formulize

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If you:

then formulize may be for you. Formulize is very new, but you can still install formulize from github with:

# install.packages("devtools")
devtools::install_github("alexpghayes/formulize")

Adding a formula or recipe interface

Suppose you want to add a formula interface to an existing modelling function, say cv.glmnet. Then you could do the following

library(recipes)
library(glmnet)
library(formulize)

glmnet_cv <- formulize(cv.glmnet)

glmnet_model <- glmnet_cv(mpg ~ drat + hp - 1, mtcars)
predict(glmnet_model, head(mtcars))
#>                          1
#> Mazda RX4         22.35385
#> Mazda RX4 Wag     22.35385
#> Datsun 710        22.85056
#> Hornet 4 Drive    19.97909
#> Hornet Sportabout 17.72895
#> Valiant           19.24104

Similarly glmnet_cv works with recipe objects like so

rec <- recipe(mpg ~ drat + hp, data = mtcars)

glmnet_model2 <- glmnet_cv(rec, mtcars)
predict(glmnet_model2, head(mtcars))
#>             1
#> [1,] 22.35392
#> [2,] 22.35392
#> [3,] 22.85062
#> [4,] 19.97897
#> [5,] 17.72884
#> [6,] 19.24084

You may also be interested in the more dangerous exciting version genericize, which you should call for its side effects.

genericize(cv.glmnet)

form <- mpg ~ drat + hp - 1
X <- model.matrix(form, mtcars)
y <- mtcars$mpg

set.seed(27)
mat_model <- cv.glmnet(X, y, intercept = TRUE)

set.seed(27)
frm_model <- cv.glmnet(form, mtcars, intercept = TRUE)

set.seed(27)
rec_model <- cv.glmnet(rec, mtcars, intercept = TRUE)

predict(mat_model, head(X))
#>                          1
#> Mazda RX4         22.25028
#> Mazda RX4 Wag     22.25028
#> Datsun 710        22.73249
#> Hornet 4 Drive    20.01959
#> Hornet Sportabout 17.84620
#> Valiant           19.33092
predict(frm_model, head(mtcars))
#>                          1
#> Mazda RX4         22.25028
#> Mazda RX4 Wag     22.25028
#> Datsun 710        22.73249
#> Hornet 4 Drive    20.01959
#> Hornet Sportabout 17.84620
#> Valiant           19.33092
predict(rec_model, head(mtcars))
#>             1
#> [1,] 22.25035
#> [2,] 22.25035
#> [3,] 22.73255
#> [4,] 20.01946
#> [5,] 17.84608
#> [6,] 19.33070

This creates a new S3 generic cv.glmnet, sets the provided function as the default method (cv.glmnet.default), and adds methods cv.glmnet.formula and cv.glmnet.recipe using formulize.

This will mask cv.glmnet and features no safety checks because safety isn’t fun.

Caveats