wk (version 0.3.0)

wksxp: Mark lists as well-known "S" expressions

Description

Mark lists as well-known "S" expressions

Usage

wksxp(x = list())
parse_wksxp(x)
as_wksxp(x, ...)
# S3 method for default
as_wksxp(x, ...)
# S3 method for character
as_wksxp(x, ...)
# S3 method for wk_wksxp
as_wksxp(x, ..., include_z = NULL, include_m = NULL, include_srid = NULL)
# S3 method for wk_wkt
as_wksxp(x, ..., include_z = NULL, include_m = NULL, include_srid = NULL)
# S3 method for wk_wkb
as_wksxp(x, ..., include_z = NULL, include_m = NULL, include_srid = NULL)

Arguments

x

A list() features (see details)

...

Unused

include_z

Include the values of the Z and M coordinates and/or SRID in the output? Use FALSE to omit, TRUE to include, or NA to include only if present. Note that using TRUE may result in an error if there is no value present in the original.

include_m

Include the values of the Z and M coordinates and/or SRID in the output? Use FALSE to omit, TRUE to include, or NA to include only if present. Note that using TRUE may result in an error if there is no value present in the original.

include_srid

Include the values of the Z and M coordinates and/or SRID in the output? Use FALSE to omit, TRUE to include, or NA to include only if present. Note that using TRUE may result in an error if there is no value present in the original.

Value

A new_wk_wksxp()

Details

The "wksxp" format is experimental, but was written as a way to make it possible for packages to generate wkb() vectors without needing to use C++. The format represents geometries as following:

• points are matrices with zero or one row

• linestrings are matrices (one row per point)

• polygons are lists of matrices (one matrix per ring)

• multi (point, linestring, polygon) types are lists of the simple types (without any meta information)

• collections are lists of any type (must contain meta)

Any geometry that isn't in a multi type must have meta information encoded as attributes. The attribures that are used are:

• class: "wk_(point|linestring|...)

• has_z: use TRUE if there is a Z coordinate (may be omitted if false)

• has_m: use TRUE if there is an M coordinate (may be omitted if false)

This is similar to the sf::st_sfc() format, but the formats aren't interchangable.

Examples

# NOT RUN {
wksxp(wkt_translate_wksxp("POINT (20 10)"))

# }