Square/Hexbin aggregation

Context

For squares/hexbins aggregation, Builder takes a bin size based on the zoom level at the moment of the map creation. After that, the bin size remains static regardless of the zoom level.

The current query to create those maps is:

SELECT 
  CDB_HexagonGrid ( 
    ST_Expand(
      !bbox!, 
      CDB_XYZ_Resolution(ZOOM_LEVEL) * 12), 
    CDB_XYZ_Resolution(ZOOM_LEVEL) * 12) 
  AS cell

while in the Editor it was:

SELECT 
  CDB_HexagonGrid(
    ST_Expand(
      !bbox!, 
      greatest(!pixel_width!,!pixel_height!) * 24), 
    greatest(!pixel_width!,!pixel_height!) * 24) 
  AS cell

Steps to Reproduce

1. Create a map with a point’s dataset
2. Select squares or hexbins aggregation and set a size
3. Zoom in/out

Current Result

The map is instantiated with a fixed bin size based on the initial zoom level, so the grid doesn’t change at different zoom levels

Expected result

Bins should resize on each zoom level according with the pixel size value used as a parameter.

Additional info

If we decide to have a fixed bin size, we should use a different unit than pixels for setting it, like meters.

[jgoizueta]

I find the present implementation inconsistent in that users define the grid size in pixels (screen units) but the grid is actually set in geographic units (onscreen size changes with zoom, size is earth-relative actually as @ernesmb notes).

But I think there might be use cases for both the current behaviour and the previoius one. What I’d like to see is an option in the UI to choose the grid size units:

• If meters (km, etc) are selected, the gridding is earth-wise (as now, pixel size will change with zoom)
• If pixels are selected, the grid is screen-wise (earth-relative size in meters will change with zoom)

Just my 2c.

[ramiroaznar]

Let’s close this issue.