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{
"name": "smooth",
"type": "function",
2020-07-02 01:46:48 +01:00
"groups": ["GeometryGroup"],
"description":"Smooths a geometry by adding extra nodes which round off corners in the geometry. If input geometries contain Z or M values, these will also be smoothed and the output geometry will retain the same dimensionality as the input geometry.",
"arguments": [ {"arg":"geometry","description":"a geometry"},
{"arg":"iterations", "optional":true, "default":"1", "description":"number of smoothing iterations to apply. Larger numbers result in smoother but more complex geometries."},
{"arg":"offset", "optional":true, "default":"0.25", "description":"value between 0 and 0.5 which controls how tightly the smoothed geometry follow the original geometry. Smaller values result in a tighter smoothing, larger values result in looser smoothing."},
{"arg":"min_length", "optional":true, "default":"-1", "description":"minimum length of segments to apply smoothing to. This parameter can be used to avoid placing excessive additional nodes in shorter segments of the geometry."},
{"arg":"max_angle", "optional":true, "default":"180", "description":"maximum angle at node for smoothing to be applied (0-180). By lowering the maximum angle intentionally sharp corners in the geometry can be preserved. For instance, a value of 80 degrees will retain right angles in the geometry."} ],
"examples": [ { "expression":"geom_to_wkt(smooth(geometry:=geom_from_wkt('LineString(0 0, 5 0, 5 5)'),iterations:=1,offset:=0.2,min_length:=-1,max_angle:=180))", "returns":"'LineString (0 0, 4 0, 5 1, 5 5)'"}]
}