create_dist_list: Generalized distance list as sparse list

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

Generalized distance list as sparse list

Description

This function is an alternative to the package functions that create a square distance matrix of dimension N, with all pairwise distances. In this approach a list of named vectors is returned, where there is one element in the list for each location, and each named vector holds the distance within 'threshold' of the location.

Usage

create_dist_list(
  level,
  threshold,
  st = NULL,
  county = NULL,
  unit = c("miles", "kilometers", "meters")
)

Arguments

level	string either "state", "county", "zip", or "tract"
threshold	numeric value; include in each location-specific named vector only those locations that a within 'threshold' distance units of the target. Reasonable thresholds might be 250 (miles), 50 (miles), 15 (miles) and 3 (miles) for county, zip, and tract, respectively, but these can be adjusted. Note if a different unit other than miles is used, then the user should also adjust this parameter appropriately
st	string; optional to specify a state; if NULL distances are returned for all zip codes, counties, or states in the US
county	string vector of 3-fips to restrict within st; ignored unless level is "tract"
unit	string one of miles (default), kilometers, or meters; this is the unit relevant to the threshold

Value

a named list, where each element, named by a target location, is a named vector of distances that are within 'threshold' 'units' of the target.

Examples

create_dist_list(
  level = "tract",
  threshold = 3,
  st = "MD"
)
create_dist_list(
  level = "county",
  threshold = 50,
  st = "CA",
  unit = "kilometers"
)

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