使用is.來測試數(shù)據(jù)類型。返回TRUE或FALSE Use
as.來轉(zhuǎn)換。
is.numeric(), is.character(), is.vector(), is.matrix(), is.data.frame()
as.numeric(), as.character(), as.vector(), as.matrix(), as.data.frame)
is.matrix(zuowei)
[1] TRUE
y <- as.vector(zuowei)
is.vector(y)
[1] TRUE
| ， | to one long vector | to matrix | to data frame |
|---|---|---|---|
| from vector | c(x,y) | cbind(x,y) | rbind(x,y) data.frame(x,y) |
| from matrix | as.vector(mymatrix) | as.data.frame(mymatrix) | |
| from data frame | as.matrix(myframe) |
