# An R function to clear the screen on RGui:
cls <- function() {
if (.Platform$GUI[1] != "Rgui")
return(invisible(FALSE))
if (!require(rcom, quietly = TRUE)) # Not shown any way!
stop("Package rcom is required for 'cls()'")
wsh <- comCreateObject("Wscript.Shell")
if (is.null(wsh)) {
return(invisible(FALSE))
} else {
comInvoke(wsh, "SendKeys", "\014")
return(invisible(TRUE))
}
}
#cls() # test
# If you want to make sure that it worked (well, not 100% sure, but...)
res <- cls()
if (res) cat("Console should be cleared now!\n")
使用data.frame函数就可以初始化一个Data Frame。比如我们要初始化一个student的Data Frame其中包含ID和Name还有Gender以及Birthdate，那么代码为：student<-data.frame(ID=c(11,12,13),Name=c("Devin","Edward","Wenli"),Gender=c("M","M","F"),Birthdate=c("1984-12-29","1983-5-6","1986-8-8”))
另外也可以使用read.table() read.csv()读取一个文本文件，返回的也是一个Data Frame对象。读取数据库也是返回Data Frame对象。
