不幸的是,我看不出这是怎么可能的。
首先,它不适用于gridExtra
,因为arrangeGrob
对TableGrob
对象进行操作:
> ggplotGrob(qplot(1:100))
stat_bin: binwidth defaulted to range/30. Use 'binwidth = x' to adjust this.
TableGrob (6 x 5) "layout": 8 grobs
z cells name grob
1 0 (1-6,1-5) background rect[plot.background.rect.3349]
2 3 (3-3,3-3) axis-l absoluteGrob[GRID.absoluteGrob.3341]
3 1 (4-4,3-3) spacer zeroGrob[NULL]
4 2 (3-3,4-4) panel gTree[GRID.gTree.3329]
5 4 (4-4,4-4) axis-b absoluteGrob[GRID.absoluteGrob.3335]
6 5 (5-5,4-4) xlab text[axis.title.x.text.3343]
7 6 (3-3,2-2) ylab text[axis.title.y.text.3345]
8 7 (2-2,4-4) title text[plot.title.text.3347]
object的内部表示ggpairs
只包含要调用的方法,而不是实际的 grobs:
> str(p1$plots)
List of 9
$ : chr "ggally_diagAxis(ggally_data, ggplot2::aes(x = var1))"
$ : chr "ggally_cor(ggally_data, ggplot2::aes(x = var2, y = var1))"
$ : chr "ggally_cor(ggally_data, ggplot2::aes(x = var3, y = var1))"
$ : chr "ggally_points(ggally_data, ggplot2::aes(x = var1, y = var2))"
$ : chr "ggally_diagAxis(ggally_data, ggplot2::aes(x = var2))"
$ : chr "ggally_cor(ggally_data, ggplot2::aes(x = var3, y = var2))"
$ : chr "ggally_points(ggally_data, ggplot2::aes(x = var1, y = var3))"
$ : chr "ggally_points(ggally_data, ggplot2::aes(x = var2, y = var3))"
$ : chr "ggally_diagAxis(ggally_data, ggplot2::aes(x = var3))"
构建实际 grobs 的整个工作由GGally:::print.ggpairs
. 看一下源代码,你会看到grid.newpage()
多个popViewport
s 和pushViewport
s。这意味着即使是低级grid
方法(例如此处描述的)也不适用,因为您的grid
结构将被GGally:::print.ggpairs
.
当然,总有办法。修改源代码始终是一种选择,尽管我相信这对您的任务来说是一条漫长而艰难的道路。如果有人能想出一个简单的解决方法,我会很高兴被证明是错误的。