Calculate accessibility statistics

Accessibility is the ease with which larger cities can be reached from a certain location. This function allows to efficiently calculate accessibility statistics (i.e. travel time to nearby major cities) for polygons. For each polygon, the desired statistic/s (mean, median or sd) is/are returned.

Usage

calc_traveltime(engine = "extract", stats = "mean")

Arguments

engine

The preferred processing functions from either one of "zonal", "extract" or "exactextract" as character.

stats

Function to be applied to compute statistics for polygons either single or multiple inputs as character. Supported statistics are: "mean", "median", "sd", "min", "max", "sum" "var".

Value

A function that returns an indicator tibble with city ranges and statisics as variable and corresponding values (in minutes) as value.

Details

The required resources for this indicator are:

• nelson_et_al

Examples

# \dontrun{
library(sf)
library(mapme.biodiversity)

outdir <- file.path(tempdir(), "mapme-data")
dir.create(outdir, showWarnings = FALSE)

mapme_options(
  outdir = outdir,
  verbose = FALSE
)

aoi <- system.file("extdata", "sierra_de_neiba_478140_2.gpkg",
  package = "mapme.biodiversity"
) %>%
  read_sf() %>%
  get_resources(get_nelson_et_al(ranges = "100k_200k")) %>%
  calc_indicators(
    calc_traveltime(engine = "extract", stats = c("min", "max"))
  ) %>%
  portfolio_long()

aoi
#> Simple feature collection with 2 features and 8 fields
#> Geometry type: POLYGON
#> Dimension:     XY
#> Bounding box:  xmin: -71.80933 ymin: 18.57668 xmax: -71.33201 ymax: 18.69931
#> Geodetic CRS:  WGS 84
#> # A tibble: 2 × 9
#>   WDPAID ISO3  assetid indicator  datetime            variable       unit  value
#>    <dbl> <chr>   <int> <chr>      <dttm>              <chr>          <chr> <dbl>
#> 1 478140 DOM         1 traveltime 2015-01-01 00:00:00 100k_200k_tra… minu…   162
#> 2 478140 DOM         1 traveltime 2015-01-01 00:00:00 100k_200k_tra… minu…   528
#> # ℹ 1 more variable: geom <POLYGON [°]>
# }