Flipping Coordinates

flipCoordinates

The flipCoordinates function swaps the coordinates of a point, ring, polygon, or multipolygon. This is useful, for example, when converting between coordinate systems where the order of latitude and longitude differs.

flipCoordinates(coordinates)

Input Parameters

• coordinates — A tuple representing a point (x, y), or an array of such tuples representing a ring, polygon, or multipolygon. Supported input types include:
  • Point: A tuple (x, y) where x and y are Float64 values.
  • Ring: An array of points [(x1, y1), (x2, y2), ...].
  • Polygon: An array of rings [ring1, ring2, ...], where each ring is an array of points.
  • Multipolygon: An array of polygons [polygon1, polygon2, ...].

Returned Value

The function returns the input with the coordinates flipped. For example:

• A point (x, y) becomes (y, x).
• A ring [(x1, y1), (x2, y2)] becomes [(y1, x1), (y2, x2)].
• Nested structures like polygons and multipolygons are processed recursively.

Examples

Example 1: Flipping a Single Point

SELECT flipCoordinates((10, 20)) AS flipped_point

┌─flipped_point─┐
│ (20,10)       │
└───────────────┘

Example 2: Flipping an Array of Points (Ring)

SELECT flipCoordinates([(10, 20), (30, 40)]) AS flipped_ring

┌─flipped_ring──────────────┐
│ [(20,10),(40,30)]         │
└───────────────────────────┘

Example 3: Flipping a Polygon

SELECT flipCoordinates([[(10, 20), (30, 40)], [(50, 60), (70, 80)]]) AS flipped_polygon

┌─flipped_polygon──────────────────────────────┐
│ [[(20,10),(40,30)],[(60,50),(80,70)]]        │
└──────────────────────────────────────────────┘

Example 4: Flipping a Multipolygon

SELECT flipCoordinates([[[10, 20], [30, 40]], [[50, 60], [70, 80]]]) AS flipped_multipolygon

┌─flipped_multipolygon──────────────────────────────┐
│ [[[20,10],[40,30]],[[60,50],[80,70]]]             │
└───────────────────────────────────────────────────┘