# load libraries
library(sf)
library(dplyr)
# Import data
german_districts <-
sf::read_sf("./data/VG250_KRS.shp") |>
sf::st_transform(3035) |>
dplyr::select(AGS, GEN)
attributes_districts <-
readr::read_delim("./data/attributes_districts.csv", delim = ";")
# Join data and transform
german_districts_enhanced <-
german_districts |>
dplyr::left_join(attributes_districts, by = "AGS")
# Check
sf::st_crs(german_districts_enhanced)
head(german_districts_enhanced, 2)Exercise 4_2: Subsetting and Linking
Introduction to Geospatial Techniques for Social Scientists in R
Exercises
Solutions
Tip✅ Solution 2
# filter Cologne
cologne <-
german_districts |>
dplyr::filter(AGS == "05315")
# filter surrounding districts, append with Cologne data and select the charger column
cologne_sur <-
german_districts |>
dplyr::filter(lengths(sf::st_touches(german_districts, cologne)) > 0) |>
dplyr::bind_rows(cologne)
# one pipe to rule them all
cologne_sur_enhanced <-
readr::read_delim("./data/charging_points_ger.csv", delim =";") |>
dplyr::filter(!is.na(longitude) & !is.na(latitude)) |>
sf::st_as_sf(coords = c("longitude", "latitude"), crs = 4326) |>
sf::st_transform(crs = 3035) |>
sf::st_join(cologne_sur, join = sf::st_within) |>
dplyr::group_by(AGS) |>
dplyr::summarise(charger_count = dplyr::n()) |>
sf::st_drop_geometry() |>
dplyr::left_join(cologne_sur, y = _, by = "AGS") |>
dplyr::left_join(
attributes_districts |>
dplyr::select(AGS, population),
by = "AGS"
) |>
dplyr::mutate(charger_dens = (charger_count*1000) / population)
# plot
cologne_sur_enhanced |>
dplyr::select(charger_count, charger_dens) |>
plot()Warning: One or more parsing issues, call `problems()` on your data frame for details,
e.g.:
dat <- vroom(...)
problems(dat)Rows: 60560 Columns: 7
── Column specification ────────────────────────────────────────────────────────
Delimiter: ";"
chr (3): operator, federal_state, type
dbl (4): latitude, longitude, power_kw, num_plugs
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.