Simple Features Data

This lesson is called Simple Features Data, part of the Mapping with R course. This lesson is called Simple Features Data, part of the Mapping with R course.

Transcript

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View code shown in video

options(pillar.sigfig = 7)

library(sf)
library(tidyverse)

wyoming <-
  read_sf("https://raw.githubusercontent.com/rfortherestofus/mapping-with-r-v2/refs/heads/main/data/wyoming.geojson")

wyoming

ggplot() +
  geom_sf(data = wyoming)

wyoming_one_ev_station <-
  read_sf("https://raw.githubusercontent.com/rfortherestofus/mapping-with-r-v2/refs/heads/main/data/wyoming-one-ev-station.geojson")

wyoming_one_ev_station

ggplot() +
  geom_sf(data = wyoming) +
  geom_sf(data = wyoming_one_ev_station)

wyoming_highway_30 <-
  read_sf("https://raw.githubusercontent.com/rfortherestofus/mapping-with-r-v2/refs/heads/main/data/wyoming-highway-30.geojson")

wyoming_highway_30

ggplot() +
  geom_sf(data = wyoming) +
  geom_sf(data = wyoming_highway_30)

rhode_island <-
  read_sf("https://raw.githubusercontent.com/rfortherestofus/mapping-with-r-v2/refs/heads/main/data/rhode-island.geojson")

rhode_island

ggplot() +
  geom_sf(data = rhode_island)

wyoming_all_ev_stations <-
  read_sf("https://raw.githubusercontent.com/rfortherestofus/mapping-with-r-v2/refs/heads/main/data/wyoming-all-ev-stations.geojson")

wyoming_all_ev_stations

ggplot() +
  geom_sf(data = wyoming) +
  geom_sf(data = wyoming_all_ev_stations)

wyoming_roads <-
  read_sf("https://raw.githubusercontent.com/rfortherestofus/mapping-with-r-v2/refs/heads/main/data/wyoming-roads.geojson")

wyoming_roads

ggplot() +
  geom_sf(data = wyoming) +
  geom_sf(data = wyoming_roads)

wyoming

rhode_island

rhode_island_bounding_box <-
  rhode_island |>
  st_bbox() |>
  st_as_sfc() |>
  st_sf() |>
  rename(geometry = st_as_sfc.st_bbox.rhode_island..)

ggplot() +
  geom_sf(data = rhode_island) +
  geom_sf(
    data = rhode_island_bounding_box,
    color = "red",
    linewidth = 1,
    fill = NA
  )

wyoming

wyoming_different_projection <-
  wyoming |>
  st_transform(5070)

wyoming_different_projection

wyoming |>
  ggplot() +
  geom_sf()

wyoming_different_projection |>
  ggplot() +
  geom_sf()

wyoming

wyoming_coordinates <-
  wyoming |>
  st_coordinates() |>
  as_tibble() |>
  rename(longitude = X, latitude = Y) |>
  select(longitude, latitude)

wyoming_coordinates

wyoming_coordinates |>
  ggplot(
    aes(
      x = longitude,
      y = latitude
    )
  ) +
  geom_point()

Your Turn

Run the following code in order to import an sf object called africa.

library(sf)

africa <-
  read_sf(
    "https://raw.githubusercontent.com/rfortherestofus/mapping-with-r-v2/refs/heads/main/data/africa.geojson"
  )

Examine your object, ensuring you can identify its geometry type, dimensions, bounding box, coordinate reference system and geometry column.

If you want to, try making a static map with the geom_sf() function from ggplot and/or an interactive map with the mapview() function from the {mapview} package.

Learn More

My book, R for the Rest of Us: A Statistics-Free Introduction, has a chapter on mapping that you may find interesting. If you want to go deep on simple features data, this vignette from the {sf} package is for you.

Have any questions? Put them below and we will help you out!

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Jesco Brown • September 28, 2025

When exploring the africa dataset, i did not have to rename the column to geometry as the lesson did in the wyoming example. why?
also what does the st_ in all the functions stand for?

David Keyes Founder • September 29, 2025

You don't have to rename the geometry column, as it is already called that. For the Wyoming example, where exactly are you talking about when I rename the column?

On the question about st_, I'm not sure if it stands for anything, but it is a prefix that tells you all of the functions are from the {sf} package.