fmap_plot: Fresnel Map

In lbuk/fmap: Fresnel Maps with Equal-Area Concentric Circular Zones (or Annuli)

Fresnel Map

Description

Function for plotting Fresnel Maps, or thematic maps that visualise spatial data to the level of equal-area concentric circular zones (or annuli).

Usage

fmap_plot(
  ncircles,
  radius_inner = NULL,
  radius_outer = NULL,
  geo_points,
  lat = NULL,
  lon = NULL,
  geo_centre = NULL,
  geo_centres = NULL,
  id_var = NULL,
  sum = NULL,
  mean = NULL,
  median = NULL,
  count = F
)

Arguments

ncircles	Number of concentric circular zones of equal area (i.e. Fresnel circles) including the inner circle and annuli
radius_inner	Radius of innermost Fresnel circle in metres
radius_outer	Radius of outermost Fresnel circle in metres
geo_points	A spatial dataset of points to aggregate
lat	Latitude of the centre of the Fresnel Map
lon	Longitude of the centre of the Fresnel Map
geo_centre	A spatial dataset containing the coordinates of the centre of the Fresnel Map
geo_centres	A spatial dataset containing the coordinates of the centres of each separate Fresnel Map
id_var	Variable from geo_centres containing the location ID
sum	Variable from geo_points for calculating sum
mean	Variable from geo_points for calculating mean
median	Variable from geo_points for calculating median
count	Count the number of points from geo_points. Input TRUE to count points. Defaults to FALSE

Value

A Fresnel Map based on aggregations of points-based data and visualised using tmap.

Examples

library(sf)
library(dplyr)

# Load the sf datasets of cholera deaths and Soho pumps
data(cholera_deaths, soho_pumps)

# Filter the Broad Street Pump from the Soho pumps dataset
bstreet_pump <- soho_pumps %>% filter(soho.pump == "Broad Street")

# The Fresnel Map based on the Broad Street Pump
fmap_plot(radius_inner = 125, ncircles = 8, geo_centre = bstreet_pump, geo_points = cholera_deaths, sum = "cholera.deaths")

# Map of multiple Fresnel Maps based on each Soho pump
fmap_plot(radius_inner = 125, ncircles = 2, geo_centres = soho_pumps, id_var = "soho.pump", geo_points = cholera_deaths, sum = "cholera.deaths")

lbuk/fmap documentation built on Nov. 23, 2024, 12:47 p.m.