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R2-36第二阶段第三次作业
installed.packages("killDbConnections")
library(RMySQL)
killDbConnections<-function(){
all_cons<-dbListConnections(MySQL())
print(all_cons)
for(con in all_cons)
+ dbDisconnect(con)
print(paste(length(all_cons),"connections killed."))
}
killDbConnections()
con<-dbConnect(MySQL(),host="localhost",dbname="rdb",user="root",password="")
dbSendQuery(con,'SET NAMES utf8')
rs <- dbSendQuery(con,"SELECT * FROM article WHERE isdone=1")
words=data.frame(word=c(),freq=c())
while(!dbHasCompleted(rs)){
chunk<-dbFetch(rs,10)
count=nrow(chunk)
cnt=1
while(cnt<=count){
str=gsub("[[:punct:]]","", tolower(chunk[cnt,5]))
temp=as.vector(unlist(strsplit(str,split=" ")))
temp_len=length(temp)
cnt2=1
while(cnt2<=temp_len){
if(temp[cnt2] %in% words$word){
words[words$word==temp[cnt2],]$freq=words[words$word==temp[cnt2],]$freq+1
}
else{
words=rbind(words,data.frame(word=c(temp[cnt2]),freq=c(1)))
}
cnt2=cnt2+1
}
cnt=cnt+1
}
}
head(words)
第二题 install.packages("wordcloud2")始终安装不了
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