數(shù)據(jù)框也是一張二維表格，行和列在統(tǒng)計(jì)上分別稱為觀測(cè)和變量，計(jì)算機(jī)上分別稱為記錄和域。變量名的對(duì)應(yīng)稱謂是域名，變量值對(duì)應(yīng)域值

創(chuàng)建數(shù)據(jù)框

data.frame(域名1=向量名1,域名2=向量名2,….)

names(數(shù)據(jù)框名)

訪問數(shù)據(jù)框

數(shù)據(jù)框名$域名、數(shù)據(jù)框名[[“域名”]]、數(shù)據(jù)框名[[域編號(hào)]]

attach函數(shù)和detach函數(shù)、with函數(shù)

> male<-c(124,88,200)

> female<-c(108,56,221)

> degree<-c("low","middle","high")

> myopia<-data.frame(degree,female,male)

> myopia

degree female male

1 low 108 124

2 middle 56 88

3 high 221 200

訪問

> myopia$degree

[1] low middle high

Levels: high low middle

> myopia[["degree"]]

[1] low middle high

Levels: high low middle

> myopia[[1]]

[1] low middle high

Levels: high low middle