neighborhood_gh_search {spatialrisk}

Search for coordinates with higher concentrations within geohash

Description

highest_concentration returns the highest concentration within a portfolio based on grid points. However, higher concentrations can be found within two grid points. 'neighborhood_gh_search()' looks for even higher concentrations in the neighborhood of the grid points with the highest concentrations. This optimization is done by means of Simulated Annealing.

Usage

neighborhood_gh_search(
  hc,
  highest_geohash = 1,
  max.call = 1000,
  verbose = TRUE,
  seed = 1
)

Arguments

hc

object of class 'concentration' obtained from 'highest_concentration()'

highest_geohash

the number of geohashes the searching algorithm is applied to. Defaults to 1 (i.e. algorithm is only applied to the geohash with the highest concentration).

max.call

maximum number of calls to the concentration function (i.e. the number of coordinates in the neighborhood of the highest concentration). Defaults to 1000.

verbose

show messages from the algorithm (TRUE/FALSE). Defaults to FALSE.

seed

set seed

Value

data.frame

Author(s)

Martin Haringa

Examples

## Not run: 
# Find highest concentration with a precision of a grid of 25 meters
hc1 <- highest_concentration(Groningen, amount, radius = 200,
 grid_distance = 25)

# Increase the number of calls for more extensive search
hc1_nghb <- neighborhood_gh_search(hc1, max.call = 7000, highest_geohash = 1)
hc2_nghb <- neighborhood_gh_search(hc1, max.call = 7000, highest_geohash = 2)
plot(hc1_nghb)
plot(hc2_nghb)

## End(Not run)