R help - Jan 2013 - add categorical labels in plot

Hello

I want to draw a plot using the code below.

Further, I want to add labels (White, Yellow, Red) to x-axis.
Please kindly advise how to add the categorical labels, by modifying the
code.
Thank you.

Elaine

Code

dataN <-read.csv("H:/skin_color.csv",header=T, row.names=1)

    dim(dataN)

    dataN[1,]

    str(dataN)



    obs.group<-dataN$skin_color

    levels(dataN$skin_color) <- skin.code



    skin.code <- c("White", "Yellow", "Red")



  # graph

    par(mai=c(1.03,1.03,0.4,0.4))

    par(new=T)



    plot(dataN$skin_color, dataN$body_length,

    xlab="Skin Color",

    ylab="Body Lenght",

    xaxt="n",

    type="p",

    pch=1,lwd=2.0,

    cex.lab=1.4, cex.axis=1.2,

    font.axis=2,

    cex=1.5,

    las=1,

    bty="l",

    col=c("gray38","orange","red2")[obs.group])

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On 01/12/2013 12:01 PM, Elaine Kuo wrote:
> Hello
>
> I want to draw a plot using the code below.
>
> Further, I want to add labels (White, Yellow, Red) to x-axis.
> Please kindly advise how to add the categorical labels, by modifying the
> code.
>...
Hi Elaine,
Bit hard to tell exactly what you want, but try this:

ek.data<-data.frame(
 
skin_color=sample(c("white","yellow","red"),100,TRUE),
  body_length=runif(100,80,120))
skin.colors<-c("white","yellow","red")
plot(as.numeric(ek.data$skin_color),ek.data$body_length,
  bg=skin.colors[as.numeric(ek.data$skin_color)],pch=21,
  xlim=c(0.5,3.5),xaxt="n")
axis(1,at=1:3,labels=skin.colors)

Jim