The purpose of aggregation is quite simple -- it has to show which area has which amount of some objects/properties. And it must be mathematically consistent.
If a cell is said to be a sum of 7 underlying cells, then their sum of objects must equal to this cell's sum of objects, which is not the case in H3.
You can just hope that the diff of these values is within acceptable limits, and that company management never tries to drill down into your data, and does not put all the blame for some incorrectness on you.
So, even though H3 cells kinda add-up, they actually don't, and you have to either just plainly hope, or take care of data, as I decided to do.
You'd never had this dilemma, nor need to cure the data, with a rectangular grid in either UTM projection, or Google pseudo-Mecrator, both of which preserve horizontal/vertical aspects and are perfect for such aggregative cell grids.
> If a cell is said to be a sum of 7 underlying cells, then their sum of objects must equal to this cell's sum of objects, which is not the case in H3.
If you are using an H3 index as an index to the aggregate of the logically-contained cells at some specified level, it absolutely is true (in this case, the exact geographic border is the border of the set of contained cells ay thr specified level, not the border of the higher-level cell specified by the index.)
If a cell is said to be a sum of 7 underlying cells, then their sum of objects must equal to this cell's sum of objects, which is not the case in H3.
You can just hope that the diff of these values is within acceptable limits, and that company management never tries to drill down into your data, and does not put all the blame for some incorrectness on you.
So, even though H3 cells kinda add-up, they actually don't, and you have to either just plainly hope, or take care of data, as I decided to do.
You'd never had this dilemma, nor need to cure the data, with a rectangular grid in either UTM projection, or Google pseudo-Mecrator, both of which preserve horizontal/vertical aspects and are perfect for such aggregative cell grids.