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Reto Joerg [ctb]| Title: | Floating Catchment Area (FCA) Methods to Calculate Spatial Accessibility |
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| Description: | Perform various floating catchment area methods to calculate a spatial accessibility index (SPAI) for demand point data. The distance matrix used for weighting is normalized in a preprocessing step using common functions (gaussian, gravity, exponential or logistic). |
| Authors: | Etienne Grueebler [aut, cre],
Merlin Unterfinger [aut] ,
Reto Joerg [ctb] |
| Maintainer: | Etienne Grueebler <[email protected]> |
| License: | GPL (>= 3) |
| Version: | 0.1.0 |
| Built: | 2025-02-13 03:56:57 UTC |
| Source: | https://github.com/egrueebler/fca |
Distance weight methods
dist_normalize(D, d_max, imp_function, function_d_max = 0.01)dist_normalize(D, d_max, imp_function, function_d_max = 0.01)
D |
numeric matrix, distance or time values |
d_max |
numeric, threshold for max distance |
imp_function |
character, type of distance weights method |
function_d_max |
numeric, condition for the result of the function(d_max) used to calculate beta (default = 0.01, is considered optimal for the Gaussian function) |
matrix, normalized distance or time values
dist_normalize(matrix(10), 10, "gaussian")dist_normalize(matrix(10), 10, "gaussian")
Two-Step Floating Catchment Area method
spai_2sfca(p, s, W, step = 2)spai_2sfca(p, s, W, step = 2)
p |
numeric vector, number of population at origin locations |
s |
numeric vector, capacity of services at supply locations |
W |
numeric matrix, distance or time matrix |
step |
numeric, number of the steps of the method to perform |
data.frame, depending on selected step
p <- 1:4 s <- 1:6 W <- matrix(1:24, ncol = 4, nrow = 6) spai <- spai_2sfca(p, s, W, step = 2)p <- 1:4 s <- 1:6 W <- matrix(1:24, ncol = 4, nrow = 6) spai <- spai_2sfca(p, s, W, step = 2)
Three-Step Floating Catchment Area method
spai_3sfca(p, s, W, step = 3)spai_3sfca(p, s, W, step = 3)
p |
numeric vector, number of population at origin locations |
s |
numeric vector, capacity of services at supply locations |
W |
numeric matrix, distance or time matrix |
step |
numeric, number of the steps of the method to perform |
data.frame, depending on selected step
p <- 1:4 s <- 1:6 W <- matrix(1:24, ncol = 4, nrow = 6) spai <- spai_3sfca(p, s, W, step = 3)p <- 1:4 s <- 1:6 W <- matrix(1:24, ncol = 4, nrow = 6) spai <- spai_3sfca(p, s, W, step = 3)
Modified-Huff-Three-Step Floating Catchment Area method
spai_mh3sfca(p, s, W, step = 3)spai_mh3sfca(p, s, W, step = 3)
p |
numeric vector, number of population at origin locations |
s |
numeric vector, capacity of services at supply locations |
W |
numeric matrix, distance or time matrix |
step |
numeric, number of the steps of the method to perform |
data.frame, depending on selected step
p <- 1:4 s <- 1:6 W <- matrix(1:24, ncol = 4, nrow = 6) spai <- spai_mh3sfca(p, s, W, step = 3)p <- 1:4 s <- 1:6 W <- matrix(1:24, ncol = 4, nrow = 6) spai <- spai_mh3sfca(p, s, W, step = 3)