prepare_map_data: Prepare cluster result and shape file for mapping

In gsClusterDetect: Utilities for Geo-Spatial Cluster Detection and Significance Classification

Prepare cluster result and shape file for mapping

Description

Function ingest an clusters object as returned by find_clusters(), a shape file, and a unique identifier for the locations in that shape file, and prepares these objects for mapping.

Usage

prepare_map_data(cl, s, s_id, label_id = NULL, point_crs = NULL)

Arguments

cl	an object of class "clusters" as returned by find_clusters()
s	shape file; must be of class sf
s_id	string unique identifier of 's'
label_id	string column of 's' that indicates display label for the row in 's' (default is NULL)
point_crs	optional coordinate reference system used to compute representative points when 's' is in longitude/latitude coordinates. If 'NULL', EPSG:3857 is used as a general-purpose fallback. The resulting points are transformed back to the CRS of 's' before plotting

Examples

# example code
# get some data
dd <- example_count_data[, max(date)]
# get a distance matrix
dm <- create_dist_list("county", 50, st = "OH")
# find the clusters
cl <- find_clusters(
  cases = example_count_data,
  detect_date = dd,
  distance_matrix = dm
)
# get shape file
ohio_shape <- tigris::counties("OH", cb = TRUE, class = "sf")

# prepare map data
md <- prepare_map_data(cl, ohio_shape, "GEOID")
md <- prepare_map_data(cl, ohio_shape, "GEOID", label_id = "NAME")

gsClusterDetect documentation built on July 27, 2026, 5:09 p.m.