test for data type

is.numeric(), is.character(), is.vector(), is.matrix(), is.data.frame()

convert it
as.numeric(), as.character(), as.vector(), as.matrix(), as.data.frame)

vector/matrix/data.frame

	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)