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This function allows to efficiently calculate elevation statistics for polygons. For each polygon, the desired statistic/s (mean, median or sd) is/are returned. The required resources for this indicator are:

Format

A tibble with a column for elevation statistics (in meters)

Details

The following arguments can be set:

stats_elevation

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

engine

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

Examples

if (Sys.getenv("NOT_CRAN") == "true") {
  library(sf)
  library(mapme.biodiversity)

  temp_loc <- file.path(tempdir(), "mapme.biodiversity")
  if (!file.exists(temp_loc)) {
    dir.create(temp_loc)
    resource_dir <- system.file("res", package = "mapme.biodiversity")
    file.copy(resource_dir, temp_loc, recursive = TRUE)
  }

  (try(aoi <- system.file("extdata", "sierra_de_neiba_478140_2.gpkg",
    package = "mapme.biodiversity"
  ) %>%
    read_sf() %>%
    init_portfolio(
      years = 2000:2020,
      outdir = file.path(temp_loc, "res"),
      tmpdir = tempdir(),
      add_resources = FALSE,
      verbose = FALSE
    ) %>%
    get_resources("nasa_srtm") %>%
    calc_indicators("elevation",
      stats_elevation = c("mean", "median", "sd", "var"), engine = "extract"
    ) %>%
    tidyr::unnest(elevation)))
}
#> Error in map(.x, .f, ...) :  In index: 4.
#> Caused by error:
#> ! [extract] not a valid function
#> Warning: Error occured at polygon 1 with the following error message: Error in map(.x, .f, ...) :  In index: 4.
#> Caused by error:
#> ! [extract] not a valid function
#> . 
#>  Returning NAs.
#> Simple feature collection with 1 feature and 6 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: 1 × 7
#>   WDPAID NAME            DESIG_ENG ISO3  assetid value                      geom
#>    <dbl> <chr>           <chr>     <chr>   <int> <lgl>             <POLYGON [°]>
#> 1 478140 Sierra de Neiba National… DOM         1 NA    ((-71.76134 18.66333, -7…