{
  "name": "angle_at_vertex",
  "type": "function",
  "groups": ["GeometryGroup"],
  "description": "Returns the bisector angle (average angle) to the geometry for a specified vertex on a linestring geometry. Angles are in degrees clockwise from north.",
  "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": "angle_at_vertex(geometry:=geom_from_wkt('LineString(0 0, 10 0, 10 10)'),vertex:=1)",
    "returns": "45.0"
  }],
  "tags": ["angles", "specified", "clockwise", "angle", "linestring", "degrees", "bisector", "north", "average", "vertex"]
}