Chapter 10 Mapping in R

library(tigris)

## To enable caching of data, set `options(tigris_use_cache = TRUE)`
## in your R script or .Rprofile.

library(sf)

## Warning: package 'sf' was built under R version 4.3.3

## Linking to GEOS 3.11.2, GDAL 3.8.2, PROJ 9.3.1; sf_use_s2() is TRUE

library(rvest)
library(leaflet)
library(here)
library(tidyverse)

Load counties of Vermont using Tigris package

vermont_counties |> 
  ggplot() +
  geom_sf(aes(geometry = geometry, fill = AWATER))

Query all states

Map all states

all_states |> 
  ggplot() +
  geom_sf(aes(geometry = geometry, fill = AWATER/ALAND))

Shift the geometry of the coordinates and filter out territories

all_states |> 
  shift_geometry() |> 
  filter(as.numeric(GEOID) < 60) |> 
  ggplot() +
  geom_sf(aes(geometry = geometry, fill = AWATER/ALAND))

10.1 Map alcohol consumption per capita

Scrape alcohol data

url <- "https://wisevoter.com/state-rankings/alcohol-consumption-by-state/"
alcohol <- url |> 
  read_html() |> 
  html_element("table") |> 
  html_table()

Join alcohol to states

all_states_booze <- all_states |> 
  filter(GEOID < 60) |> 
  left_join(alcohol, by = join_by("NAME" == "State"))

all_states_booze <- all_states_booze |> 
  mutate(alcohol_per_cap = as.numeric(str_remove(`Alcohol Consumption Per Capita`, " gal")))

Make a map!

all_states_booze |> 
  shift_geometry() |> 
  filter(as.numeric(GEOID) < 60) |> 
  ggplot() +
  geom_sf(aes(geometry = geometry, fill = alcohol_per_cap)) +
  scale_fill_binned()

Make an interactive map with Leaflet

leaflet() |> 
  addTiles() |> 
  addMarkers(lat= 44.0139,
             lng = -73.1814,
             label = "BiHall",
             popup = "Here we are")

10.2 Map volcanoes

Load the dataset

volcanoes <- read_tsv(here("data_public", "volcano_data.tsv"))

## Rows: 1608 Columns: 11
## ── Column specification ─────────────────────────────────────────────
## Delimiter: "\t"
## chr (7): Search Parameters, Volcano Name, Country, Location, Type, Status, L...
## dbl (4): Volcano Number, Latitude, Longitude, Elevation (m)
## 
## ℹ Use `spec()` to retrieve the full column specification for this data.
## ℹ Specify the column types or set `show_col_types = FALSE` to quiet this message.

head(volcanoes, 5)

## # A tibble: 5 × 11
##   `Search Parameters` `Volcano Number` `Volcano Name`  Country Location Latitude
##   <chr>                          <dbl> <chr>           <chr>   <chr>       <dbl>
## 1 []                                NA <NA>            <NA>    <NA>        NA   
## 2 <NA>                          250010 St. Andrew Str… Papua … Admiral…    -2.38
## 3 <NA>                          250020 Baluan          United… Admiral…    -2.57
## 4 <NA>                          250030 Central Bismar… United… Admiral…    -3.03
## 5 <NA>                              NA Dacht-I-Navar … Afghan… Afghani…    34.0 
## # ℹ 5 more variables: Longitude <dbl>, `Elevation (m)` <dbl>, Type <chr>,
## #   Status <chr>, `Last Known Eruption` <chr>

Map the volcanoes

volcanoes |> 
  leaflet() |> 
  addTiles() |> 
  addMarkers(lat = ~Latitude,
             lng = ~Longitude,
             label = ~`Volcano Name`)

Cluster markers

volcanoes |> 
  leaflet() |> 
  addTiles() |> 
  addMarkers(lat = ~Latitude,
             lng = ~Longitude,
             label = ~`Volcano Name`,
             clusterOptions = markerClusterOptions())

Circles

volcanoes |> 
  leaflet() |> 
  addTiles() |> 
  addCircles(lat = ~Latitude,
             lng = ~Longitude,
             label = ~`Volcano Name`,
             radius = 15000,
             color = "red",
             weight = 1,
             fillOpacity = 0.8)

Map alcohol consumption with leaflet

all_states_booze |> 
  filter(GEOID < 60) |> 
  leaflet() |> 
  addPolygons(label = ~NAME)

Load India data from a shapefile

india_states <- st_read(here("data_public", "indiashp", "Indian_States.shp"))

## Reading layer `Indian_States' from data source 
##   `C:\GitHub\opengisci\wt25_josephholler\data_public\indiashp\Indian_States.shp' 
##   using driver `ESRI Shapefile'
## Simple feature collection with 36 features and 1 field
## Geometry type: MULTIPOLYGON
## Dimension:     XY
## Bounding box:  xmin: 68.18625 ymin: 6.755953 xmax: 97.41529 ymax: 37.07827
## CRS:           NA

Map Indian states with ggplot

india_states |> 
  ggplot() +
  geom_sf() + 
  geom_sf_label(aes(label = st_nm))

Map Indian states with leaflet

india_states |> 
  leaflet() |> 
  addTiles() |> 
  addPolygons()