Name formula list elements

This helper function names any unnamed elements in the formula list. This is a convenience function.

Usage

name.formulas(formulas, prefix = "F")

Arguments

formulas

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.

prefix

A character vector of length 1 with the prefix to be using for naming any unnamed blocks with two or more variables.

Value

Named list of formulas

Details

This function will name any unnamed list elements specified in the optional argument formula. Unnamed formula's consisting with just one response variable will be named after this variable. Unnamed formula's containing more than one variable will be named by the prefix argument, padded by an integer sequence stating at 1.

See also

mice

Examples

# fully conditionally specified main effects model
form1 <- list(
  bmi ~ age + chl + hyp,
  hyp ~ age + bmi + chl,
  chl ~ age + bmi + hyp
)
form1 <- name.formulas(form1)
imp1 <- mice(nhanes, formulas = form1, print = FALSE, m = 1, seed = 12199)

# same model using dot notation
form2 <- list(bmi ~ ., hyp ~ ., chl ~ .)
form2 <- name.formulas(form2)
imp2 <- mice(nhanes, formulas = form2, print = FALSE, m = 1, seed = 12199)
identical(complete(imp1), complete(imp2))
#> [1] FALSE

# same model using repeated multivariate imputation
form3 <- name.blocks(list(all = bmi + hyp + chl ~ .))
imp3 <- mice(nhanes, formulas = form3, print = FALSE, m = 1, seed = 12199)
cmp3 <- complete(imp3)
identical(complete(imp1), complete(imp3))
#> [1] FALSE

# same model using predictorMatrix
imp4 <- mice(nhanes, print = FALSE, m = 1, seed = 12199, auxiliary = TRUE)
identical(complete(imp1), complete(imp4))
#> [1] FALSE

# different model: multivariate imputation for chl and bmi
form5 <- list(chl + bmi ~ ., hyp ~ bmi + age)
form5 <- name.formulas(form5)
imp5 <- mice(nhanes, formulas = form5, print = FALSE, m = 1, seed = 71712)