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.
Arguments
- data
A data frame
- formula
A modelling formula
- ...
Other arguments passed onto
stats::model.matrix()
Examples
model_matrix(mtcars, mpg ~ cyl)
#> # A tibble: 32 × 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
#> # ℹ 22 more rows
model_matrix(iris, Sepal.Length ~ Species)
#> # A tibble: 150 × 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
#> # ℹ 140 more rows
model_matrix(iris, Sepal.Length ~ Species - 1)
#> # A tibble: 150 × 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
#> # ℹ 140 more rows