创建目标组

Question

假设我有以下计划：

test_plan = drake_plan(
foo = target(x + 1, transform = map(x = c(5, 10))),
bar = 42
)

现在我想创建一个新的目标，它包含两个子目标foo_5、foo_10和目标栏。我该怎么做？我觉得这一定非常简单，但我没能找到解决方案。

谢谢！

Answer 1

是的，它既可能又简单。内置的解决方案是使用标签：https://books.ropensci.org/drake/static.html#tags.示例：

library(drake)
drake_plan(
foo = target(
x + 1,
transform = map(x = c(5, 10), .tag_out = group)
),
bar = target(
42,
# You need a transform to use a tag, even for 1 target.
transform = map(tmp = 1, .tag_out = group)
),
baz_map = target(group, transform = map(group)),
baz_combine = target(c(group), transform = combine(group))
)
#> # A tibble: 7 x 2
#>   target         command                
#>   <chr>          <expr>                 
#> 1 foo_5          5 + 1                  
#> 2 foo_10         10 + 1                 
#> 3 bar_1          42                     
#> 4 baz_map_foo_5  foo_5                  
#> 5 baz_map_foo_10 foo_10                 
#> 6 baz_map_bar_1  bar_1                  
#> 7 baz_combine    c(foo_5, foo_10, bar_1)

^{创建于2019-11-16由reprex包(v0.3.0(}