函数名<-function(parameters){
statemens
return(expression)}
printLine <- function () { print("--------------------------------------------"); } #函数的调用 printLine(); #错误：无参函数，有参调用 printLine("parameter"); printNLines <- function (n) { for(i in 1:n) { print("--------------------------------------------"); } } #错误：有参函数，无参调用 printNLines() printNLines(3) printNLines <- function (n=1) { for(i in 1:n) { print("--------------------------------------------"); } } #正确：有参函数，因为有默认值，可以无参调用 printNLines() #也可以有参数调用 printNLines(3) printInfo <- function (name, age) { print(paste("name is: ", name, ", age is: ", age, sep="")) } printInfo("KEN", 18) printInfo(age=18, name="KEN") printInfo <- function (name, age, ...) { print(paste("name is: ", name, ", age is: ", age, sep="")); otherParames = list(...); for(key in names(otherParames)) { print(paste(key, " is: ", otherParames[key], sep="")); } } printInfo("KEN", 18, height="178CM", weight="75KG", sex="男"); data <- read.csv("data.csv", sep=",", fileEncoding='utf8'); summary(data[,3]) #summary加强版 summaryEx <- function(column) { s <- summary(column) #方差 s[['var']] <- var(column); #标准差 s[['sd']] <- sd(column); #s #直接写个s也可以替代下面的语句 return (s); } summaryEx(data[, 3])