This is a thin wrapper around stats::model.matrix() which returns a tibble. Use it to determine how your modelling formula is translated into a matrix, an thence into an equation.

model_matrix(data, formula, ...)

Arguments

data

A data frame

formula

A modelling formula

...

Other arguments passed onto stats::model.matrix()

Value

A tibble.

Examples

model_matrix(mtcars, mpg ~ cyl)
#> # A tibble: 32 x 2 #> `(Intercept)` cyl #> <dbl> <dbl> #> 1 1 6 #> 2 1 6 #> 3 1 4 #> 4 1 6 #> 5 1 8 #> 6 1 6 #> 7 1 8 #> 8 1 4 #> 9 1 4 #> 10 1 6 #> # ... with 22 more rows
model_matrix(iris, Sepal.Length ~ Species)
#> # A tibble: 150 x 3 #> `(Intercept)` Speciesversicolor Speciesvirginica #> <dbl> <dbl> <dbl> #> 1 1 0 0 #> 2 1 0 0 #> 3 1 0 0 #> 4 1 0 0 #> 5 1 0 0 #> 6 1 0 0 #> 7 1 0 0 #> 8 1 0 0 #> 9 1 0 0 #> 10 1 0 0 #> # ... with 140 more rows
model_matrix(iris, Sepal.Length ~ Species - 1)
#> # A tibble: 150 x 3 #> Speciessetosa Speciesversicolor Speciesvirginica #> <dbl> <dbl> <dbl> #> 1 1 0 0 #> 2 1 0 0 #> 3 1 0 0 #> 4 1 0 0 #> 5 1 0 0 #> 6 1 0 0 #> 7 1 0 0 #> 8 1 0 0 #> 9 1 0 0 #> 10 1 0 0 #> # ... with 140 more rows