AC/DC tells the little-known story of how Thomas Edison wrongly bet in the fierce war between supporters of alternating current and direct current. The savagery of this electrical battle can hardly be imagined today. The showdown between AC and DC began as a rather straightforward conflict between technical standards, a battle of competing methods to deliver essentially the sam...(展开全部)

Great play, that introduced the word "robot" into English, looks to a future in which all workers are automatons. They revolt when they acquire souls (i.e., when they gain the ability to hate) and the resulting catastrophe make for a powerful and deeply moving theatrical experience. Paul Selver translation.

R.U.R.--written in 1920, premiered in Prague in 1921, and first performed in New York in 1922--garnered worldwide acclaim for its author and popularized the word robot. Mass-produced as efficient laborers to serve man, Capek's Robots are an android product--they remember everything but think of nothing new. But the Utopian life they provide ultimately lacks meaning, and the hum...(展开全部)

本书分为上下两部分，旨在指导你如何使用R，并提供练习的机会。上半部分主要介绍R的技术细节和使用技巧。每章都简要介绍了一组不同的数据类型（例如第4章介绍向量、矩阵和数组）或概念（例如第8章介绍分支和循环）。下半部分更侧重实践，展示了从输入数据到发布结果这一标准的数据分析流程。 即使你没有任何编程基础，也能顺利阅读本书。 编写简单的R程序，知道R语言能做什么 使用向量、数组、列表、数据框和字符串等数据类型 掌握条件语句以及分支和循环控制语句 应用R的扩展包，将你自己的工作成果打包发给其他人 清理从各种来源导入的数据 通过可视化和汇总统计理解数据 使用统计模型传递关于数据的定量判断并进行预测 了解编写数据分析代码时出现错误的应对措施

Great play, that introduced the word "robot" into English, looks to a future in which all workers are automatons. They revolt when they acquire souls (i.e., when they gain the ability to hate) and the resulting catastrophe make for a powerful and deeply moving theatrical experience. Paul Selver translation.

R.U.R.--written in 1920, premiered in Prague in 1921, and first performed in New York in 1922--garnered worldwide acclaim for its author and popularized the word robot. Mass-produced as efficient laborers to serve man, Capek's Robots are an android product--they remember everything but think of nothing new. But the Utopian life they provide ultimately lacks meaning, and the hum...(展开全部)

简介：我是R天使，雷狮，欢迎各位前来参加凹凸大赛