ST_MAKEELLIPSE Documentation

[scoddou]

Describe the bug
@vdelacruzb in relation to pull #477

I think the angle argument in ST_MAKEELLIPSE might be positive clockwise, relative y-axis north. I decomposed a "4" point ellipse
(really 5 points) in the example below to check how points were constructed by turf.

Example: when degree is 0, point 1 indexed from 0 is oriented north (aka y-axis relative north, or x-axis relative east). And when degree is 90, point 1 indexed from 0 is oriented east. Not quite sure how to "define" this in the doc's though...

But let me know if I misunderstand the behavior

To Reproduce

WITH

DATA AS (
SELECT '5 DEG' AS TYPE, TO_ARRAY(ST_ASGEOJSON(CARTO.CARTO.ST_MAKEELLIPSE(ST_POINT(-70,40), 2, 10, 5, 'kilometers', 4)):coordinates[0]) AS POINT_ARR
UNION ALL
SELECT '45 DEG' AS TYPE, TO_ARRAY(ST_ASGEOJSON(CARTO.CARTO.ST_MAKEELLIPSE(ST_POINT(-70,40), 2, 10, 45, 'kilometers', 4)):coordinates[0]) AS POINT_ARR
UNION ALL
SELECT '90 DEG' AS TYPE, TO_ARRAY(ST_ASGEOJSON(CARTO.CARTO.ST_MAKEELLIPSE(ST_POINT(-70,40), 2, 10, 90, 'kilometers', 4)):coordinates[0]) AS POINT_ARR
UNION ALL
SELECT '135 DEG' AS TYPE, TO_ARRAY(ST_ASGEOJSON(CARTO.CARTO.ST_MAKEELLIPSE(ST_POINT(-70,40), 2, 10, 135, 'kilometers', 4)):coordinates[0]) AS POINT_ARR
UNION ALL
SELECT '180 DEG' AS TYPE, TO_ARRAY(ST_ASGEOJSON(CARTO.CARTO.ST_MAKEELLIPSE(ST_POINT(-70,40), 2, 10, 180, 'kilometers', 4)):coordinates[0]) AS POINT_ARR
UNION ALL
SELECT '-135 DEG' AS TYPE, TO_ARRAY(ST_ASGEOJSON(CARTO.CARTO.ST_MAKEELLIPSE(ST_POINT(-70,40), 2, 10, -135, 'kilometers', 4)):coordinates[0]) AS POINT_ARR
UNION ALL
SELECT '-90 DEG' AS TYPE, TO_ARRAY(ST_ASGEOJSON(CARTO.CARTO.ST_MAKEELLIPSE(ST_POINT(-70,40), 2, 10, -90, 'kilometers', 4)):coordinates[0]) AS POINT_ARR
UNION ALL
SELECT '-45 DEG' AS TYPE, TO_ARRAY(ST_ASGEOJSON(CARTO.CARTO.ST_MAKEELLIPSE(ST_POINT(-70,40), 2, 10, -45, 'kilometers', 4)):coordinates[0]) AS POINT_ARR
UNION ALL
SELECT '-5 DEG' AS TYPE, TO_ARRAY(ST_ASGEOJSON(CARTO.CARTO.ST_MAKEELLIPSE(ST_POINT(-70,40), 2, 10, -5, 'kilometers', 4)):coordinates[0]) AS POINT_ARR
)

SELECT D.TYPE, (F.INDEX)::VARCHAR AS POINT_INDEX, TO_GEOGRAPHY(OBJECT_CONSTRUCT('type', 'Point', 'coordinates', F.VALUE)) AS GEOG
FROM DATA D,
LATERAL FLATTEN(INPUT=>D.POINT_ARR) F

Screenshots

[vdelacruzb]

Hi @scoddou,
Indeed I would say angle is positive clockwise relative to the y-axis north. So I think with the change done in: #477
Users should be able to understand as it also matches turf docs.

[vdelacruzb]

Just merged: #477 so this issue can be closed with it.