Traversing the globe at one resolution

[henriktorget]

Hello from Hub Ocean in Norway! We are creating a platform for anyone who wants to share and consume data related to the ocean.

I am currently creating hexagons within our PostGIS database to divide up huge queries of data. But I think that H3 would be a better tool for that job now that we have our pipelines in python.

I am lacking example code for how to do this with H3.

I want to define a grid at a fixed resolution that I can iterate over. So that I can perform a SELECT on each hex defined as a polygon / list of points that postGIS can consume.

Anyone who would like to help, or know where I can look?

Regards, Henrik :D

[nrabinowitz]

There are two PostgreSQL extensions for H3, which might be helpful: https://h3geo.org/docs/community/bindings#postgresql

To iterate over the entire world, the easiest option at the moment is to start with the 122 resolution 0 indexes and then take their children at the desired resolution. For example:

my_resolution = 5
for index_0 in h3.get_res0_indexes():
  for child_index in h3.h3_to_children(index_0, my_resolution):
    polygon = h3.h3_to_geo_boundary(child_index, geo_json=True)
    # do something with the polygon

[henriktorget]

Thanks a lot for your help! Just a sanity check; will this - at one single resolution - not overlap or miss any area of the globe?

[nrabinowitz]

Thanks a lot for your help! Just a sanity check; will this - at one single resolution - not overlap or miss any area of the globe?

Sorry for the slow reply: Yes, this will cover the whole globe with no overlaps.