从 R 中的列表中提取信息

Question

I need to extract specific information from a list in R. My data is 'Benford' object and doesn't seem to be coercible using as_tibble()

My data looks as follows:

library(dplyr)
library(purrr)
library(benford.analysis)

# read data
data = read.csv("https://www2.census.gov/programs-surveys/popest/datasets/2010-2019/counties/totals/co-est2019-alldata.csv", header = T)

# ONLY SELECT THE NUMERIC COLUMN
x <- data %>% 
  select(CENSUS2010POP)

# SPLIT THE DATA INTO TWO GROUPS
x$CITY <- "CITY_A"
x[1500:3193,2] <- "CITY_B"

# SPLIT THE DATA ON THE CITY VARIABLE
dat_list <- split(x,x$CITY)

# APPLY THE BENFORD ANALYSIS TO THE NUMERICAL VALUES PER GROUP
output <- map(dat_list, ~benford(number.of.digits = 1, discrete = TRUE, sign = "positive", data = .x$CENSUS2010POP))

I wish to create a data frame with the CITY name ie CITY_A in one column and the $ MAD.conformity in another for each element in the list.

Any help on how I can pull these elements from my list and store them in a data frame?

Answer 1

You can use purrr::map_dfr() to extract MAD.conformity on each iteration, row-bind the results, and add an .id column containing the names of each element of dat_list . Since dat_list was created by split ting on CITY , the names already correspond to the levels of CITY . (I'm not familiar with the structure of Benford objects, so you may have to tweak the $MAD.conformity index.)

output <- map_dfr(
  dat_list,
  ~ benford(
      number.of.digits = 1, 
      discrete = TRUE, 
      sign = "positive", 
      data = .x$CENSUS2010POP
    )$MAD.conformity,
  .id = "CITY"
)