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What is R?

陆勤

R is a high-level language and environment for data analysis and visualization. It provides an environment in which you can perform statistical analysis and produce high-quality graphics. It is actually a complete programming language derived from the statistical programming language S.

【陆勤看点】R是一种高级语言，也是一种软件环境和平台。R源自S语言，吸收了S语言的优势。R适合做统计分析或数据分析，产生高质量的图片。但是，其功能不局限于这些。

It has been developed and is maintained by a core of statistical programmers, with the support of a large community of users. It is most widely used for statistical computing and graphics, but is a fully functional programming language well suited for scientific programming, data management,and data visualization in general.

【陆勤看点】感谢Ross和Robot开创了R，感谢核心小组成员维护和壮大了R，感谢无数分享R包的朋友们，让R能够做更多有趣的事情，有着更广的应用。R有着广泛地用途，很多数据分析师、数据科学家都用R做事情，比方说数据预处理、数据分析、数据可视化，甚至数据报告等。R提供和实现了很多数据分析方法。

The interaction with the R system is mainly command-driven, with the user typing in text and asking R to execute the specific command. As soon as you start R, a session will be opened on which the commands may be introduced and the expression executed. Complex procedures can be implemented in the scripts, which are executed as soon as they are loaded into the system or, more efficiently, as functions, which can be loaded in the system and used when needed.

【陆勤看点】R是一种命令行交互方式的程序设计语言。简单的事情，通过对会话下达命令，回车键后即执行命令；复杂的事情，通过编写和执行脚本，来处理和完成。

Getting help

R提供了丰富的帮助文档，这是一种很好的学习R的方法。

help.start() help(mean)

在R的IDE-RStdio工具里面，选择Help，两份文档如下

《An Introduction to R》
《Writing R Extensions》

R packages

An R package is a collection of source code and other additional files that, when installed in R, allow the user to load them in the workspace via a call to the library() function.

【陆勤看点】R是一个源码和其它文件的容器，安装它，加载它，就可以使用它，很方便，很强大。小编一直专注于机器学习和数据挖掘，会经常应用R来实践哦。