Build a Geoscale from parent-child crosswalks

Assembles a wide leaves table from a set of two-column crosswalks. Each crosswalk is a data.frame whose column names are two level names; the builder joins them together, starting from the finest level, until every level in levels is present.

Usage

geoscale_build(..., levels, weights = NULL, name = "", desc = "")

Arguments

...

Additional arguments passed to geoscale_from_leaves().

levels

Ordered character vector of level names, coarsest first. The last entry is the atom level.

weights

Optional data.frame keyed by the atom level, carrying one or more numeric weight columns.

name, desc

Short name and description.

Value

A Geoscale.

Details

Crosswalks need not form a strict chain: a level that cross-cuts the others (a grid zone crossing state lines, say) is expressed simply by giving its crosswalk against the finest level.

Examples

geoscale_build(
  data.frame(country = c("N", "N", "S"),
             state   = c("N1", "N2", "S1")),
  data.frame(state = c("N1", "N1", "N2", "S1"),
             atom  = c("A1", "A2", "A3", "A4")),
  levels  = c("country", "state", "atom"),
  weights = data.frame(atom = c("A1", "A2", "A3", "A4"),
                       km2  = c(10, 20, 30, 40))
)
#> Geoscale: <unnamed> 
#> Levels (3, coarsest first):
#>   - country (2)
#>     - state (3)
#>       - atom (4)
#> Atoms: 4
#> Weights: km2 (default: km2)