rdblue commented on PR #240: URL: https://github.com/apache/parquet-format/pull/240#issuecomment-2637775619
Sorry to introduce this issue! I didn't realize that my rationale conflicted with what GeoParquet was already doing. My initial concern was this language: > X must be longitude and Y must be latitude. This explicitly overrides the axis order defined in CRS This specifically states that the order of dimensions in bounding box metadata must differ from the CRS in some cases. To me, that seems like a big implementation risk if people don't know to swap them. In addition, the names that we use for the bounding box values (xmin, ymin, xmax, ymax) are misleading when the WKB values use x=latitude, y=longitude but x and y in metadata must be x=longitude, y=latitude. Also, please correct me if I'm wrong here. My current understanding is that the WKB data will correspond to the CRS even if the bounding box dimensions override it. I do prefer a spec in which this ambiguity doesn't exist. I also pointed out that it is strange that we allow xmin > xmax and ymin > ymax, depending on whether the x or y dimension is longitude. That is what led to the latest change that points out that y may be longitude. And I'm glad we added the clarification so that we caught this problem! Would it work to change this to use `longitude` and `latitude` specifically? We could have longitude, latitude, z, and m dimensions, which would probably be clear. The downside is that it may still be difficult for people to produce this if they need to understand the CRS in order to correctly map Y to longitude in some cases. I think we want to avoid needing everything to understand the CRS, but this may require a specific flag to capture whether X and Y in the data values need to be reversed in metadata. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: issues-unsubscr...@parquet.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org --------------------------------------------------------------------- To unsubscribe, e-mail: issues-unsubscr...@parquet.apache.org For additional commands, e-mail: issues-h...@parquet.apache.org
