R/get_cell_size.R

In mpjashby/sfhotspot: Hot-Spot Analysis with Simple Features

#' Extract cell size from grid
#'
#' @param grid SF object containing polygons.
#'
#' @return Numeric cell size.
#'
#' @noRd

get_cell_size <- function(grid) {

  # Validate inputs
  validate_sf(
    grid,
    label = "grid",
    type = c("POLYGON", "MULTIPOLYGON"),
    call = rlang::caller_env()
  )

  # Extract cell size from grid
  centroids <- suppressWarnings(sf::st_centroid(grid))
  cell_size <- as.numeric(mean(sf::st_distance(
    centroids,
    centroids[sf::st_nearest_feature(centroids), ],
    by_element = TRUE
  )))

  cell_size

}