当某些变量缺少标签时在 R 中提取 Stata 标签

extracting Stata labels in R when some variables are missing labels

我正在处理带有变量名称和标签的大型 Stata 文件。我需要这些标签来理解每个变量是什么。

我一直在用

df[] %>% map_chr(~attributes(.)$label)

提取变量名称和相关标签。不幸的是,一些数据集的变量缺少任何标签(见下图)。

这意味着当我尝试上面的代码时,我只是得到一个错误。

Error: Result 1 is not a length 1 atomic vector

理想情况下,我有一种方法可以调用所有缺失的标签 "NA" 或什么都不调用,因此我可以获得如下输出:

#

仅当具有缺失值的变量根本没有标签,但仍包含在内时。

您可以只执行 map 后跟 map_chr 的传递,即

library(haven)
library(dplyr)
library(purrr)

dat <- read_dta("http://data.princeton.edu/wws509/datasets/salary.dta")

attributes(dat$yr)$label <- NULL
dat %>% map_chr(~attributes(.)$label)
# Error: Result 3 is not a length 1 atomic vector

dat %>% 
  map(~attributes(.)$label) %>%
  map_chr(~ifelse(is.null(.), NA, .))
#                                  sx                                  rk 
#          "Sex (coded 1 for female)"                              "Rank" 
#                                  yr                                  dg 
#                                  NA             "Highest degree earned" 
#                                  yd                                  sl 
# "Years since highest degree earned"   "Academic year salary in dollars"

或等效

dat %>%
  map(~attributes(.)) %>%
  map_chr("label", .default = NA)

我觉得 purrr 的严格性妨碍了你在这里想要的东西。如果你只是lapply()(或purrr::map()),你会得到一个列表,非常适合使用:

# get an example Stata dataset
webuse::webuse("auto")

# drop the label on `price`
attr(auto$price, "label") <- NULL

# get all of the labels as a list
labels <- lapply(auto, attr, "label")

这给你:

> str(labels)
List of 12
 $ make        : chr "Make and Model"
 $ price       : NULL
 $ mpg         : chr "Mileage (mpg)"
 $ rep78       : chr "Repair Record 1978"
 $ headroom    : chr "Headroom (in.)"
 $ trunk       : chr "Trunk space (cu. ft.)"
 $ weight      : chr "Weight (lbs.)"
 $ length      : chr "Length (in.)"
 $ turn        : chr "Turn Circle (ft.) "
 $ displacement: chr "Displacement (cu. in.)"
 $ gear_ratio  : chr "Gear Ratio"
 $ foreign     : chr "Car type"

如果您愿意为没有标签的变量排除标签,您可以unlist():

> unlist(labels)
                    make                      mpg                    rep78                 headroom 
        "Make and Model"          "Mileage (mpg)"     "Repair Record 1978"         "Headroom (in.)" 
                   trunk                   weight                   length                     turn 
 "Trunk space (cu. ft.)"          "Weight (lbs.)"           "Length (in.)"     "Turn Circle (ft.) " 
            displacement               gear_ratio                  foreign 
"Displacement (cu. in.)"             "Gear Ratio"               "Car type"