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Categorize polygon by Province/State

Source: R/helpers.R
assign_prov_state.Rd

Categorizes custom stratification polygons by province or state if possible. This can be useful for calculating regional indices (generate_indices()) or trends (generate_trends()) on a custom stratification, or if you want to create a geofaceted plot (plot_geofacet()).

Usage

assign_prov_state(
  strata_map,
  min_overlap = 0.75,
  plot = FALSE,
  keep_spatial = TRUE
)

Arguments

strata_map

sf data frame. Strata polygons to be categorized.

min_overlap

Numeric. The minimum proportion of overlap between a stratum polygon and a Province or State. Overlap below this proportion will raise warnings.

plot

Logical. Whether to plot how polygons were assigned to Provinces or States

keep_spatial

Logical. Whether the output should be a spatial data frame or not.

Value

(Spatial) data frame with strata assigned to Province/State.

See also

Other helper functions: load_map(), search_species()

Examples

# Demonstration of why we can't divide BCR by Provinces and States!
map <- load_map("bcr")
assign_prov_state(map, plot = TRUE)
#> Warning: 28 strata are assigned to a province or state based on less than the minimum specified overlap

#> Simple feature collection with 223 features and 7 fields
#> Geometry type: GEOMETRY
#> Dimension:     XY
#> Bounding box:  xmin: -4748423 ymin: -1638890 xmax: 2988370 ymax: 4517253
#> Projected CRS: North_America_Albers_Equal_Area_Conic
#> # A tibble: 223 × 8
#>    strata_name prov_state country                  country_code province_state  
#>  * <chr>       <chr>      <chr>                    <chr>        <chr>           
#>  1 BCR10       BC         United States of America US           Washington      
#>  2 BCR5        BC         United States of America US           Washington      
#>  3 BCR9        NV         United States of America US           Washington      
#>  4 BCR10       BC         Canada                   CA           British Columbia
#>  5 BCR4        AK         Canada                   CA           British Columbia
#>  6 BCR5        BC         Canada                   CA           British Columbia
#>  7 BCR6        NT         Canada                   CA           British Columbia
#>  8 BCR9        NV         Canada                   CA           British Columbia
#>  9 BCR10       BC         United States of America US           Idaho           
#> 10 BCR16       CO         United States of America US           Idaho           
#> # ℹ 213 more rows
#> # ℹ 3 more variables: geom <GEOMETRY [m]>, p_area <dbl>, note <chr>

# Use custom stratification, using sf map object
# e.g. with WBPHS stratum boundaries 2019
# available: https://ecos.fws.gov/ServCat/Reference/Profile/142628

if (FALSE) {
map <- sf::read_sf("../WBPHS_Stratum_Boundaries_2019") %>%
  rename(strata_name = STRAT) # expects this column
s <- assign_prov_state(map, plot = TRUE)
# Some don't divide nicely, we could try a different min_overlap

s <- assign_prov_state(map, min_overlap = 0.6, plot = TRUE)
}