spplot: put labels on the map

Question

I seek help on how to change font size and font color for sp.text labels on the attached map—to avoid overlapping of labels and to improve readability.

Map was produced as below. If needed, one may download the SpatialPolygonsDataframe object 'mymap' here.

trellis.par.set() is not solving my problem. Am I using it incorrectly?

    library(sp)
    library(latticeExtra)

    # Create list object for sp.layout (Got these functions here on stackoverflow, thank you owner)
    sp.label <- function(x, label) {list("sp.text", coordinates(x), label)}
    NUMB.sp.label <- function(x) {sp.label(x, as.vector(x@data$NUMB))}
    make.NUMB.sp.label <- function(x) {do.call("list", NUMB.sp.label(x))}


    # Spplot
    tps <- list(fontsize=list(text=5), fontcolor=list(text="green"))
    trellis.par.set(tps)

    spplot(mymap, "indic", 
                    col.regions=c("#D3D3D3","#A9A9A9"),
                    sp.layout = make.NUMB.sp.label(mymap), 
                    cex = 0.5,
                    bg = "white", col="light grey", border="light grey")

Rosetterosewall

The link to the 'mymap' object is broken, so there's no way to reproduce the output. It would be nice if you could do something about it. – Uganda

Answer 1

Found the solution: Needed to add cex, col arguments in the list:

 list("sp.text", coordinates(x), label, cex=0.5, col="green")

Rosetterosewall