Linear referencing

Source: R/geos-binary-atomic.R, R/geos-unary-geometry.R

  • geos_project() and geos_project_normalized() return the distance of point geom2 projected on geom1 from the origin of geom1, which must be a lineal geometry.

  • geos_interpolate() performs an inverse operation, returning the point along geom representing the given distance from the origin along the geometry.

  • _normalized() variants use a distance normalized to the geos_length() of the geometry.

geos_project(geom1, geom2)

geos_project_normalized(geom1, geom2)

geos_interpolate(geom, distance)

geos_interpolate_normalized(geom, distance_normalized)

Arguments

geom1, geom2

GEOS geometry vectors, recycled to a common length.

geom

A GEOS geometry vector

distance

Distance along the linestring to interpolate

distance_normalized

Distance along the linestring to interpolate relative to the length of the linestring.

Examples

geos_interpolate("LINESTRING (0 0, 1 1)", 1)
#> <geos_geometry[1]>
#> [1] <POINT (0.70711 0.70711)>
geos_interpolate_normalized("LINESTRING (0 0, 1 1)", 1)
#> <geos_geometry[1]>
#> [1] <POINT (1 1)>

geos_project("LINESTRING (0 0, 10 10)", "POINT (5 5)")
#> [1] 7.071068
geos_project_normalized("LINESTRING (0 0, 10 10)", "POINT (5 5)")
#> [1] 0.5