[R] Text on a boxplot graph

[Uwe Ligges]

François Le Lay wrote:
> Hi all,
> 
> Could anybody help me figure out how to write text on a boxplot. I have to 
> plot 9 boxplots side by side on a single graph. On the x-axis I write numeric 
> values with the 'names' argument but I'd like to add one label (character 
> value) in the middle of each box. I know how to use the text() function for 
> regular y~x plots but in this particular case, I'm kinda lost...
> Here is my code:
> 
> # creating labels for x-axis labelling 
> lb <- c()
> for( n in names(o) )
>   lb <- c(lb, paste("\n",n,"\n",o[[n]], sep=""))
> 
> boxplot(x[,-c(10,11)],
>         varwidth=TRUE,         			 
> col=c("#FF0000","#EE0000","#DD0000","#00FF00","#0000FF","#0000DD","#0000BB","#000099"),	
>         col.lab="dark red",
>         col.axis="blue",
>         main="Boxplots for Polling results, 1868 clusters, 9604 simulated 
> requests",
>         names=lb,
>         xlab="RED BOXPLOTS: precision dependent - GREEN BOXPLOT: null radius - 
> BLUE BOXPLOTS: percent of exact radius",
>  	       ylab="P(ID) values")
> 
> 
> Thanks for your help,
> Fanch
>  


As an example how to write text in the boxes directly below the median 
line, I'd suggest to use:

temp <- boxplot(.... your boxplot arguments ....)
text(seq(along = temp$n), temp$stats[3, ],
     labels = c("text.box.1", "text.box.2"), pos = 1)

Uwe Ligges