simplify_formula function

Simplify formula with inline functions

lifecycle::badge("experimental")

Extracts all variables from a formula object and creates a new formula with all predictor variables added together without the inline functions.

E.g.:

y ~ x*z + log(a) + (1|b)

becomes

y ~ x + z + a + b.

This is useful when passing a formula to recipes::recipe()

for preprocessing a dataset, as used in the preprocess_functions().

simplify_formula(formula, data = NULL, string_out = FALSE)

Arguments

• formula: Formula object.

  If a string is passed, it will be converted with as.formula().

  When a side only contains a NULL, it is kept. Otherwise NULLs are removed.

  An intercept (1) will only be kept if there are no variables on that side of the formula.

• data: data.frame. Used to extract variables when the formula contains a ".".

• string_out: Whether to return as a string. (Logical)

Examples

# Attach cvms
library(cvms)

# Create formula
f1 <- "y ~ x*z + log(a) + (1|b)"

# Simplify formula (as string)
simplify_formula(f1)

# Simplify formula (as formula)
simplify_formula(as.formula(f1))

Author(s)

Ludvig Renbo Olsen, r-pkgs@ludvigolsen.dk