Section 9 Dataframe

9.1 Function

Example vector: x <- c(1:10); y <- rep(c('M','F'), each=5); z <- rep(c(T,F), length=10)

Function	Explanation	Example
data.frame	Create a data.frame	DF <- data.frame(Age=x, Sex=y, Vac=z)
as.data.frame	Coerce into a data.frame	as.data.frame(DF)
is.data.frame	Check if its argument is a data.frame	is.data.frame(DF)
dim	Get the dimension of a data.frame	dim(DF)
dimnames	A dimnames attribute for a data.frame	dimnames(DF)
names, colnames	Column names of a data.frame	names(DF)
row.names, rownames	Row names of a data.frame	row.names(DF)
attributes	Attributes of a data.frame	attributes(DF)

9.2 Example

?data.frame

x <- c(1:10)
y <- rep(c('M','F'), each=5)
z <- rep(c(T,F), length=10)

DF <- data.frame(Age=x, Sex=y, Vac=z)
DF

is.data.frame(DF)
dim(DF)
dimnames(DF)

names(DF)
colnames(DF)
rownames(DF)

attributes(DF)

str(DF)

Note: Data frames are usually created by reading in a dataset using the functions read.table() or read.csv(). We will cover this later.