r facet_wrap不规则数量的地块，x轴中心底部地块标题

Question

我的facet_wrap地块数量不平衡，这意味着我最终只有一个地块。我希望这个情节能够集中在X轴标题上，但一直没有弄清楚。感谢任何帮助。

简单的例子来说明我的问题而努力着：

library(ggplot2) 
p <- ggplot(head(diamonds, 50), aes(x = depth, y = price)) + 
    geom_point() 

p <- p + facet_wrap(~color, scales = "free", ncol = 3) 

Answer 1

你可以在gtable洗牌周围的东西;不幸的是，名字出现有些不一致

g <- ggplotGrob(p) 

g$layout[grepl("panel-3-1", g$layout$name), c("l","r")] <- g$layout[grepl("panel-2-2", g$layout$name), c("l","r")] 
g$layout[grepl("axis-l-3-1", g$layout$name), c("l","r")] <- g$layout[grepl("axis-l-2-2", g$layout$name), c("l","r")] 
g$layout[grepl("axis-b-1-3", g$layout$name), c("l","r")] <- g$layout[grepl("axis-b-2-2", g$layout$name), c("l","r")] 
g$layout[grepl("strip-t-1-3", g$layout$name), c("l","r")] <- g$layout[grepl("strip-t-2-2", g$layout$name), c("l","r")] 

grid.newpage() 
grid.draw(g)