Creates a formulas argument

This helper function creates a valid formulas object. The formulas object is an argument to the mice function. It is a list of formula's that specifies the target variables and the predictors by means of the standard ~ operator.

Usage

make.formulas(data, blocks = make.blocks(data), predictorMatrix = NULL)

Arguments

data

A data.frame with the source data

blocks

An optional specification for blocks of variables in the rows. The default assigns each variable in its own block.

predictorMatrix

A predictorMatrix specified by the user.

Value

A list of formula's.

See also

make.blocks, make.predictorMatrix

Examples

f1 <- make.formulas(nhanes)
f1
#> $age
#> age ~ bmi + hyp + chl
#> <environment: 0x564348bdefb8>
#> 
#> $bmi
#> bmi ~ age + hyp + chl
#> <environment: 0x564348bdefb8>
#> 
#> $hyp
#> hyp ~ age + bmi + chl
#> <environment: 0x564348bdefb8>
#> 
#> $chl
#> chl ~ age + bmi + hyp
#> <environment: 0x564348bdefb8>
#> 
f2 <- make.formulas(nhanes, blocks = make.blocks(nhanes, "collect"))
f2
#> $collect
#> age + bmi + hyp + chl ~ `0`
#> <environment: 0x564348a9ab08>
#> 

# for editing, it may be easier to work with the character vector
c1 <- as.character(f1)
c1
#> [1] "age ~ bmi + hyp + chl" "bmi ~ age + hyp + chl" "hyp ~ age + bmi + chl"
#> [4] "chl ~ age + bmi + hyp"

# fold it back into a formula list
f3 <- name.formulas(lapply(c1, as.formula))
f3
#> $age
#> age ~ bmi + hyp + chl
#> <environment: 0x56434848b2d0>
#> 
#> $bmi
#> bmi ~ age + hyp + chl
#> <environment: 0x56434848b2d0>
#> 
#> $hyp
#> hyp ~ age + bmi + chl
#> <environment: 0x56434848b2d0>
#> 
#> $chl
#> chl ~ age + bmi + hyp
#> <environment: 0x56434848b2d0>
#>