Spatial accessibility

Two-step floating catchment (2SFCA; Gaussian 2SFCA with G(d) = (exp(-d^2/(2 d0^2)) - exp(-1/2)) / (1 - exp(-1/2)) inside d0), Hansen (sum_j S_j exp(-beta d_ij)), the Joseph-Bantock gravity model with population competition, or distance to the nearest site.

Usage

SpatialAccessibility(
  population,
  supply,
  dist,
  method = c("2sfca", "g2sfca", "hansen", "gravity", "nearest"),
  d0 = NULL,
  beta = 1
)

Arguments

population

Demand per location.

supply

Capacity per site.

dist

Demand-by-site distance matrix.

method

"2sfca", "g2sfca", "hansen", "gravity" or "nearest".

d0

Catchment size.

beta

Decay parameter.

Value

list(accessibility, ratio, nearest, within).

References

Luo, W. and Wang, F. (2003). Measures of spatial accessibility to health care in a GIS environment. Environment and Planning B 30, 865-884. Dai, D. (2010). Health and Place 16, 1038-1052. Hansen, W. G. (1959). How accessibility shapes land use. Journal of the American Institute of Planners 25, 73-76.

Examples

SpatialAccessibility(c(100, 100), 10, matrix(c(1, 3)), d0 = 2)$accessibility
#> [1] 0.1 0.0