tcctomat(ccov, names=NULL, oldccov=NULL, dataframe=TRUE)
ccov
| A vector or matrix containing time-constant baseline covariates with one row per individual, a model formula using vectors of the same size, or an object of class, tccov. |
names
| The names of the covariates (if the matrix does not have column names). |
oldccov
| An object of class, tccov, to which ccov is to be added. |
dataframe
| If TRUE and factor variables are present, the covariates are stored as a dataframe; if FALSE, they are expanded to indicator variables. If no factor variables are present, covariates are always stored as a matrix. |
tcctomat
creates an object of class, tccov, from a vector or
matrix containing time-constant baseline covariates or a model formula,
or combines two such objects.
Such objects can be printed. Methods are available for extracting the
covariates, their names, and the formula: covariates
,
names
, and formula
. The method, link{transform}
,
can transform variables in place or by adding new variables to the
object.
To obtain the indexing to expand time-constant covariates to the size
of a repeated measurements response, use covind
.
read.list
, restovec
, rmna
,
transform
, tvctomat
.x1 <- gl(4,1) print(tcc1 <- tcctomat(~x1)) covariates(tcc1) covariates(tcc1, name="x12") tcctomat(x1) tcctomat(x1, dataframe=T) x2 <- c(0,0,1,1) print(tcc2 <- tcctomat(~x2)) covariates(tcc2) print(tcc3 <- tcctomat(~x1+x2)) covariates(tcc3) covariates(tcc3, names=c("x12","x2")) formula(tcc3) names(tcc3) print(tcc4 <- tcctomat(data.frame(x1,x2))) covariates(tcc4) print(tcc5 <- tcctomat(data.frame(x1,x2), dataframe=T)) covariates(tcc5)