Compare the committer date of two git repositories

library(dplyr)
library(ggplot2)
library(magrittr)
library(readr)

time_zone <- "+0800"
data1 <- read_tsv("git-legacy-homebrew.tsv")
data2 <- read_tsv("git-brew.tsv")

merged_data <- right_join(data1, data2, by = c("Author_date", "Subject"))

sh <- merged_data %$% c(
    "case $GIT_COMMIT in",
    paste0(SHA1.x, ") export GIT_COMMITTER_DATE='", Committer_date.y, " ", time_zone, "';;"),
    "esac") %>% data_frame

write_tsv(merged_data, "env-filter.tsv")
write_tsv(sh, "env-filter.sh", col_names = FALSE)

ggplot(merged_data) +
  aes(x = Committer_date.x, y = Committer_date.y) +
  xlab("Committer date of Homebrew/legacy-homebrew") +
  ylab("Commiter date of Homebrew/brew") +
  geom_point()