输入数据为一个向量，数值范围为0-100百分数：

现在我需要按照指定的间隔范围统计，数值出现的频率得到结果绘制饼图：

统计数据，以及ggplot2绘图饼图代码如下：

library(reshape2)
local({r <- getOption("repos")  ;r["CRAN"] <- "http://mirrors.tuna.tsinghua.edu.cn/CRAN/" ;options(repos=r)}) 
library(ggplot2)
library(cowplot)
library(RColorBrewer)



pairjoinC <- function(x,y){ 
  ran1=paste(paste(head(x,-1),"%",sep=""), paste(tail(x,-1),"%",sep=""), sep="-")
  ran1[length(ran1)]=">40%"
  ran1=paste(ran1," (",y,")",sep="")
  
  ran1
}



# use the base hist() function to calculate BINs ，超过40%的统计到一起；

data[data>40]=41
MassStatC <- with(hist(data, breaks=seq(0, 45, by = 5), plot=FALSE), data.frame(N=counts, Mass=pairjoinC(breaks,counts), PCT=counts/sum(counts)))
MassStatC$Mass=factor(MassStatC$Mass, levels=rev(MassStatC$Mass), order=T)
pe = ggplot(MassStatC, aes(x="", y= N, fill= Mass))+
  geom_bar(stat="identity",width=1)+
  coord_polar(theta="y")+
  labs(x="", y="",title="Distribution of Protein's Sequence Coverages")+

  theme(axis.ticks = element_blank(), axis.text.x = element_blank())+
  scale_fill_brewer(palette="Paired",breaks = MassStatC$Mass, labels = as.character(MassStatC$Mass),direction=-1)+
  geom_text(aes(x = 1.7, y = cumsum(MassStatC$N)-MassStatC$N/2 , label =paste( as.character(round(MassStatC$PCT*100,2)),"%",sep="")), show.legend = FALSE, color="black")+
  theme(plot.title = element_text(hjust = 0.5), 
        legend.title = element_blank(),
        panel.background = element_rect(fill = "transparent",colour = NA), 
        panel.grid.minor = element_blank(), 
        panel.grid.major = element_blank(),
        axis.line= element_blank(),
        plot.background = element_rect(fill = "transparent",colour = NA))
pe

更多R语言绘图，可观看《R语言绘图视频课程》