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Interactive Map of SaTScan Clusters

Source: R/map_clusters.R
map_clusters.Rd

Creates an interactive leaflet map displaying detected spatial clusters and their member locations. Clusters are shown as circles with size proportional to the number of locations, colored by statistical significance.

Usage

map_clusters(
  x,
  significance_only = FALSE,
  provider = "CartoDB.Positron",
  cluster_opacity = 0.6,
  color_palette = c("#d73027", "#fc8d59", "#fee08b", "#d9ef8b", "#91cf60", "#1a9850"),
  location_color = "#4575b4",
  show_locations = TRUE,
  popup_vars = NULL,
  verbose = FALSE,
  crs = NULL,
  use_radius = TRUE,
  simple = FALSE,
  ...
)

Arguments

x

A satscan_result object from satscanr().

significance_only

Logical. If TRUE, only display clusters with p-value < 0.05. Default is FALSE (show all clusters).

provider

Character. Leaflet tile provider. Options include "OpenStreetMap", "CartoDB.Positron", "Esri.WorldTopoMap", etc. See https://leaflet-extras.github.io/leaflet-providers/preview/ for full list. Default is "CartoDB.Positron".

cluster_opacity

Numeric between 0 and 1. Opacity of cluster circles. Default is 0.6.

color_palette

Character vector of colors for cluster significance levels. Default is c("#d73027", "#fc8d59", "#fee08b", "#d9ef8b", "#91cf60", "#1a9850") (red to green spectrum).

location_color

Character. Color for individual location markers. Default is "#4575b4" (blue).

show_locations

Logical. If TRUE, show individual location points in addition to cluster boundaries. Default is TRUE.

popup_vars

Character vector. Additional variables from $locations to include in location popups. Default is NULL.

verbose

Logical. If TRUE, show progress messages. Default is FALSE.

crs

Optional. CRS for projecting Cartesian coordinates (e.g., 32618). If provided, coordinates are projected to WGS84 for standard mapping.

use_radius

Logical. If TRUE (default), use the physical radius from SaTScan results for circle size. If FALSE, size by number of locations.

simple

Logical. If TRUE, force a simple coordinate system (pixels) regardless of data type. Useful for debugging or non-geographic scans.

...

Additional arguments passed to leaflet::addCircles() for clusters.

Value

A leaflet map object (htmlwidget) that can be printed to display or saved with htmlwidgets::saveWidget().

Details

The function requires the leaflet package to be installed. If not available, an informative error message is displayed.

Map Layers:

  • Cluster circles: Sized by number of member locations. Fill color represents Relative Risk (RR). Border color and thickness indicate significance.

  • Location points: Individual locations within clusters (if show_locations = TRUE)

  • Popups: Click on clusters or locations for detailed information. Cluster popups include counts, RR, and time period (if available).

Color Scheme:

  • Fill: Mapped to Relative Risk (CLU_RR) using the provided color_palette. If RR is unavailable, falls back to p-value coloring.

  • Border (Stroke): Red and bold for significant clusters (p < 0.05). Gray and thin for non-significant clusters.

Coordinate Detection: The function automatically detects coordinate columns from the locations table:

  • Latitude: lat, latitude, y, LATITUDE

  • Longitude: lon, long, longitude, x, LONGITUDE