R中的Barplot：更改顺序和控制标签

Question

I have small data and I want to get bar-plot. I managed to graph the data. However, I have two questions.

1) I want to make the bars to be plotted in order according to the X-axis, not according the values. The x-axis is a range like : <40,100-500,500-1000, .....

some values like 40-100 is greater than 500-1000, it is plotted at the end. I want the bars to be based on the values of X-axis.

2) How do I control the position of the label value on each bar.

Here is my data from dput :

structure(list(range = structure(c(1L, 6L, 2L, 7L, 3L, 4L, 5L
), .Label = c("<40", "100-500", "1000-1468", "1469-1479", "1480-1500", 
"40-100", "500-1000"), class = "factor"), values = c(100L, 10000L, 
1000L, 505L, 2000L, 50L, 5000L)), .Names = c("range", "values"
), class = "data.frame", row.names = c(NA, -7L))

here is my code:

DF$X<-NULL
colnames(DF)<-c("Size","occurances")
gr2<- ggplot(DF, aes(x =Size , y= occurances))+ 
      geom_bar(aes(fill=Size),stat="identity") +
      geom_text(aes(label = paste(sprintf("%0.0f", occurances)),
            y = occurances+0.25, x=Size),
           size = 5, face="bold",position = position_dodge(width=0.9)) +
      theme(axis.text.x=element_text(size=12,colour="gray19",face="bold"),
            axis.text.y=element_text(colour="gray19",size=12,face="bold"))+
      theme(axis.ticks.x = element_line(size = 2))+
      scale_x_discrete(breaks=c("<40","40-100","100-500","500-1000","1000-1468","1469-  1479","1480-1500"),expand=c(0,0) )+
      scale_y_continuous(expand=c(0.008,0.5))+
      guides(fill=FALSE)
      print(gr2)

Any suggestions !!

Answer 1

Try:

DF$Size <- reorder(DF$Size, seq_along(DF$Size))
gr2<- ggplot(DF, aes(x =Size , y= occurances))+ 
  geom_bar(aes(fill=Size),stat="identity") +
  geom_text(aes(label = paste(sprintf("%0.0f", occurances)),
                y = occurances+0.25, x=Size),
            size = 5, face="bold", vjust=-.8) +
  theme(axis.text.x=element_text(size=12,colour="gray19",face="bold"),
        axis.text.y=element_text(colour="gray19",size=12,face="bold"))+
  theme(axis.ticks.x = element_line(size = 2))+
  scale_y_continuous(expand=c(0.1,0))+
  guides(fill=FALSE)
print(gr2)

The key thing is to re-order your factor levels so that they actually are in increasing order (here I took advantage of the fact that your DF was already sorted in that order). Then you can use vjust in geom_text to get the alignment right. Note I also messed with expand with the y scale. Also, got rid of your scale_x_discrete call as I think you were trying to use that to change the ordering, but that isn't necessary if you get the factor levels right.

As an aside, how did you generate the buckets? You should consider using cut , as that should set up your levels in the correct order.