R/plot_majmin.R

In redist: Simulation Methods for Legislative Redistricting

#' Majority Minority Plots
#'
#' @param grouppercent output from redist.group.percent
#' @param type string in 'hist', 'toptwo', or 'box'
#' @param title ggplot title
#'
#' @importFrom ggplot2 geom_histogram theme_bw geom_point geom_vline geom_hline annotate geom_boxplot
#' @importFrom dplyr arrange desc first nth summarise
#'
#' @return ggplot
#' @concept plot
#' @export
redist.plot.majmin <- function(grouppercent, type = "hist", title = "") {

    if (type == "hist") {
        mm <- colSums(grouppercent > 0.5)

        p <- tibble(mm = mm) %>%
            ggplot(aes(x = mm)) +
            geom_histogram() +
            theme_bw() +
            labs(x = "Minority Majority Districts", y = "Count", title = title)

        return(p)

    } else if (type == "toptwo") {
        tibble(blk_pct = c(grouppercent), district = rep(1:nrow(grouppercent), ncol(grouppercent)),
            nloop = rep(1:ncol(grouppercent), each = nrow(grouppercent))) %>%
            group_by(nloop) %>%
            arrange(desc(blk_pct), .by_group = TRUE) %>%
            mutate(group_id = row_number()) %>%
            filter(group_id <= 2) %>%
            summarise(first_blk = first(tot_blk_pct), second_blk = nth(tot_blk_pct, n = 2)) %>%
            ggplot(aes(x = first_blk, y = second_blk)) +
            geom_point() +
            geom_vline(xintercept = .5, color = "blue", linetype = "dotted") +
            geom_hline(yintercept = .5, color = "blue", linetype = "dotted") +
            labs(x = "Larger Minority Percent", y = "Smaller Minority Percent") +
            theme_bw() +
            annotate("rect", xmin = 0.5, ymin = 0.5, xmax = 1, ymax = 1, alpha = 0.2)


    } else if (type == "box") {
        tibble(blk_pct = c(grouppercent), district = rep(1:nrow(grouppercent), ncol(grouppercent)),
            nloop = rep(1:ncol(grouppercent), each = nrow(grouppercent))) %>%
            group_by(district) %>%
            mutate(blk_pct = sort(blk_pct)) %>%
            ungroup() %>%
            ggplot(aes(x = district, y = blk_pct, group = district)) %>%
            geom_boxplot() +
            theme_bw() +
            labs(x = "Districts, Sorted by Minority Percent", y = "Minority Percent")

    }


    stop("No available type specified.")
}


globalVariables(c("nloop", "blk_pct", "group_id", "tot_blk_pct", "first_blk", "second_blk", "district"))