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ES|QL ST_SIMPLIFY function

Embedded
geometry
Expression of type geo_point, geo_shape, cartesian_point or cartesian_shape. If null, the function returns null.
tolerance

Tolerance for the geometry simplification, in the units of the input SRS

Simplifies the input geometry by applying the Douglas-Peucker algorithm with a specified tolerance. Vertices that fall within the tolerance distance from the simplified shape are removed. Note that the resulting geometry may be invalid, even if the original input was valid.

geometry tolerance result
cartesian_point double cartesian_point
cartesian_shape double cartesian_shape
geo_point double geo_point
geo_shape double geo_shape 
ROW wkt = "POLYGON ((7.998 53.827, 9.470 53.068, 15.754 53.801, 16.523 57.160, 11.162 57.868, 8.064 57.445, 6.219 55.317, 7.998 53.827))"
| EVAL simplified = ST_SIMPLIFY(TO_GEOSHAPE(wkt), 0.7)
wkt:keyword simplified:geo_shape
POLYGON ((7.998 53.827, 9.470 53.068, 15.754 53.801, 16.523 57.160, 11.162 57.868, 8.064 57.445, 6.219 55.317, 7.998 53.827)) POLYGON ((9.47 53.068, 15.754 53.801, 16.523 57.16, 8.064 57.445, 6.219 55.317, 9.47 53.068))