NICS Firearm Background Checks by Month

### My remix of the "NICS Firearm Background Checks" thread - /u/MetricT
### https://www.reddit.com/r/dataisbeautiful/comments/ie4wxu/fbi_firearm_background_checks_over_time_oc/
###
### First, you need to convert the data from this pdf into something useable:
###
###   https://www.fbi.gov/file-repository/nics_firearm_checks_-_month_year.pdf/view
###
### I used Tabula [https://tabula.technology/] to scan the PDF and save it as a spreadsheet
### If you do this, export it as "stream" instead of the default "lattice" to get it in the
### correct form.
###
### Fire up the .csv Tabula made in Excel and trim off the "Total" column, although strictly
### speaking it wasn't necessary.
###
### At this point, R should handle the rest...
###
### The "geom_inauguration_dates" is a function I wrote.  I haven't published it yet because
### it's not a true geom_* object, it just uses a similar function call.  If anyone wants to
### help me turn it into an actual geom_ object, hit me up...

data <-
  "NICS_Firearm_Background_Checks.csv" %>%
  read_csv(col_names = TRUE, col_types = "dnnnnnnnnnnnn") %>%
  pivot_longer(-Year, names_to = "Month", values_to = "NICS_Firearm_Background_Checks") %>%
  filter(!is.na(NICS_Firearm_Background_Checks)) %>%
  filter(Year >= 1999) %>%
  mutate(yearmonth = yearmonth(paste(Year, " ", Month))) %>%
  select(yearmonth, NICS_Firearm_Background_Checks)

model <-
  data %>%
  as_tsibble(index = "yearmonth") %>%
  model(STL(NICS_Firearm_Background_Checks ~ trend(window = 90))) %>%
  components()

graph <-
  model %>%
  select(yearmonth, NICS_Firearm_Background_Checks, trend, season_adjust) %>%
  rename(values = NICS_Firearm_Background_Checks) %>%
  filter(yearmonth >= yearmonth("1999 Jan")) %>%
  ggplot(aes(x = yearmonth(yearmonth))) +
  geom_point(aes(y = values), alpha = 0.2) +
  geom_line(aes(y = trend * 0.85), size = 0.8, linetype = "dotted", color = "black") +
  geom_line(aes(y = season_adjust), size = 1.2, color = "darkseagreen4") +
  labs(x = "Date",
       y = "# of Background Checks",
       title = "NICS Firearm Background Checks by Month") +
  scale_y_continuous(labels = scales::comma) +
  theme_bw() +
  geom_inauguration_dates(min(model$yearmonth), max(model$yearmonth), 3500000) +
  theme(legend.position = "none")
print(graph)