ddist_sf: Calculate dyadic distances between points 'i' and 'j' in a...

In jvieroe/dyadicdist: Compute Dyadic Distances

Description

This function calculates the geodesic distance between any dyads (pairs of points i and j) in a spatial dataset and stores the result in a long tibble

Usage

ddist_sf(
  data = NULL,
  id = NULL,
  crs_transform = FALSE,
  new_crs = NULL,
  diagonal = TRUE,
  duplicates = TRUE
)

Arguments

data	an object of class sf ("sf" "data.frame" or "sf" "tbl_df" "tbl" "data.frame")
id	a variable uniquely identifying geospatial points. Can be of type numeric, integer, character, or factor
crs_transform	a logical value indicating whether to transform the CRS. Defaults to FALSE
new_crs	a valid EPSG for a new CRS. See rgdal::make_EPSG() or https://epsg.org/home.html
diagonal	a logical value. Keep the diagonal component in the distance matrix with dyads (i,i) and distance zero? Defaults to TRUE
duplicates	a logical value. Keep "identical" dyads (i,j) and (j,i)? Defaults to TRUE. If set to FALSE, only one observation per dyad is kept. Note that this uses rowwise and makes the ddist function considerably more time-consuming

Value

a long tibble with dyads and dyadic distances incl. a distance unit indicator

Author(s)

Jeppe Vierø

Examples

library(tibble)
df <- tibble::tribble(
~city_name, ~idvar, ~latitude, ~longitude,
"copenhagen", 5, 55.68, 12.58,
"stockholm", 2, 59.33, 18.07,
"oslo", 51, 59.91, 10.75
) %>% sf::st_as_sf(coords = c("longitude", "latitude"), crs = 4326)
ddist_sf(data = df, id = "idvar")

jvieroe/dyadicdist documentation built on Jan. 21, 2022, 8:43 a.m.