# [R] Barchart in lattice - wrong order of groups, data labels on top of each other, and a legend question

Dimitri Liakhovitski ld7631 at gmail.com
Mon May 18 20:47:42 CEST 2009

```Hello!
I have a question about my lattice barchart that I am trying to build
in Section 3 below. I can't figure out a couple of things:
1. When I look at the dataframe "test" that I am trying to plot, it
looks right to me (the group "Total" is always the first out of 5).
However, in the chart it is the last. Why?
2. How can I make sure the value labels (on y) are not sitting on top
of each other but on top of the respective bar?
3. Is there any way to make the legend group items horizontally as
opposed to now (vertically - taking up too much space)

Thanks a lot!
Dimitri

### Section 1: generates my data set "data" - just run: #####

N<-100
myset1<-c(1,2,3,4,5)
probs1<-c(.05,.10,.15,.40,.30)
myset2<-c(0,1)
probs2<-c(.65,.30)
myset3<-c(1,2,3,4,5,6,7)
probs3<-c(.02,.03,.10,.15,.20,.30,.20)

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)
c<-sample(myset2, N, replace = TRUE,probs2)
set.seed(1234)
d<-sample(myset2, N, replace = TRUE,probs2)
set.seed(12345)
e<-sample(myset3, N, replace = TRUE,probs3)
e[which(rbinom(100,2,.01)==1)]<-NA
set.seed(123456)
f<-sample(myset3, N, replace = TRUE,probs3)
f[which(rbinom(100,2,.01)==1)]<-NA
data<-data.frame(group,a=a,b=b,c=c,d=d,e=e,f=f)
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)

tables<-lapply(data,function(x){
out<-table(x)
out<-prop.table(out)
out<-round(out,3)*100
return(out)
})
str(tables[2])

##### Section 2: Generating a list of tables with percentages to be
plotted in barcharts - just run: #####

listoftables<-list()
for(i in 1:(length(data)-1)) {
listoftables[[i]]<-data.frame()
}
for(i in 1:length(listoftables)) {
total<-table(data[[i+1]])
groups<-table(data[[1]],data[[i+1]])
total.percents<-as.data.frame(t(as.vector(round(total*100/sum(total),1))))
groups.percents<-as.data.frame(t(apply(groups,1,function(x){
out<-round(x*100/sum(x),1)
return(out)
})))
names(total.percents)<-names(groups.percents)
final.table<-rbind(total.percents,groups.percents)
row.names(final.table)[1]<-"Total"
final.table<-as.matrix(final.table)
listoftables[[i]]<-final.table
}
names(listoftables)<-names(data)[2:(length(listoftables)+1)]

### Section 3 - building the graph for the very first table of the
"listoftables" ###
library(lattice)
i<-1
test <- data.frame(Group = rep(row.names(listoftables[[i]]),5), a =
rep(1:5,each=5),Percentage = as.vector(listoftables[[i]]))
par.settings=trellis.par.set(reference.line = list(col = "gray", lty ="dotted"))
barchart(Percentage~a, test, groups = Group, horizontal = F,
auto.key = list(points = FALSE, rectangles = TRUE, space =
"bottom"),ylim = c(0,50),
panel = function(y,x,...) {
panel.grid(h = -1, v = -1)
panel.barchart(x, y, ...)
ltext(x, y, labels=round(y,0),cex=.7,col="black",font=2,pos=3)
})

--
Dimitri Liakhovitski
MarketTools, Inc.
Dimitri.Liakhovitski at markettools.com

```