r - 如何减少 r 中预处理配方对象的大小？

Question

我正在使用 R 食谱包预处理数据集，进行 Yeo-Johnson 转换以使其更加正态分布，然后进行缩放以标准化它。之后，我想减小配方对象的大小，我使用 butcher 包。但这没有帮助。我还尝试手动清理存储数据的"template"，但大小再次保持不变。知道如何减少存储和以后使用的大小吗？这是我面临的现实问题的一个例子:

suppressPackageStartupMessages({
library(dplyr)
library(purrr)
library(recipes)
})

#Lets generate skewed numeric data of size 20 000 x 3 000 (originally I am working with 10x more rows)
n <- 3000

example_list <- 
  1:n %>% 
  map(~abs(rnorm(n = 20000, mean = 0, sd = sample(seq(0.1, 10, length.out = n), size = n))))

names(example_list) <- paste0("col_", 1:n)

example_tibble <- as_tibble(example_list)

#Lets create preprocessing recipe
new_recipe <- 
  recipe( ~ ., data = example_tibble) %>%
  step_YeoJohnson(all_numeric()) %>%
  step_normalize(all_numeric()) %>%
  prep(strings_as_factors = FALSE, retain = FALSE)

#Lets check the structure and size of the recipe object
butcher::weigh(new_recipe)
#> # A tibble: 9,034 x 2
#>    object                     size
#>    <chr>                     <dbl>
#>  1 steps.terms             480.   
#>  2 steps.terms             480.   
#>  3 steps.lambdas             0.232
#>  4 steps.means               0.232
#>  5 steps.sds                 0.232
#>  6 var_info.variable         0.208
#>  7 term_info.variable        0.208
#>  8 last_term_info.variable   0.208
#>  9 template.col_1            0.160
#> 10 template.col_2            0.160
#> # … with 9,024 more rows

lobstr::obj_size(new_recipe)
#> 481,649,536 B

#Lets try to remove unnecessary parts of the object
new_recipe_butchered <- butcher::butcher(new_recipe, verbose = TRUE)
#> ✖ No memory released. Do not butcher.

#Lets check again the size
lobstr::obj_size(new_recipe_butchered)
#> 481,650,016 B

butcher::weigh(new_recipe_butchered)
#> # A tibble: 9,034 x 2
#>    object                     size
#>    <chr>                     <dbl>
#>  1 steps.terms             480.   
#>  2 steps.lambdas             0.232
#>  3 steps.means               0.232
#>  4 steps.sds                 0.232
#>  5 var_info.variable         0.208
#>  6 term_info.variable        0.208
#>  7 last_term_info.variable   0.208
#>  8 template.col_1            0.160
#>  9 template.col_2            0.160
#> 10 template.col_3            0.160
#> # … with 9,024 more rows

#Lets try to remove the template with data
new_recipe_butchered$template <- NULL

butcher::weigh(new_recipe_butchered)
#> # A tibble: 6,034 x 2
#>    object                      size
#>    <chr>                      <dbl>
#>  1 steps.terms             480.    
#>  2 steps.lambdas             0.232 
#>  3 steps.means               0.232 
#>  4 steps.sds                 0.232 
#>  5 var_info.variable         0.208 
#>  6 term_info.variable        0.208 
#>  7 last_term_info.variable   0.208 
#>  8 var_info.role             0.0241
#>  9 var_info.source           0.0241
#> 10 term_info.role            0.0241
#> # … with 6,024 more rows

#Lets check again the size - still the same
lobstr::obj_size(new_recipe_butchered)
#> 481,650,016 B

^{由 reprex package 于 2021 年 6 月 17 日创建(v0.3.0)}

我似乎无法缩小尺寸，有人可以帮忙吗？

Answer 1

此问题已在 {butcher} 的开发版本中得到解决，您可以使用该版本下载

# install.packages("devtools")
devtools::install_github("tidymodels/butcher")

{butcher} 现在将从步骤中删除 terms 环境。

suppressPackageStartupMessages({
library(dplyr)
library(purrr)
library(recipes)
})

n <- 3000

example_list <- 
  1:n %>% 
  map(~abs(rnorm(n = 20000, mean = 0, sd = sample(seq(0.1, 10, length.out = n), size = n))))

names(example_list) <- paste0("col_", 1:n)

example_tibble <- as_tibble(example_list)

new_recipe <- 
  recipe( ~ ., data = example_tibble) %>%
  step_YeoJohnson(all_numeric()) %>%
  step_normalize(all_numeric()) %>%
  prep(strings_as_factors = FALSE, retain = FALSE)

butcher::weigh(new_recipe)
#> # A tibble: 12,033 x 2
#>    object                      size
#>    <chr>                      <dbl>
#>  1 steps.terms             480.    
#>  2 steps.terms             480.    
#>  3 steps.lambdas             0.232 
#>  4 steps.means               0.232 
#>  5 steps.sds                 0.232 
#>  6 var_info.variable         0.208 
#>  7 term_info.variable        0.208 
#>  8 last_term_info.variable   0.208 
#>  9 var_info.role             0.0241
#> 10 var_info.source           0.0241
#> # … with 12,023 more rows

lobstr::obj_size(new_recipe)
#> 481,985,880 B

new_recipe_butchered <- butcher::butcher(new_recipe, verbose = TRUE)
#> ✓ Memory released: '480,170,888 B'

lobstr::obj_size(new_recipe_butchered)
#> 1,814,992 B

butcher::weigh(new_recipe_butchered)
#> # A tibble: 12,033 x 2
#>    object                    size
#>    <chr>                    <dbl>
#>  1 steps.lambdas           0.232 
#>  2 steps.means             0.232 
#>  3 steps.sds               0.232 
#>  4 var_info.variable       0.208 
#>  5 term_info.variable      0.208 
#>  6 last_term_info.variable 0.208 
#>  7 var_info.role           0.0241
#>  8 var_info.source         0.0241
#>  9 term_info.role          0.0241
#> 10 term_info.source        0.0241
#> # … with 12,023 more rows

^{由 reprex package 于 2021 年 6 月 17 日创建(v2.0.0)}