)