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Convert an sf, numeric, or other object to a POINT (sfg) or POINT, MULTIPOINT, LINESTRING, or MULTILINESTRING (sfc) object

Source: R/as_sf.R
as_point.Rd

Works with sf, sfc, and bbox objects using sf::st_centroid. Works with sf_bbox_point

Usage

as_point(..., to = "POINT")

as_points(..., to = "POINT")

as_startpoint(...)

as_endpoint(...)

as_line(..., to = "LINESTRING")

as_lines(..., to = "LINESTRING")

as_polygons(..., to = "POLYGON")

Arguments

...

See details.

to

The geometry type to return, either POINT or MULTIPOINT or LINESTRING or MULTILINESTRING.

Details

Using as_point:

For as_point, ... is passed to sf::st_centroid if ... is a sf, sfc, or bbox object, sf_bbox_point includes a bbox object and a string indicating the requested point position, or sf::st_point if ... includes a numeric vector.

Using as_points:

For as_points parameters are passed to as_point using purrr::map and then converted to sfc using sf::st_as_sfc. The ... parameters must include a crs, otherwise the crs will be NA for the resulting sfc object.

Using as_startpoint and as_endpoint:

as_startpoint and as_endpoint require a line parameter that is passed to lwgeom::st_startpoint or lwgeom::st_endpoint respectively. Both functions always return a sfc object matching the CRS of the input geometry.

Using as_lines:

If params do not have POINT or MULTIPOINT geometry, they are passed to as_points to convert to an sfc object. If the parameters have POINT geometry, they are combined to create a MULTIPOINT geometry.

For as_lines the ... parameters are passed to as_points and/or sf::st_cast.

Both as_line and as_lines do not consistently retain the coordinate reference system of the original object but this should be improved in the future.