r - ggbiplot - 改变标签的颜色

Question

默认情况下，ggbiplot 函数给出一个带有红色箭头和黑色单位标签的负载图：

library(ggbiplot)
data("USArrests")
us <- princomp(USArrests)
ggbiplot(us, labels = rownames(us$scores))

是该代码的结果

如何更改这些标签的颜色，以及它们的大小或字体？

Answer 1

library(ggbiplot)
library(grid)
data("USArrests")
us <- princomp(USArrests)

# Cut the third score into 4 intervals using quantiles
cols <- cut(us$scores[,3], quantile(us$scores[,3], probs=seq(0,1,0.25)), include.lowest=T)

# Change label colors using the "group" option
# Change label font size using the "label.size" option
p <- ggbiplot(us, labels = rownames(us$scores), groups=cols, labels.size=4)

# Change label font family 
g <- ggplotGrob(p)
g$grobs[[6]]$children[[4]]$gp$fontfamily <- "mono"
grid.draw(g)

要整体更改标签颜色：

p <- ggbiplot(us, labels = rownames(us$scores), groups=1, labels.size=4) +
     theme(legend.position = "none")

# Change label colors 
g <- ggplotGrob(p)
g$grobs[[6]]$children[[4]]$gp$col <- "#FF9900"
grid.draw(g)