Extends formula's with predictor matrix settings
extend.formulas(formulas, data, blocks, predictorMatrix = NULL,
auxiliary = TRUE, include.intercept = FALSE, ...)
A named list of formula's, or expressions that
can be converted into formula's by as.formula
. List elements
correspond to blocks. The block to which the list element applies is
identified by its name, so list names must correspond to block names.
The formulas
argument is an alternative to the
predictorMatrix
argument that allows for more flexibility in
specifying imputation models, e.g., for specifying interaction terms.
A data frame or a matrix containing the incomplete data. Missing
values are coded as NA
.
List of vectors with variable names per block. List elements
may be named to identify blocks. Variables within a block are
imputed by a multivariate imputation method
(see method
argument). By default each variable is placed
into its own block, which is effectively
fully conditional specification (FCS) by univariate models
(variable-by-variable imputation). Only variables whose names appear in
blocks
are imputed. The relevant columns in the where
matrix are set to FALSE
of variables that are not block members.
A variable may appear in multiple blocks. In that case, it is
effectively re-imputed each time that it is visited.
A numeric matrix of length(blocks)
rows
and ncol(data)
columns, containing 0/1 data specifying
the set of predictors to be used for each target column.
Each row corresponds to a variable block, i.e., a set of variables
to be imputed. A value of 1
means that the column
variable is used as a predictor for the target block (in the rows).
By default, the predictorMatrix
is a square matrix of ncol(data)
rows and columns with all 1's, except for the diagonal.
Note: For two-level imputation models (which have "2l"
in their names)
other codes (e.g, 2
or -2
) are also allowed.
A logical that indicates whether the variables
listed in predictors
should be added to the formula as main
effects. The default is TRUE
.
A logical that indicated whether the intercept should be included in the result.
Named arguments that are passed down to the univariate imputation functions.
A list of formula's