有没有办法为 R 更改 pdp package 中的 header 颜色？

Question

Is it possible to change the header colour of plots in the pdp package for R? I would like the colour to be lightgrey. You can remove the colour of the pdp plot individually, but if I want to arrange them in a grid the colour returns back to default. For an example see below. Thanks in advance.

library(pdp)
library(grid)
library(gridExtra)

df <- data.frame(v1=rnorm(100), 
           v2=as.factor(sample(c("A","B","C"), 100, T)),
           v3=rlnorm(100))

mod    <- glm(v1~v2+v3, data=df)
modpdp <- pdp::partial(mod, grid.resolution = 10, pred.var = c("v2", "v3"))
p1     <- pdp::plotPartial(modpdp, trellis.par.set(strip.background=list(col="lightgrey")))
p2     <- pdp::plotPartial(modpdp, trellis.par.set(strip.background=list(col="lightgrey")))

grid.arrange(arrangeGrob(p1), arrangeGrob(p2))

Answer 1

It's a bit of a strange system. You need to pass a strip = argument which itself takes the output of a lattice::strip.custom call. It is inside the call to strip.custom where you set the colour using bg =

library(pdp)
library(grid)
library(gridExtra)
library(lattice)

df <- data.frame(v1 = rnorm(100),
                 v2 = as.factor(sample(c("A", "B", "C"), 100, T)),
                 v3 = rlnorm(100))


mod    <- glm(v1 ~ v2 + v3, data = df)
modpdp <- partial(mod, grid.resolution = 10, pred.var = c("v2", "v3"))
p1     <- plotPartial(modpdp, strip = strip.custom(bg = "lightgrey"))
p2     <- plotPartial(modpdp, strip = strip.custom(bg = "lightgrey"))

grid.arrange(arrangeGrob(p1), arrangeGrob(p2))

^{Created on 2020-05-25 by the reprex package (v0.3.0)}