Clean up and extend expression geometry functions:
- New expression functions for area(geom), perimeter(geom),
point_n(geom), start_point(geom), end_point(geom), make_point(x,y)
- Add new variant to length() function which takes a geometry object,
allows for length(geom) evaluation.
- Rename x_at, y_at to $x_at, $y_at (alias old names) to reflect that
these only work on current feature geometry
- Add x(geom), y(geom) functions which return x and y coordinate
for point geometries or centroid x/y for non-point geometries
(fix #11008)
2015-09-18 05:41:38 +10:00
{
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"name": "point_n",
"type": "function",
2020-07-02 01:46:48 +01:00
"groups": ["GeometryGroup"],
Clean up and extend expression geometry functions:
- New expression functions for area(geom), perimeter(geom),
point_n(geom), start_point(geom), end_point(geom), make_point(x,y)
- Add new variant to length() function which takes a geometry object,
allows for length(geom) evaluation.
- Rename x_at, y_at to $x_at, $y_at (alias old names) to reflect that
these only work on current feature geometry
- Add x(geom), y(geom) functions which return x and y coordinate
for point geometries or centroid x/y for non-point geometries
(fix #11008)
2015-09-18 05:41:38 +10:00
"description": "Returns a specific node from a geometry.",
"arguments": [ {"arg":"geometry","description":"geometry object"},
2019-03-12 16:24:04 +07:00
{"arg":"index","description":"index of node to return, where 1 is the first node; if the value is negative, the selected vertex index will be its total count minus the absolute value"} ],
Clean up and extend expression geometry functions:
- New expression functions for area(geom), perimeter(geom),
point_n(geom), start_point(geom), end_point(geom), make_point(x,y)
- Add new variant to length() function which takes a geometry object,
allows for length(geom) evaluation.
- Rename x_at, y_at to $x_at, $y_at (alias old names) to reflect that
these only work on current feature geometry
- Add x(geom), y(geom) functions which return x and y coordinate
for point geometries or centroid x/y for non-point geometries
(fix #11008)
2015-09-18 05:41:38 +10:00
"examples": [ { "expression":"geom_to_wkt(point_n(geom_from_wkt('POLYGON((0 0, 4 0, 4 2, 0 2, 0 0))'),2))", "returns":"'Point (4 0)'"}]
}
