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How to manually colour strips using function "useOuterStrips" in package "latticeExtra"?

I'd like to do a plot very similar to the one below. However I want to have a different color for each strip, e.g. sub1 in green, sub2 in blue, sub3 in red ... (the same for all seas1 to seas4). So far I did not succeed to do this.

I had a look at this post here: change background and text of strips associated to muliple panels in R / lattice but I did not manage to modify it to achieve what I want to have. I think this is due to using the function useOuterStrips.

I produced the figure with the following code using R version 3.2.0, latticeExtra_0.6-26 and lattice_0.20-31:

require(lattice)
require(latticeExtra)
cbPalette <- c("#999999", "#E69F00", "#56B4E9", "#009E73", "#F0E442", "#0072B2", "#D55E00", "#CC79A7")
mydat <- data.frame(response=rnorm(400,mean=1),
                p = factor(sample(rep(1:4,each=100))),
                sub = factor(rep(sprintf("sub%i",1:4),each=100)),
                seas=factor(rep(sprintf("seas%i",1:4),100)))
useOuterStrips(bwplot(response~factor(p)|factor(sub)+factor(seas),
                  data=mydat,par.settings = list(strip.background=list(col = c("skyblue","gold"))),
                  fill = cbPalette,xlab="xlab",ylab="ylab"))

Any help would be highly appreciated!

enter image description here

Solution

  • For future reference, this can be achieved through specifying a second function that handles the strips on the left-hand side. See argument strip.left in ?useOuterStrips.

    Building on top of the aforementioned SO post,

    ## set strip background colors
cbPalette = c(
  "#999999", "#E69F00", "#56B4E9", "#009E73" # top
  , "#F0E442", "#0072B2", "#D55E00", "#CC79A7" # left
)

## define core strip function
myStripStyle = function(which.panel, factor.levels, col, ...) {
  panel.rect(
    0, 0, 1, 1
    , col = col[which.panel]
    , border = 1
  )
  panel.text(
    x = 0.5
    , y = 0.5
    , lab = factor.levels[which.panel]
    , ...
  )
}

## and convenience functions for top ..
myStripStyleTop = function(which.panel, factor.levels, ...) {
  myStripStyle(
    which.panel
    , factor.levels
    , col = cbPalette[1:4]
  )
}

## .. and left strips
myStripStyleLeft = function(which.panel, factor.levels, ...) {
  myStripStyle(
    which.panel
    , factor.levels
    , col = cbPalette[5:8]
    , srt = 90 # and other arguments passed to `panel.text()`
  )
}

## assemble plot
useOuterStrips(
  bwplot(
    response ~ factor(p) | factor(sub) + factor(seas)
    , data = mydat
    , fill = cbPalette
  )
  , strip = myStripStyleTop
  , strip.left = myStripStyleLeft
)

    boxplot