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Save a layout snapshot for a grouped sf dataset

Source: R/hierarchy.R
create_layout_snapshot.Rd

Captures the current drag offsets for a given grouping and returns a named list. Snapshots can be passed to inherit_layout() when switching to a finer grouping, or stored and later recovered with restore_layout_snapshot().

Usage

create_layout_snapshot(x, group, offsets = NULL)

Arguments

x

A data frame or sf object.

group

Column name (scalar character) defining the current grouping.

offsets

A data frame with region, dx_m, and dy_m columns, a CSV path to such a file, or NULL for an all-zero starting state.

Value

A named list with elements group (character), offsets (data frame or NULL), and timestamp (POSIXct).

See also

restore_layout_snapshot(), inherit_layout().

Examples

poly <- sf::st_sf(
  county = c("A", "B"),
  geometry = sf::st_sfc(
    sf::st_polygon(list(rbind(c(0,1e5),c(1e5,1e5),c(1e5,2e5),c(0,2e5),c(0,1e5)))),
    sf::st_polygon(list(rbind(c(0,0),c(1e5,0),c(1e5,1e5),c(0,1e5),c(0,0)))),
    crs = 3857
  )
)
offsets <- data.frame(region = c("A", "B"), dx_m = c(10000, -10000), dy_m = 0)
snap <- create_layout_snapshot(poly, group = "county", offsets = offsets)
snap$group
#> [1] "county"
snap$offsets
#>   region   dx_m dy_m
#> 1      A  10000    0
#> 2      B -10000    0