| data.matrix {base} | R Documentation |
Return the matrix obtained by converting all the variables in a data frame to numeric mode and then binding them together as the columns of a matrix. Factors and ordered factors are replaced by their internal codes.
data.matrix(frame)
frame |
a data frame whose components are logical vectors, factors or numeric vectors. |
Supplying a data frame with columns which are not numeric, factor or logical is an error. A warning is given if any non-factor column has a class, as then information can be lost.
If frame is a data frame, a numeric matrix of the same
dimensions as frame, with dimnames taken from the row.names and
names.
Otherwise, the result of as.matrix.
Chambers, J. M. (1992) Data for models. Chapter 3 of Statistical Models in S eds J. M. Chambers and T. J. Hastie, Wadsworth & Brooks/Cole.
as.matrix,
data.frame,
matrix.
DF <- data.frame(a=1:3, b=letters[10:12],
c=seq(as.Date("2004-01-01"), by = "week", len = 3),
stringsAsFactors = TRUE)
data.matrix(DF[1:2])
data.matrix(DF) # gives a warning and quotes dates as #days since 1970.