USA Map (County)

Authors

[Editor] Hu Zheng;

[Contributors]

Modified

2026-01-17

Note

Hiplot website

This page is the tutorial for source code version of the Hiplot USA Map (County) plugin. You can also use the Hiplot website to achieve no code ploting. For more information please see the following link:

https://hiplot.cn/basic/map-usa-county?lang=en

Setup

  • System Requirements: Cross-platform (Linux/MacOS/Windows)

  • Programming language: R

  • Dependent packages: data.table; jsonlite; ggplot2; RColorBrewer

# Install packages
if (!requireNamespace("data.table", quietly = TRUE)) {
  install.packages("data.table")
}
if (!requireNamespace("jsonlite", quietly = TRUE)) {
  install.packages("jsonlite")
}
if (!requireNamespace("ggplot2", quietly = TRUE)) {
  install.packages("ggplot2")
}
if (!requireNamespace("RColorBrewer", quietly = TRUE)) {
  install.packages("RColorBrewer")
}

# Load packages
library(data.table)
library(jsonlite)
library(ggplot2)
library(RColorBrewer)
sessioninfo::session_info("attached")
─ Session info ───────────────────────────────────────────────────────────────
 setting  value
 version  R version 4.5.2 (2025-10-31)
 os       Ubuntu 24.04.3 LTS
 system   x86_64, linux-gnu
 ui       X11
 language (EN)
 collate  C.UTF-8
 ctype    C.UTF-8
 tz       UTC
 date     2026-01-17
 pandoc   3.1.3 @ /usr/bin/ (via rmarkdown)
 quarto   1.8.27 @ /usr/local/bin/quarto

─ Packages ───────────────────────────────────────────────────────────────────
 package      * version date (UTC) lib source
 data.table   * 1.18.0  2025-12-24 [1] RSPM
 ggplot2      * 4.0.1   2025-11-14 [1] RSPM
 jsonlite     * 2.0.0   2025-03-27 [1] RSPM
 RColorBrewer * 1.1-3   2022-04-03 [1] RSPM

 [1] /home/runner/work/_temp/Library
 [2] /opt/R/4.5.2/lib/R/site-library
 [3] /opt/R/4.5.2/lib/R/library
 * ── Packages attached to the search path.

──────────────────────────────────────────────────────────────────────────────

Data Preparation

# Load data
data <- data.table::fread(jsonlite::read_json("https://hiplot.cn/ui/basic/map-usa-county/data.json")$exampleData$textarea[[1]])
data <- as.data.frame(data)
dt_map <- readRDS(url("https://download.hiplot.cn/ui/basic/map-usa-county/usa.county.rds"))

# Convert data structure
dt_map$Value <- data$value[match(dt_map$county, data$name)]

# View data
head(data)
               name value
1 Lake of the Woods   167
2             Ferry   801
3           Stevens   785
4          Okanogan   783
5      Pend Oreille   796
6          Boundary   126

Visualization

# USA Map (County)
p <- ggplot(dt_map) +
  geom_polygon(aes(x = long, y = lat, group = group, fill = Value),
               alpha = 0.9, size = 0.5) +
  geom_path(aes(x = long, y = lat, group = group), color = "black", size = 0.2) +
  coord_fixed() +
  scale_fill_gradientn(
    colours = colorRampPalette(rev(brewer.pal(11,"RdYlBu")))(500),
    breaks = seq(min(data$value), max(data$value), 
                 round((max(data$value)-min(data$value))/7)),
    name = "Color Key",
    guide = guide_legend(
      direction = "vertical", keyheight = unit(1, units = "mm"),
      keywidth = unit(8, units = "mm"),
      title.position = "top", title.hjust = 0.5, label.hjust = 0.5,
      nrow = 1, byrow = T, reverse = F, label.position = "bottom")) +
  theme(text = element_text(color = "#3A3F4A"),
        axis.text = element_blank(),
        axis.ticks = element_blank(),
        panel.grid.major = element_blank(),
        panel.grid.minor = element_blank(),
        legend.position = "top",
        legend.text = element_text(size = 4 * 1.5, color = "black"),
        legend.title = element_text(size = 5 * 1.5, color = "black"),
        plot.title = element_text(
          face = "bold", size = 5 * 1.5, hjust = 0.5, 
          margin = margin(t = 4, b = 5), color = "black"),
        plot.background = element_rect(fill = "#FFFFFF", color = "#FFFFFF"),
        panel.background = element_rect(fill = "#FFFFFF", color = NA),
        legend.background = element_rect(fill = "#FFFFFF", color = NA),
        plot.margin = unit(c(1.5, 1.5, 1.5, 1.5), "cm")) +
  labs(x = NULL, y = NULL, title = "USA County Map")

p
FigureΒ 1: USA Map (County)