如何更改 R 中 corrplot 中特定变量的字体颜色？

Question

How do I change the color of the font tl.col specific for certain variables like in the image?

Do I have to create a variable before? Or can you select columns within the command?

corrplot(cor(iris[,-5]), tl.col="black", tl.cex=0.8, tl.srt=70)

Answer 1

Try with this:

library (corrplot)
library(MASS)
library(calibrate)
data("iris")

corrplot(cor(iris[,-5]), cl.pos = "n", tl.pos = "n")  
textxy(0,1,labs=c("Petal.Width"),cex=0.8,offset=-0.2,col="blue")
textxy(0,2,labs=c("Petal.Length"),cex=0.8,offset=-0.2,col="blue")
textxy(4,5,labs=c("Petal.Width"),cex=0.8,offset=0,col="blue",srt=45)
textxy(3,5,labs=c("Petal.Length"),cex=0.8,offset=0,col="blue",srt=45)

textxy(0,3,labs=c("Sepal.Width"),cex=0.8,offset=-0.2,col="red")
textxy(0,4,labs=c("Sepal.Length"),cex=0.8,offset=-0.2,col="red")
textxy(2,5,labs=c("Sepal.Width"),cex=0.8,offset=0,col="red",srt=45)
textxy(1,5,labs=c("Sepal.Length"),cex=0.8,offset=0,col="red",srt=45)

Basically you have to remove the variable names displayed by corrplot and textxy creates labels. You have to set position, color..., it's a shortcut for your problem

Answer 2

tl.col takes a vector with colors for each variable. So you can set the color for each variable directly with the tl.col argument like this:

corrplot(cor(iris[,-5]), tl.col=c("red", "red", "blue", "blue"), tl.cex=0.8, tl.srt=70)

Alternatively you can define the colors within a function:

colors <- ifelse(grepl("Sepal", names(iris)[-5]), "red", "blue")
corrplot(cor(iris[,-5]), tl.col=colors, tl.cex=0.8, tl.srt=70)

# or 

corrplot(cor(iris[,-5]), tl.col=ifelse(grepl("Sepal", names(iris)[-5]), "red", "blue"),
tl.cex=0.8, tl.srt=70)