5.1 Introdution The main focus of this chapter is to discuss the order inversion (OI) pattern, which can be used in solving some problems using MapReduce framework. The OI pattern enables us to control the order of values received at a reducer (some
by 写长城的诗 • October 30, 2011 • Comments Off This post was kindly contributed by 数据科学与R语言 - go there to comment and to read the full post. 一.数据导入 对初学者来讲,面对一片空白的命令行窗口,第一道真正的难关也许就是数据的导入.数据导入有很多途径,例如从网页抓取.公共数据源获得.文本文件导入.为了快速入门,建议初学者采取R语言协同Excel电子表格的方法.也就