如何获得基本图形绘图。通过arrangeGrob与他人结合的新手?

plot.new() 等:

p1 <- generate_ggplot1(...)
p2 <- generate_ggplot2(...)
p3 <- generate_ggplot3(...)

# how to get hold of the plot output and make it available as 
# p4 for arrangeGrob?
plot.new()
...

final <- gridExtra::arrangeGrob(p1, p2, p3, p4, layout_matrix = rbind(c(1,2), c(3,4)), widths=c(7,7), heights=c(7,7))
ggplot2::ggsave(filename=output.file,plot=final,width=14,height=14)

ggplot2