plot_scopus_comparison.R

# Plot output from scopus_comparison()

plot_scopus_comparison = 
  
  function( input,                       # results from `scopus_comparison()`
            pub_count_in_legend = TRUE,  # include publication counts in the legend
            pub_count_in_lines = FALSE   # include publication counts in the lines
  ) {
    
    require(stringr)
    require(ggplot2)
    require(geomtextpath)
    require(ggtext)
    
    # Colour reference query in dark blue
    
    input = input %>% mutate( 
      abridged_query_total_publications = 
        case_when(query_type == 'reference' ~ 
                    abridged_query_total_publications %>%
                    str_replace("^'", "'<span style = 'color: darkblue;'>") %>%
                    str_replace(fixed("' ["), "</span>' ["), 
                  .default = abridged_query_total_publications)
    )
    
    # Sort queries by their average percentage rank throughout search_period
    
    query_order = 
      input %>% arrange(-average_comparison_percentage) %>% 
      pull(abridged_query_total_publications) %>% unique()
    
    input$abridged_query_total_publications = 
      factor(input$abridged_query_total_publications, levels = query_order)
    
    # Based on inputs, tailor appearance of publication counts
    
    colour_variable = ifelse(pub_count_in_legend, 
                             'abridged_query_total_publications',  # if TRUE
                             'abridged_query')  # if FALSE
    
    label_variable = ifelse(pub_count_in_lines, 
                            'abridged_query_total_publications',  # if TRUE
                            'abridged_query')  # if FALSE
    
    # Plot
    input %>%
      
      # Select comparison queries only
      filter(query_type == 'comparison') %>%
      
      ggplot(aes(year, comparison_percentage, colour = get(colour_variable))) +
      scale_x_continuous(breaks = scales::breaks_pretty(10), expand = expansion(0.01)) +
      scale_y_continuous(expand = expansion(0.02), n.breaks = 8,
                         labels = scales::label_percent(accuracy = 1, scale = 1)) +
      geom_line(linewidth = 2, alpha = 0.12, 
                # https://github.com/tidyverse/ggplot2/issues/5728#issuecomment-1970036164
                show.legend = c(colour = TRUE)) + 
      guides(colour = guide_legend(override.aes = list(alpha = 1))) +
      geom_textpath(aes(label = get(label_variable), 
                        color = get(colour_variable)), 
                    linetype = 0, text_smoothing = 40, spacing = 80, 
                    show.legend = FALSE) +
      ggtitle( paste0( 'Comparisons to reference query ',
                       input %>%
                         filter(query_type == 'reference') %>%
                         pull(abridged_query_total_publications) %>% 
                         unique() ) ) +
      ylab(paste0('% relative to ', input[1, 'abridged_query_total_publications'])) +
      xlab('Year') + ylab('Percentage of publications relative to reference query') + 
      theme_minimal() + 
      theme(plot.title.position = 'plot', plot.title = element_markdown(hjust = 0.5), 
            plot.subtitle = element_text(colour = 'grey55', hjust = .5, 
                                         margin = margin(3, 0, 2, 0)),
            axis.title.x = element_text(margin = margin(5, 0, 0, 0, 'pt')), 
            axis.title.y = element_text(margin = margin(0, 6, 0, 0, 'pt')), 
            axis.text.x = element_text(margin = margin(0, 0, 2, 0)), 
            axis.text.y = element_text(margin = margin(0, 0, 0, 2)),
            legend.text = element_text(margin = margin(4, 0, 4, 0)),
            legend.margin = margin(-2, 19, 6, 3), 
            legend.box.margin = margin(5, 1, 0, 1),
            legend.title = element_blank(), legend.direction = 'vertical', 
            legend.key.width = unit(25, 'pt'), legend.position = 'bottom',
            legend.background = element_rect(color = 'grey90', fill = 'grey98'), 
            panel.grid.minor = element_blank(), 
            plot.margin = unit(c(8, 0, 8, 8), 'pt'))
  }