Pooja444 commented on code in PR #621: URL: https://github.com/apache/incubator-sedona/pull/621#discussion_r857042504
########## docs/api/flink/Function.md: ########## @@ -152,6 +152,55 @@ Input: `POLYGON ((-0.5 -0.5, -0.5 0.5, 0.5 0.5, 0.5 -0.5, -0.5 -0.5))` Output: `POLYGON ((-0.5 -0.5, 0.5 -0.5, 0.5 0.5, -0.5 0.5, -0.5 -0.5))` +## ST_PointN + +Introduction: Return the Nth point in a single linestring or circular linestring in the geometry. Negative values are counted backwards from the end of the LineString, so that -1 is the last point. Returns NULL if there is no linestring in the geometry. + +Format: `ST_PointN(A:geometry, B:integer)` + +Since: `v1.2.1` + +Examples: + +```SQL +SELECT ST_PointN(df.geometry, 2) +FROM df +``` + +Input: `LINESTRING(0 0, 1 2, 2 4, 3 6), 2` + +Output: `POINT (1 2)` + +Input: `LINESTRING(0 0, 1 2, 2 4, 3 6), -2` + +Output: `POINT (2 4)` + +Input: `CIRCULARSTRING(1 1, 1 2, 2 4, 3 6, 1 2, 1 1), -1` + +Output: `POINT (1 1)` + + +## ST_ExteriorRing + +Introduction: Returns a LINESTRING representing the exterior ring (shell) of a POLYGON. Returns NULL if the geometry is not a polygon. + +Format: `ST_ExteriorRing(A:geometry)` + +Since: `v1.2.1` + +Examples: + +```SQL +SELECT ST_ExteriorRing(df.geometry) +FROM df +``` + +Input: `POLYGON((0 0, 1 1, 2 1, 0 1, 1 -1))` Review Comment: Updated it -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
