我想在ggplot2
的分面图上添加一个方面标题作为条带。我的MWE抛出一个错误。任何帮助将受到高度赞赏。感谢
library(ggplot2)
library(gtable)
p <- ggplot(mtcars, aes(mpg, wt)) + geom_point()
p <- p + facet_grid(. ~ cyl)
# get gtable object
Plot1 <- ggplot_gtable(ggplot_build(p))
# add label for top strip
Plot1 <- gtable_add_rows(Plot1, Plot1$heights[[3]], 2)
Plot1 <- gtable_add_grob(Plot1,
list(rectGrob(gp = gpar(col = NA, fill = gray(0.5))),
textGrob("Cyl", gp = gpar(col = gray(1)))),
3, 4, 3, 10, name = paste(runif(2)))
# add margins
Plot1 <- gtable_add_rows(Plot1, unit(1/8, "line"), 2)
# draw it
grid.newpage()
print(grid.draw(Plot1))
答案 0 :(得分:16)
修改更新到ggplot 3.0.0版
我觉得你很亲密。 add grob命令中的行号和列号错误。你的新条带跨越5到9列;也就是说,在add grob命令中将10更改为9。
library(ggplot2)
library(gtable)
library(grid)
p <- ggplot(mtcars, aes(mpg, wt)) + geom_point()
p <- p + facet_grid(. ~ cyl)
z <- ggplotGrob(p)
# New strip at the top
z <- gtable_add_rows(z, z$height[7], pos = 6) # New row added below row 6
# Check the layout
gtable_show_layout(z) # New strip goes into row 7
# New strip spans columns 5 to 9
z <- gtable_add_grob(z,
list(rectGrob(gp = gpar(col = NA, fill = "gray85", size = .5)),
textGrob("Number of Cylinders", gp = gpar(cex = .75, fontface = 'bold', col = "black"))),
t=7, l=5, b=7, r=9, name = c("a", "b"))
# Add small gap between strips - below row 6
z <- gtable_add_rows(z, unit(2/10, "line"), 7)
# Draw it
grid.newpage()
grid.draw(z)
或者,在右边添加一个新的条带:
library(ggplot2)
library(gtable)
library(grid)
p <- ggplot(mtcars, aes(mpg, wt)) + geom_point()
p <- p + facet_grid(cyl ~ .)
z <- ggplotGrob(p)
# New strip to the right
z <- gtable_add_cols(z, z$widths[6], pos = 6) # New column added to the right of column 6
# Check the layout
gtable_show_layout(z) # New strip goes into column 7
# New strip spans rows 7 to 11
z <- gtable_add_grob(z,
list(rectGrob(gp = gpar(col = NA, fill = "gray85", size = .5)),
textGrob("Number of Cylinders", rot = -90,
gp = gpar(cex = .75, fontface = 'bold', col = "black"))),
t=7, l=7, b=11, r=7, name = c("a", "b"))
# Add small gap between strips - to the right of column 6
z <- gtable_add_cols(z, unit(2/10, "line"), 6)
# Draw it
grid.newpage()
grid.draw(z)