Turn a spatial object into a frame — as

Converts an sf object (points or polygons) into the plain data frame that travel_matrix() and select_units() expect: a column unit, the coordinates lat/lon (centroids for polygons, in WGS 84) and, for polygons, their area in square kilometres, next to the other columns of the object. Nothing spatial is kept: use as_sf() to put the results back on the geometries.

Usage

as_frame(x, unit = NULL)

Arguments

x: An sf object (the sf package must be installed), or a data frame returned unchanged.
unit: Name of the column with the unit names; made from the row numbers when NULL and no unit column exists.

Value

A tibble with unit, lat, lon, area (polygons only) and the attribute columns.

Examples

if (requireNamespace("sf", quietly = TRUE)) {
  sq <- sf::st_sfc(sf::st_polygon(list(rbind(c(0, 0), c(0, 1), c(1, 1), c(1, 0), c(0, 0)))),
    crs = 4326
  )
  cells <- sf::st_sf(crop = 3, geometry = sf::st_make_grid(sq, n = 3))
  as_frame(cells)
}
#> # A tibble: 9 × 5
#>   unit    lat   lon  area  crop
#>   <chr> <dbl> <dbl> <dbl> <dbl>
#> 1 u1    0.167 0.167 1374.     3
#> 2 u2    0.167 0.500 1374.     3
#> 3 u3    0.167 0.833 1374.     3
#> 4 u4    0.500 0.167 1374.     3
#> 5 u5    0.500 0.500 1374.     3
#> 6 u6    0.500 0.833 1374.     3
#> 7 u7    0.833 0.167 1374.     3
#> 8 u8    0.833 0.500 1374.     3
#> 9 u9    0.833 0.833 1374.     3