In msperlin/adfeR: Data, exercises and Functions for Book "Analise de Dados Financeiros e Economicos com o R"

# set function that will download the files
read_cranlogs_files <- function(date_in) {
  # Reads log files from http://cran-logs.rstudio.com/
  #
  # ARGS: date_in - date of log data
  require(tidyverse)
  require(lubridate)

  url_dl <- paste0('http://cran-logs.rstudio.com/', year(date_in), '/',
                   date_in, '-r.csv.gz')

  cat('\nReading ', url_dl)

  df <- read_csv(url_dl, col_types = cols())

  return(df)
}

# find out the availabe dates in url
library(rvest)
library(lubridate)

available_links <- read_html('http://cran-logs.rstudio.com/') %>%
  html_nodes(css = 'a') %>%
  html_attr('href')

# only keep links for R download (those with -r.csv.gz pattern)
idx <- str_detect(available_links, '-r.csv.gz')
r_links <- available_links[idx]

# find out dates 
dates_dls <- ymd(basename(r_links))
max_date <- max(dates_dls)

first_date <- as.Date('2020-01-01')
last_date <- as.Date('2020-01-15')

my_dates <- seq(first_date, 
                last_date, 
                by = '1 day')

library(purrr) 
library(tidyverse)

l_out <- map(my_dates, 
             safely(read_cranlogs_files, 
                    otherwise = tibble())) # return empty tibble in case of error

df_cranlogs <- bind_rows(map(l_out, 'result'))

# solution 
my_sol <- names(sort(table(df_cranlogs$country), 
               decreasing = TRUE)[1])

candidates <- unique(na.omit(df_cranlogs$country))
my_answers <- make_random_answers(my_sol, candidates)

Question

No site do Rstudio CRAN logs^[http://cran-logs.rstudio.com/] você encontrará dados sobre as estatísticas de download para a distribuição de base de R na seção Daily R downloads. Usando suas habilidades de programação, importe todos os dados disponíveis entre r first_date e r last_date e agregue-os em uma única tabela. Qual país apresenta a maior contagem de downloads do R?

exams::answerlist(my_answers, markup = "markdown")

Solution

Meta-information

extype: schoice exsolution: r mchoice2string(c(TRUE, FALSE, FALSE, FALSE, FALSE), single = TRUE) exname: "batchgetsymbols dplyr" exshuffle: TRUE

msperlin/adfeR documentation built on March 26, 2021, 3:05 a.m.