Norman Matloff,著名计算机科学家兼统计学家,美国加州大学戴维斯分校计算机科学系教授,曾是该校统计专业的创建者之一,并担任过统计学教授。对并行编程、网络流量、数据挖掘、磁盘系统性能等方面的技术都有深入的研究。乐于分享,撰写了多部广受欢迎的关于软件开发的在线教程,多次为《纽约时报》《华盛顿邮报》《福布斯杂志》以及《洛杉矶时报》撰写文章,同时他还是《The Art of Debugging》的作者之一。
"The reason we cannot suddenly spring an expression like y[2] on R stems from R’s functional language nature. The reading and writing of individual vector elements are actually handled by functions. If R doesn’t already know that y is a vector, these functions have nothing on which to act."
"Here str stands for structure. This function shows the internal structure of any R object, not just list."
"Negative subscripts mean that we want to exclude the given elements in our output."
"But this book is for those who wish to develop software in R 运行R 1,R operates in two modes: interactive and batch. console中运行R文件:source("z.R") 2,R中的注释:#开头的行 3, batch: R CMD BATCH z.R 要将R的bin目录加入环境变量Path R的语句:赋值、循环 1,x <- c(1,2,4) There are no fixed types associated with variables. x之后可以被赋予别的类型的值。 c "