There is a lake in northern Quebec, Canada that is comprised of 735 ways and 207982 nodes. This is causing pretty severe performance issues when the lake is loaded in JOSM, and since the lake is part of several boundaries and I’ve been doing boundary work in Quebec I’ve been seeing it a lot. I also imagine it causes extra work for anyone making tiles or doing other calculations. I’d really like to simplify these ways.
Actually doing the work in JOSM is super easy, just a few steps: Download the lake, select the ways, then Tools>Simplify Way. I’ve actually already done it and it give the following result, when simplifying to the default 3m accuracy:
207982 → 64576 nodes
143,406 nodes removed or 69% (nice)
There are other lakes in the area drawn similarly. I estimate that I’d be deleting at least 200,000 nodes between them.
My only concern is that the change is very large. JOSM offers/requires breaking it into chunks of 1,000 or 10,000 but that’s still going to be 20 or 200 changes submitted. Is there some better way of submitting a change like this? Or anything else I should be aware of before submitting?
56 posts - 14 participants
Ce sujet de discussion accompagne la publication sur https://community.openstreetmap.org/t/simplifying-lake-with-200-000-nodes/97259