Hi, I took this as an opportunity to check osm4j's support for history files. From what I understand the main difference to ordinary data files is that elements with the same id appear multiple times and they carry the 'visible' attribute. During testing I noted that I would not find any nodes with the visibility set to false, which appears strange to me? Can this be true, or is there likely something wrong with either the data or the code that processes it?
I've set up a minimal example that counts and sums up the visibility of each entity type in Bremen: https://github.com/topobyte/osm4j-examples/blob/master/src/main/java/de/topobyte/osm4j/examples/history/HistoryVisibilityStats.java Here's the output: nodes: 2389608 visible, 0 invisible ways: 729714 visible, 27604 invisible relations: 67500 visible, 1632 invisible The data file used is this: http://download.geofabrik.de/europe/germany/bremen.osh.pbf Thank you for any hints, Sebastian On Mon, 20 Feb 2017 01:18:00 +0100 Frederik Ramm <frede...@remote.org> wrote: > Hi, > > "full history" files are kind of a niche interest, but they can be > useful to analyze some things like "how many different people have > added a certain tag", or "how has an object evolved over time", and > so on. They can also be used to reconstruct the complete data set for > any given timestamp in the past (minus, of course, redactions). > > I'm happy to announce that the Geofabrik download server now has full > history files for all regions served. These files (called ".osh.pbf") > can for example be processed with the Osmium library and the osmium > command line tool. If you want to run analyses on them without C++ > coding, Osmium can convert them to a text-based format ("OPL") that is > then accessible for grep et al. > > The full history files will be updated weekly. > > Bye > Frederik > _______________________________________________ dev mailing list dev@openstreetmap.org https://lists.openstreetmap.org/listinfo/dev
