Declare a custom step

With declare_step, you can include any function that takes data as one of its arguments and returns data in a design declaration. The first argument is always a "handler", which is the name of the data-in, data-out function. For handy data manipulations use declare_step(fabricate, ...).

Usage

declare_step(
  ...,
  handler = function(data, ...f, ...) ...f(data, ...),
  label = NULL
)

Arguments

...

arguments to be captured, and later passed to the handler

handler

a tidy-in, tidy-out function

label

a string describing the step

Value

A function that returns a data.frame.

Examples

population <- declare_model(N = 5, noise = rnorm(N))
manipulate <- declare_step(fabricate, noise_squared = noise^2, zero = 0)

design <- population + manipulate
draw_data(design)
#>   ID      noise noise_squared zero
#> 1  1  0.1458385    0.02126886    0
#> 2  2 -0.8385436    0.70315531    0
#> 3  3 -1.5228416    2.31904656    0
#> 4  4  0.6315840    0.39889838    0
#> 5  5  0.1181995    0.01397113    0