Plot signatures to a petition calling for revocation of Article 50

plot_revoke.R

library(rjson)
library(rio)
library(tidyverse)
library(hrbrthemes)
library(ggrepel)

json_to_df <- function(f) {
    json_obj <- tryCatch(fromJSON(file = f),
                         error = function(e) warning(paste0("No data in ",f)))
    
    if (class(json_obj) == "character") { 
        ## pass
        sigs <- NULL
    } else { 
        sigs <- do.call("rbind",
                        lapply(json_obj$data$attributes$signatures_by_constituency,function(x) {
                            data.frame(name = x$name, ons_code = x$ons_code, signature_count = x$signature_count)
                        }))
        
### Get all the things that can be coerced to a one-row data frame
### Except signatures by constituency
        attrs <- names(which(lapply(json_obj$data$attributes, length) == 1))
        attrs <- setdiff(attrs, "signatures_by_constituency")
        attrs <- as.data.frame(json_obj$data$attributes[attrs])
    
        sigs <- merge(sigs, attrs, by = NULL, 
                      suffixes = c(".constituency",".total"),
                      all = T)
        if (nrow(sigs)>0) {
            sigs$id <- gsub(".json","", f)
        }
    }
    
    return(sigs)
}

if (file.exists("241584.json")) { 
    ## pass
} else {
    download.file("https://petition.parliament.uk/petitions/241584.json",
                  destfile = "241584.json")
}

dat <- json_to_df("241584.json")

if (file.exists("BES-2017-General-Election-results-file-v1.0.xlsx")) {
    ## pass
} else  {
    download.file("https://www.britishelectionstudy.com/wp-content/uploads/2017/07/BES-2017-General-Election-results-file-v1.0.xlsx",
                  destfile = "BES-2017-General-Election-results-file-v1.0.xlsx")
}

aux <- import("BES-2017-General-Election-results-file-v1.0.xlsx")

dat <- merge(dat, aux,
             by.x = c("ons_code"),
             by.y = c("ONSConstID"),
             all.x = FALSE,
             all.y = TRUE)

dat <- dat %>%
    mutate(signature_rate = signature_count.constituency / Electorate17,
           Nation = substr(ons_code, 0, 1),
           Nation = case_when(Nation == "E" ~ "England",
                              Nation == "S" ~ "Scotland",
                              Nation == "W" ~ "Wales"),
           party_col = case_when(Winner17 == "Conservative" ~ "#0087dc",
                                 Winner17 == "Labour" ~ "#d50000",
                                 Winner17 == "Liberal Democrat" ~ "#FDBB30",
                                 Winner17 == "Scottish National Party" ~ "#FFF95D",
                                 Winner17 == "Green" ~ "#008066",
                                 Winner17 == "Speaker" ~ "darkgrey",
                                 Winner17 == "Plaid Cymru" ~ "#3F8428"))

mod <- lm(I(signature_rate / 100) ~ remainHanretty, data = dat)

p <- ggplot(dat, aes(x = remainHanretty, y = signature_rate)) +
    geom_point(aes(shape = Nation, fill = party_col),
               alpha = 0.9, size = 4, colour = "black") +
    scale_x_continuous("Remain % in 2016") +
    scale_y_continuous("Signatures as % of 2017 electorate",
                       labels = scales::percent,
                       limits = c(0, NA)) +
    scale_fill_identity("Party") +
    scale_shape_manual(values = c(21, 22, 23)) + 
    geom_smooth(method = "lm", se = FALSE, colour = "black", lty = 2) +
    geom_text_repel(data = subset(dat, signature_rate > 0.05),
                    aes(label = name)) + 
    theme_minimal() +
    theme_ipsum_rc() +
    labs(title = "Constituencies which voted to Remain sign the Article 50 revocation petition at higher rates",
         caption = "Source: petition.parliament.uk; Hanretty (2017), 'Areal interpolation and the UK's referendum on EU membership'") 

ggsave(p, file = "revocation_petition.png", width = 1024/300, height = 512/300, units = "in", dpi = 300, scale = 5)