{ "name": "extend", "type": "function", "description": "Extends the start and end of a linestring geometry by a specified amount. Lines are extended using the bearing of the first and last segment in the line. Distances are in the Spatial Reference System of this geometry.", "arguments": [ {"arg":"geometry","description":"a (multi)linestring geometry"}, {"arg":"start_distance","description":"distance to extend the start of the line"}, {"arg":"end_distance","description":"distance to extend the end of the line."}], "examples": [ { "expression":"geom_to_wkt(extend(geom_from_wkt('LineString(0 0, 1 0, 1 1)'),1,2))", "returns":"LineString (-1 0, 1 0, 1 3)"}] }