geofacet (version 0.1.9)

grid_auto: Generate a grid automatically from a country/continent name or a SpatialPolygonsDataFrame

Description

Generate a grid automatically from a country/continent name or a SpatialPolygonsDataFrame

Usage

grid_auto(x, names = NULL, codes = NULL, seed = NULL)

Arguments

x

A country/continent name or a SpatialPolygonsDataFrame to build a grid for.

names

An optional vector of variable names in x@data to use as "name_" columns in the resulting grid.

codes

An optional vector of variable names in x@data to use as "code_" columns in the resulting grid.

seed

An optional random seed sent to calculate_grid.

Details

If a country or continent name is specified for x, it can be any of the strings found in auto_countries or auto_states. In this case, the rnaturalearth package will be searched for the corresponding shapefiles. You can use get_ne_data to see what these shapefiles look like.

The columns of the @data component of resulting shapefile (either user-specified or fetched from rnaturalearth) are those that will be available to names and codes.

Examples

# NOT RUN {
# auto grid using a name to identify the country
grd <- grid_auto("brazil", seed = 1234)
grid_preview(grd, label = "name")
# open the result up in the grid designer for further refinement
grid_design(grd, label = "name")

# using a custom file (can be GeoJSON or shapefile)
ff <- system.file("extdata", "bay_counties.geojson", package = "geogrid")
bay_shp <- geogrid::read_polygons(ff)
grd <- grid_auto(bay_shp, seed = 1) # names are inferred
grid_preview(grd, label = "name_county")
grid_design(grd, label = "code_fipsstco")

# explicitly specify the names and codes variables to use
grd <- grid_auto(bay_shp, seed = 1, names = "county", codes = "fipsstco")
grid_preview(grd, label = "name_county")
grid_preview(grd, label = "code_fipsstco")
# }