{ "name": "distance_to_vertex", "type": "function", "groups": ["GeometryGroup"], "description": "Returns the distance along the geometry to a specified vertex.", "arguments": [{ "arg": "geometry", "description": "a linestring geometry" }, { "arg": "vertex", "description": "vertex index, starting from 0; if the value is negative, the selected vertex index will be its total count minus the absolute value" }], "examples": [{ "expression": "distance_to_vertex(geometry:=geom_from_wkt('LineString(0 0, 10 0, 10 10)'),vertex:=1)", "returns": "10.0" }], "tags": ["distance", "specified", "vertex"] }