我目前正在为一个项目评估drake，并且我想知道是否存在以编程方式生成包含触发器的计划目标或计划的一部分的方法。
下面是我的理想用例/示例代码，但是由于drake将我的功能用作命令，并且不读取触发器，因此我在尝试使其工作方面遇到问题。
drake_fetch_remote_data <- function(remote_path, ...) {
hash = retrive_remote_hash(remote_path)
target(
command = fetch_remote_data(remote_path),
trigger = trigger(
change = hash
)
)
}
plan <- drake_plan(
df1 = drake_fetch_remote_data('path1'),
df2 = drake_fetch_remote_data('path2'),
)
#> # A tibble: 2 x 2
#> target command
#> <chr> <expr>
#> 1 df1 drake_fetch_remote_data("path1")
#> 2 df2 drake_fetch_remote_data("path2")
以下代码包括触发器。
drake_fetch_remote_data <- function(remote_path, ...) {
hash = retrive_remote_hash(remote_path)
target(
command = fetch_remote_data(remote_path),
trigger = trigger(
change = hash
)
)
}
plan <- drake_plan(
df1 = target(
command = fetch_remote_data('path1'),
trigger = trigger(change = lookup_hash('path1'))
)
)
# A tibble: 1 x 3
# target command trigger
# <chr> <expr> <expr>
# 1 df1 fetch_remote_data("path1") trigger(change = lookup_hash("path1"))
答案 0 :(得分：1)
绝对！有几种方法。请查看https://ropenscilabs.github.io/drake-manual/plans.html#large-plans。
library(drake)
# Write out paths one by one.
drake_plan(
df = target(
drake_fetch_remote_data(path),
transform = map(path = c("path1", "path2"))
)
)
#> # A tibble: 2 x 2
#> target command
#> <chr> <expr>
#> 1 df_path1 drake_fetch_remote_data("path1")
#> 2 df_path2 drake_fetch_remote_data("path2")
# Or generate a large collection of paths.
drake_plan(
df = target(
drake_fetch_remote_data(path),
transform = map(path = !!paste0("path", seq_len(10)))
)
)
#> # A tibble: 10 x 2
#> target command
#> <chr> <expr>
#> 1 df_path1 drake_fetch_remote_data("path1")
#> 2 df_path2 drake_fetch_remote_data("path2")
#> 3 df_path3 drake_fetch_remote_data("path3")
#> 4 df_path4 drake_fetch_remote_data("path4")
#> 5 df_path5 drake_fetch_remote_data("path5")
#> 6 df_path6 drake_fetch_remote_data("path6")
#> 7 df_path7 drake_fetch_remote_data("path7")
#> 8 df_path8 drake_fetch_remote_data("path8")
#> 9 df_path9 drake_fetch_remote_data("path9")
#> 10 df_path10 drake_fetch_remote_data("path10")
# You can reference a variable that stores the paths.
paths <- paste0("path", seq_len(10))
drake_plan(
df = target(
drake_fetch_remote_data(path),
transform = map(path = !!paths)
)
)
#> # A tibble: 10 x 2
#> target command
#> <chr> <expr>
#> 1 df_path1 drake_fetch_remote_data("path1")
#> 2 df_path2 drake_fetch_remote_data("path2")
#> 3 df_path3 drake_fetch_remote_data("path3")
#> 4 df_path4 drake_fetch_remote_data("path4")
#> 5 df_path5 drake_fetch_remote_data("path5")
#> 6 df_path6 drake_fetch_remote_data("path6")
#> 7 df_path7 drake_fetch_remote_data("path7")
#> 8 df_path8 drake_fetch_remote_data("path8")
#> 9 df_path9 drake_fetch_remote_data("path9")
#> 10 df_path10 drake_fetch_remote_data("path10")
# Shorter target names.
ids = as.numeric(seq_len(10))
paths <- paste0("path", seq_len(10))
drake_plan(
df = target(
drake_fetch_remote_data(path),
transform = map(path = !!paths, id = !!ids, .id = id)
)
)
#> # A tibble: 10 x 2
#> target command
#> <chr> <expr>
#> 1 df_1 drake_fetch_remote_data("path1")
#> 2 df_2 drake_fetch_remote_data("path2")
#> 3 df_3 drake_fetch_remote_data("path3")
#> 4 df_4 drake_fetch_remote_data("path4")
#> 5 df_5 drake_fetch_remote_data("path5")
#> 6 df_6 drake_fetch_remote_data("path6")
#> 7 df_7 drake_fetch_remote_data("path7")
#> 8 df_8 drake_fetch_remote_data("path8")
#> 9 df_9 drake_fetch_remote_data("path9")
#> 10 df_10 drake_fetch_remote_data("path10")
由reprex package（v0.2.1）于2019-05-03创建
触发器可以像命令一样使用分组变量。
library(drake)
ids <- as.numeric(seq_len(10))
paths <- paste0("path", seq_len(10))
drake_plan(
df = target(
fetch_data(path),
trigger = trigger(change = hash_data(path)),
transform = map(path = !!paths, id = !!ids, .id = id)
)
)
#> # A tibble: 10 x 3
#> target command trigger
#> <chr> <expr> <expr>
#> 1 df_1 fetch_data("path1") trigger(change = hash_data("path1"))
#> 2 df_2 fetch_data("path2") trigger(change = hash_data("path2"))
#> 3 df_3 fetch_data("path3") trigger(change = hash_data("path3"))
#> 4 df_4 fetch_data("path4") trigger(change = hash_data("path4"))
#> 5 df_5 fetch_data("path5") trigger(change = hash_data("path5"))
#> 6 df_6 fetch_data("path6") trigger(change = hash_data("path6"))
#> 7 df_7 fetch_data("path7") trigger(change = hash_data("path7"))
#> 8 df_8 fetch_data("path8") trigger(change = hash_data("path8"))
#> 9 df_9 fetch_data("path9") trigger(change = hash_data("path9"))
#> 10 df_10 fetch_data("path10") trigger(change = hash_data("path10"))
由reprex package（v0.2.1）于2019-05-06创建
为更加清楚起见，您还可以将命令作为命名参数提供给target()。
library(drake)
ids <- as.numeric(seq_len(10))
paths <- paste0("path", seq_len(10))
drake_plan(
df = target(
command = fetch_data(path), # now named for clarity
trigger = trigger(change = hash_data(path)),
transform = map(path = !!paths, id = !!ids, .id = id)
)
)
#> # A tibble: 10 x 3
#> target command trigger
#> <chr> <expr> <expr>
#> 1 df_1 fetch_data("path1") trigger(change = hash_data("path1"))
#> 2 df_2 fetch_data("path2") trigger(change = hash_data("path2"))
#> 3 df_3 fetch_data("path3") trigger(change = hash_data("path3"))
#> 4 df_4 fetch_data("path4") trigger(change = hash_data("path4"))
#> 5 df_5 fetch_data("path5") trigger(change = hash_data("path5"))
#> 6 df_6 fetch_data("path6") trigger(change = hash_data("path6"))
#> 7 df_7 fetch_data("path7") trigger(change = hash_data("path7"))
#> 8 df_8 fetch_data("path8") trigger(change = hash_data("path8"))
#> 9 df_9 fetch_data("path9") trigger(change = hash_data("path9"))
#> 10 df_10 fetch_data("path10") trigger(change = hash_data("path10"))
由reprex package（v0.2.1）于2019-05-06创建