Compute diversities for a collection of spatial interaction models

The function computes for each spatial interaction model of its sim_list parameter the diversity() of the corresponding destination flows and returns the values as a vector. The type of diversity and the associated parameters are identical for all models.

Usage

grid_diversity(
  sim,
  definition = c("shannon", "renyi", "ND", "RW"),
  order = 1L,
  activity = c("destination", "attractiveness"),
  ...
)

Arguments

sim: a collection of spatial interaction models, an object of class sim_list
definition: diversity definition "shannon" (default), "renyi" (see details) or a definition supported by terminals()
order: order of the Rényi entropy, used only when definition="renyi"
activity: specifies whether the diversity is computed based on the destination flows (for activity="destination", the default case) or on the attractivenesses (for activity="attractiveness").
...: additional parameters

Value

a vector of diversities, one per spatial interaction model

Details

See diversity() for the definition of the diversities. Notice that diversity() is generic and can be applied directly to sim_list objects. The current function is provided to be explicit in R code about what is a unique model and what is a collection of models (using function names that start with "grid_")

Examples

distances <- french_cities_distances[1:15, 1:15] / 1000 ## convert to km
production <- log(french_cities$population[1:15])
attractiveness <- log(french_cities$area[1:15])
all_flows <- grid_blvim(
  distances, production, c(1.1, 1.25, 1.5),
  c(1, 2, 3, 4) / 500, attractiveness,
  epsilon = 0.1,
  bipartite = FALSE
)
diversities <- grid_diversity(all_flows)
diversities ## should be a length 12 vector
#>  [1] 1.891319 1.000000 1.000000 1.976166 1.968974 1.945845 5.027994 2.410876
#>  [9] 1.981744 6.907061 5.460118 2.458216
grid_diversity(all_flows, "renyi", 3)
#>  [1] 1.734908 1.000000 1.000000 1.931990 1.912744 1.854403 3.636500 2.165508
#>  [9] 1.947308 4.905153 4.077701 2.212184