R2-20 第二阶段第四次作业

科研狗聪 2018-05-05 22:14:46 阅读: 3110

library("httr")

yearData=c()
countData=c()
url = "https://eutils.ncbi.nlm.nih.gov/entrez/eutils/esearch.fcgi"

for(i in 1:10){
  year=2007+i
  term = paste('(Small nucleolar RNA[TI]) AND ',year,'[DP]',sep = "")
  r <- POST(url, 
            body = list(
              db='pubmed',
              term=term,
              retmode='json',
              retstart=0,
              retmax=10,
              rettype='uilist'
            )
  )
  
  stop_for_status(r) #清除http状态字符串
  data=content(r, "parsed", "application/json")  
  esearchresult=data$esearchresult
  count = esearchresult$count
  yearData=c(yearData,year)
  countData=c(countData,count)
}
data=data.frame(year=yearData,count=countData)
print(data)

library(ggplot2)
ggplot(data,aes(x=factor(year),y=count))+
  geom_bar(aes(fill=year), stat="identity",width = 0.8)+
  geom_text(label=data$count,vjust=-0.5)+
  xlab("year")+ylab("count")+ 
  theme_bw()+
  theme(legend.position="none")+
  ggtitle("R2-20")

好奇怪，没办法上传图片或者附件

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