Points2sequence
Geometric functions points2sequence
- points2sequence(point)
- points2sequence(point, Sequence_rel)
- points2sequence(point, Sequence_rel, ordinal)
- points2sequence_p(point)
- points2sequence_ps(point, Sequence_rel)
- points2sequence_pso(point, Sequence_rel, ordinal)
- points2sequence_po(point, ordinal)
- points2arc(point)
- points2arc(point, Sequence_rel)
- points2arc(point, Sequence_rel, ordinal)
- points2arc_p(point)
- points2arc_ps(point, Sequence_rel)
- points2arc_pso(point, Sequence_rel, ordinal)
- points2arc_po(point, ordinal)
- points2polygon(point)
- points2polygon(point, Sequence_rel)
- points2polygon(point, Sequence_rel, ordinal)
- points2polygon_p(point)
- points2polygon_ps(point, Sequence_rel)
- points2polygon_pso(point, Sequence_rel, ordinal)
- points2polygon_po(point, ordinal)
- points2multi_point(point)
- points2multi_point(point, Sequence_rel)
- points2multi_point(point, Sequence_rel, ordinal)
- points2multi_point_p(point)
- points2multi_point_ps(point, Sequence_rel)
- points2multi_point_pso(point, Sequence_rel, ordinal)
- points2multi_point_po(point, ordinal)
- points2sequence(point, Sequence_rel, ordinal) and its variants result in a point attribute with composition type arc.
- points2arc(point, Sequence_rel, ordinal) and its variants are a feature-type-named alias of points2sequence; they also result in a point attribute with composition type arc.
- points2polygon(point, Sequence_rel, ordinal) and its variants result in a point attribute with composition type polygon.
- points2multi_point(point, Sequence_rel, ordinal) and its variants result in a point attribute with composition type multipoint.
All four function groups are used to make arcs, polygons or multipoints, based on a data item with points, a relation from the point towards the domain unit of the resulting geometries and a data item indicating the order of the points in the resulting geometries. They differ only in the composition type of the result.
The _ps and _po suffixes disambiguate a two-argument call: _ps reads the second argument as Sequence_rel, _po reads it as ordinal. The base (unsuffixed) group accepts one, two or three arguments, and reads a second argument as Sequence_rel.
They all have the following arguments:
- point = a data item with the points for the resulting arcs/polygons.
- Sequence_rel = an optional relation towards the domain unit of the resulting arcs/polygons. If no Sequence_rel is configured, the resulting data item with arc/polygons is a parameter.
- ordinal = an optional data item with the order of each point in the resulting arcs/polygons. If no ordinal is specified, the configuration order is used.
- data item point with a point value type
- data item Sequence_rel with as values unit the domain unit of the resulting arcs/polygons.
- data item ordinal with uint32 value type
The domain units of all arguments must match.
5.15; variants available since 7.033
points2arc and points2multi_point (and their _p / _ps / _po / _pso variants) are available since 20.2.0.
O(n log n) if ordinal sorting is needed, otherwise O(n) where n = number of points. Groups points by Sequence_rel and orders within groups.
attribute<fpoint> geometry (road, arc) := points2sequence(point, Sequence_rel, ordinal);
The same point table can be turned into a polygon or multipoint result by choosing the matching function and composition type:
attribute<fpoint> area_geometry (road, polygon) := points2polygon(point, Sequence_rel, ordinal);
attribute<fpoint> point_geometry (road, multipoint) := points2multi_point(point, Sequence_rel, ordinal);
| point | Sequence_rel | Ordinal |
|---|---|---|
| {399246, 112631} | 0 | 0 |
| {398599, 111866} | 0 | 1 |
| {398599, 111866} | 1 | 0 |
| {399495, 111924} | 1 | 1 |
| {401801, 111524} | 1 | 2 |
| {401529, 114921} | 2 | 0 |
| {398584, 114823} | 2 | 1 |
domain RoadPointSet, nr of rows = 7
| geometry |
|---|
| {2 {399246, 112631}{398599, 111866}} |
| {3 {398599, 111866}{399495, 111924} {401801,111524}} |
| {2 {401529, 114921}{398584, 114823}} |
domain Road, nr of rows = 3
- sequence2points
- bg_buffer_multi_point - buffers each coordinate of a multipoint geometry