R：網格佈局標題

Question

我使用的是格包，以顯示圖的一個這樣的數組：

layout <- grid.layout(2, 4) 
pushViewport(viewport(layout = layout)) 
# print various plots 

是否有某種方式來指定整個網格佈局標題？

Answer 1

基於類似的SO問題

假人例如：Place title of multiplot panel with ggplot2

1. 首先創建一個佈局所需的行數的+ 1短一個用於標題：

   pushViewport(viewport(layout = grid.layout(3, 2, heights = unit(c(0.5, 5, 5), "null")))) 
   

2. 創建一些情節有：

   print(ggplot(mtcars, aes(hp)) + geom_histogram(), vp = viewport(layout.pos.row = 2, layout.pos.col = 1:2)) 
   print(ggplot(mtcars, aes(wt)) + geom_histogram(), vp = viewport(layout.pos.row = 3, layout.pos.col = 1)) 
   print(ggplot(mtcars, aes(mpg)) + geom_histogram(), vp = viewport(layout.pos.row = 3, layout.pos.col = 2)) 
   

3. 給top ro增加一個標題瓦特：

   grid.text("MAIN TITLE", vp = viewport(layout.pos.row = 1, layout.pos.col = 1:2)) 
   

從而造成：

Answer 2

的另一種方法：使用鹼情節

library(gridExtra) 
g = rectGrob() # dummy "plot" 
grid.arrange(g, g, g, g, ncol=2, top = "Main Title")