[R] Question about barplot: gridlines & value labels

[Jim Lemon]

Dimitri Liakhovitski wrote:
> Hello!
> I promise I looked into help files before asking. Still cannot figure
> it out. I think it's because I am totally confused what packages use
> lettice, which use trellis, etc.
> Sections 1 and 2 below produce the data and the data to plot. My
> question is about barplot in Section 3. I am trying to:
> 1. add only horizontal gridlines and manipulate the type and color of
> that line. tck = 1 is not flexible enough to do it.
> 2. make the legend come on top of gridlines and not under them
> 3. add plotted Y values above the bars
>
> Thank you very much for any pointers!
> Dimitri
>
> ### Section 1: generates my data set "data":
>
> N<-100
> myset1<-c(1,2,3,4,5)
> probs1<-c(.05,.10,.15,.40,.30)
>
> group<-unlist(lapply(1:4,function(x){
> 	out<-rep(x,25)
> 	return(out)
> }))
> set.seed(1)
> a<-sample(myset1, N, replace = TRUE,probs1)
> a[which(rbinom(100,2,.01)==1)]<-NA
> set.seed(12)
> b<-sample(myset1, N, replace = TRUE,probs1)
> b[which(rbinom(100,2,.01)==1)]<-NA
> set.seed(123)
> data<-data.frame(group,a=a,b=b)
> data["group"]<-lapply(data["group"],function(x) {
> 	x[x %in% 1]<-"Group 1"
> 	x[x %in% 2]<-"Group 2"
> 	x[x %in% 3]<-"Group 3"
> 	x[x %in% 4]<-"Group 4"
> 	return(x)
> })
> data$group<-as.factor(data$group)
> lapply(data,table,exclude=NULL)
>
> ### Section 2. Creating data to plot:
> table.a<-with(data,table(group,a))
> table.a.percents<-apply(table.a,2,function(x){
> 	out<-round(x*100/sum(x),1)
> 	return(out)
> })
>
> ### Section 3. Creating a plot:
> barplot(table.a.percents,xlab = "Values", ylab =
> "Percentages",ylim=c(0,100),axis.lty=1,legend=T,beside=T,tck = 1)
>
>   
Hi Dimitri,
I think you will have to display the legend separately:

legend(20,90,rownames(table.a.percents),
 fill=c("gray30","gray50","gray70","gray90"),bg="white")


I tried passing the bg="white" argument in barplot, but it had no 
effect. Probably gobbled by another function before it got to legend.

Jim