wk_meta {wk} | R Documentation |
Extract feature-level meta
Description
These functions return the non-coordinate information of a geometry and/or vector. They do not parse an entire geometry/vector and are intended to be very fast even for large vectors.
Usage
wk_meta(handleable, ...)
## Default S3 method:
wk_meta(handleable, ...)
wk_vector_meta(handleable, ...)
## Default S3 method:
wk_vector_meta(handleable, ...)
wk_meta_handler()
wk_vector_meta_handler()
wk_geometry_type_label(geometry_type)
wk_geometry_type(geometry_type_label)
Arguments
handleable |
A geometry vector (e.g., |
... |
Passed to the |
geometry_type |
An integer code for the geometry type. These integers follow the WKB specification (e.g., 1 for point, 7 for geometrycollection). |
geometry_type_label |
A character vector of (lowercase) geometry type labels as would be found in WKT (e.g., point, geometrycollection). |
Value
A data.frame with columns:
-
geometry_type
: An integer identifying the geometry type. A value of 0 indicates that the types of geometry in the vector are not known without parsing the entire vector. -
size
: For points and linestrings, the number of coordinates; for polygons, the number of rings; for collections, the number of child geometries. A value of zero indicates an EMPTY geometry. A value ofNA
means this value is unknown without parsing the entire geometry. -
has_z
:TRUE
if coordinates contain a Z value. A value ofNA
means this value is unknown without parsing the entire vector. -
has_m
:TRUE
if coordinates contain an M value. A value ofNA
means this value is unknown without parsing the entire vector. -
srid
: An integer identifying a CRS or NA if this value was not provided. -
precision
: A grid size or 0.0 if a grid size was not provided. Note that coordinate values may not have been rounded; the grid size only refers to the level of detail with which they should be interpreted. -
is_empty
:TRUE
if there is at least one non-empty coordinate. For the purposes of this value, a non-empty coordinate is one that contains at least one value that is notNA
orNaN
.
Examples
wk_vector_meta(as_wkt("LINESTRING (0 0, 1 1)"))
wk_meta(as_wkt("LINESTRING (0 0, 1 1)"))
wk_meta(as_wkb("LINESTRING (0 0, 1 1)"))
wk_geometry_type_label(1:7)
wk_geometry_type(c("point", "geometrycollection"))