Reputation: 371
I have this dataframe as an example:
>mydata <- rbind(data.frame(Col1 = rnorm(2*1000),Col2 =rep(c("A", "C"), each=1000),Col3=factor(rep(c("YY","NN"), 1000))),data.frame(Col1 = rnorm(1000),Col2 =rep(c("B")),Col3=factor(rep(c("YY","YN"), 500))))
That looks like:
>head(mydata)
Col1 Col2 Col3
1 -0.1213684 A YY
2 0.1846364 A NN
3 0.4028003 A YY
4 1.4065677 A NN
5 -0.8669333 A YY
6 0.3295806 A NN
Being Col3 of factor type with 3 levels: NN YY YN
I want to make a boxplot using lattice bwplot and assign to each level a specific color:
# NN:
red=rgb(249/255, 21/255, 47/255)
# YN:
amber=rgb(255/255, 126/255, 0/255)
# YY:
green=rgb(39/255, 232/255, 51/255)
Using bwplot function:
pl<-bwplot(mydata$Col1~mydata$Col3 | mydata$Col2,data=mydata,
ylab=expression(italic(R)),panel=function(...)
{panel.bwplot(...,groups=mydata$Col3, fill=c(red,amber,green))})
That results in the following Figure:
Clearly colors are not related to the levels in my dataframe as YY box is not always green. Is there a way to assign YY:green, NN:red and YN:amber?
Upvotes: 5
Views: 2734
Reputation: 162321
Here is what I'd do:
## Create a named vector of fill colors
red <- rgb(249/255, 21/255, 47/255) # NN:
amber <- rgb(255/255, 126/255, 0/255) # YN:
green <- rgb(39/255, 232/255, 51/255) # YY:
fillCols <- c(NN=red, YN=amber, YY=green)
## Create a panel function that, with access to the subset of points plotted
## in the current panel, picks out the levels/colors that will be needed
myPanel.bwplot <- function(x=x, y=y, ...) {
fill <- fillCols[intersect(levels(x), unique(x))]
panel.bwplot(x=x, y=y, ..., groups=Col3, fill=fill)
}
## Plot away
bwplot(Col1 ~ Col3 | Col2, data = mydata, panel = myPanel.bwplot)
Upvotes: 7