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Import/export shapefiles.

Source: R/utils_shapefile.R
utils_shapefile.Rd

  • shapefile_input() creates or imports a shapefile and optionally converts it to an sf object. It can also cast POLYGON or MULTIPOLYGON geometries to MULTILINESTRING if required.

  • shapefile_export() exports an object (sf or SpatVector) to a file.

  • shapefile_view() is a simple wrapper around mapview() to plot a shapefile.

Usage

shapefile_input(
  shapefile,
  info = TRUE,
  as_sf = TRUE,
  multilinestring = FALSE,
  ...
)

shapefile_export(shapefile, filename, ...)

shapefile_view(
  shapefile,
  attribute = NULL,
  type = c("shape", "centroid"),
  color_regions = custom_palette(c("red", "yellow", "forestgreen")),
  ...
)

Arguments

shapefile

For shapefile_input(), character (filename), or an object that can be coerced to a SpatVector, such as an sf (simple features) object. See terra::vect() for more details.

For shapefile_export(), a SpatVector or an sf object to be exported as a shapefile.

info

Logical value indicating whether to print information about the imported shapefile (default is TRUE).

as_sf

Logical value indicating whether to convert the imported shapefile to an sf object (default is TRUE).

multilinestring

Logical value indicating whether to cast polygon geometries to MULTILINESTRING geometries (default is FALSE).

...

Additional arguments to be passed to terra::vect() (shapefile_input()), terra::writeVector() (shapefile_export()) or mapview::mapview() (shapefile_view()).

filename

The path to the output shapefile.

attribute

The attribute to be shown in the color key. It must be a variable present in shapefile.

type

A character string specifying whether to visualize the shapefile as "shape" or as "centroid". Partial matching is allowed. If set to "centroid", the function will convert the shapefile's geometry to centroids before displaying. Defaults to "shape".

color_regions

The color palette to represent attribute.

Value

  • shapefile_input() returns an object of class sf (default) representing the imported shapefile.

  • shapefile_export() returns a NULL object.

  • shapefile_view() returns an object of class mapview.

Examples

library(pliman)
shp <- system.file("ex/lux.shp", package="terra")
shp_file <- shapefile_input(shp, as_sf = FALSE)
#>  class       : SpatVector 
#>  geometry    : polygons 
#>  dimensions  : 12, 6  (geometries, attributes)
#>  extent      : 5.74414, 6.528252, 49.44781, 50.18162  (xmin, xmax, ymin, ymax)
#>  source      : lux.shp
#>  coord. ref. : lon/lat WGS 84 (EPSG:4326) 
#>  names       :  ID_1   NAME_1  ID_2   NAME_2  AREA   POP
#>  type        : <num>    <chr> <num>    <chr> <num> <int>
#>  values      :     1 Diekirch     1 Clervaux   312 18081
#>                    1 Diekirch     2 Diekirch   218 32543
#>                    1 Diekirch     3  Redange   259 18664
shapefile_view(shp_file)