RHadoop实现wordcount

参考文献:《Big Data Analytics With R And Hadoop》

wordcount等于hello word

so,begin

wordcount = function(input,output = NULL,pattern = " ")
{
wc.map = function(., lines)
{
keyval(unlist(strsplit(x = lines,split = pattern)),1)
}
wc.reduce = function(word, counts )
{
keyval(word, sum(counts))
}
mapreduce(input = input ,output = output,input.format = "text",map = wc.map,reduce = wc.reduce,combine = T)
}

hdfs.put('/home/hadoop/桌面/word','/RHadoop/1/')

wordcount('/RHadoop/1/')

需要做的：修改路径，在对应路径创建一个名为word的文件。。然后把英文放进去。亲测。伪分布式600M十四分钟。10台机器完全分布式1.4G三分四十秒。不过当时环境不稳定现在应该更快。