State of the Union WPM chart

sotu.R

needs(rvest, tidyverse, zoo)

df <- c('minutes', 'words') %>%
  map(function(var) {
    doc <- var %>%
      sprintf(fmt = 'http://www.presidency.ucsb.edu/sou_%s.php') %>%
      read_html()
    doc %>%
      html_node('table tr:nth-of-type(2) table') %>%
      html_table(fill = T) %>%
      select(X1:X4) %>%
      set_names(c('president', 'date', 'type', var)) %>%
      filter(row_number() > 10) %>%
      mutate(date = as.Date(date, '%B %d, %Y'),
             president = ifelse(is.na(date), president, NA) %>%
               na_if('') %>%
               na.locf(F)) %>%
      filter(!is.na(date)) %>%
      select(-type)
  }) %>%
  reduce(left_join) %>%
  rename(duration = minutes) %>%
  mutate_at(vars(words), as.numeric)

df <- df %>%
  mutate(minutes = coalesce(duration %>%
                              str_split(':') %>%
                              map(as.numeric) %>%
                              map_dbl(~ 60 * .x[1] + .x[2] + .x[3] / 60),
                            duration %>%
                              str_extract(' ([0-9]+)') %>%
                              as.numeric()),
         wpm = words / minutes) %>%
  mutate(last_name = map_chr(str_split(president, ' '), last)) %>%
  mutate(president = factor(president, levels = unique(.$president))) %>%
  filter(!is.na(minutes))

colors <- c(gray(.25), gray(.5)) %>%
  rep_len(nlevels(df$president) - 1) %>%
  c('red')

ggplot(df, aes(date, wpm, color = president)) +
  geom_line() +
  geom_point() +
  geom_text(aes(y = 68, label = last_name), size = 3.5,
            data = function(df) df %>%
              group_by(president, last_name) %>%
              summarize(date = mean(date))) +
  scale_color_manual(values = colors) +
  ggtitle('State of the Union: Words per Minute') +
  theme(axis.title = element_blank(),
        legend.pos = 'none',
        plot.margin = margin(80, 40, 80, 40))