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.
wk_meta(handleable, ...)
# S3 method for default
wk_meta(handleable, ...)
wk_vector_meta(handleable, ...)
# S3 method for default
wk_vector_meta(handleable, ...)
wk_meta_handler()
wk_vector_meta_handler()
wk_geometry_type_label(geometry_type)
wk_geometry_type(geometry_type_label)A geometry vector (e.g., wkb(), wkt(), xy(),
rct(), or sf::st_sfc()) for which wk_handle() is defined.
Passed to the wk_handle() method.
An integer code for the geometry type. These integers follow the WKB specification (e.g., 1 for point, 7 for geometrycollection).
A character vector of (lowercase) geometry type labels as would be found in WKT (e.g., point, geometrycollection).
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 of NA means this value is unknown without parsing the
entire geometry.
has_z: TRUE if coordinates contain a Z value. A value of NA
means this value is unknown without parsing the entire vector.
has_m: TRUE if coordinates contain an M value. A value of NA
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 not NA or NaN.
wk_vector_meta(as_wkt("LINESTRING (0 0, 1 1)"))
#> geometry_type size has_z has_m
#> 1 0 1 NA NA
wk_meta(as_wkt("LINESTRING (0 0, 1 1)"))
#> geometry_type size has_z has_m srid precision is_empty
#> 1 2 NA FALSE FALSE NA 0 FALSE
wk_meta(as_wkb("LINESTRING (0 0, 1 1)"))
#> geometry_type size has_z has_m srid precision is_empty
#> 1 2 2 FALSE FALSE NA 0 FALSE
wk_geometry_type_label(1:7)
#> [1] "point" "linestring" "polygon"
#> [4] "multipoint" "multilinestring" "multipolygon"
#> [7] "geometrycollection"
wk_geometry_type(c("point", "geometrycollection"))
#> [1] 1 7