Hi Edzer, Thanks for the feedback
> - what would be the advantage to GDAL users using this interface, as > opposed to reading/writing directly using the HDF or NetCDF4 interfaces? libnetcdf only handle netCDF datasets (and compatible HDF5 files). libhdf4 only handles HDF4 files. libhdf5 only handles HDF5 files, etc. So the idea is to have an abstract data model, like the 2D raster side, so that users do not need to deal with the particular API of each underlying library. > Will it for instance be able to figure out coordinate reference systems, > and identify which dimensions are spatial dimensions? When possible (like with netCDF CF conventions), yes One feedback I got was that the GDALDimension object should have some metadata to indicate the nature of the dimension, when it is known, like X, Y, Elevation, Time., that's a goal > - will this interface also give access to e.g. irregular dimensions (for > rectlinear grids), bounds of dimensions, What do you mean exactly by irregular dimensions / bounds of dimensions ? Can you link to dataset samples ? > or two-dimensional dimension > values like longitude values for each grid cell (for curvilinear grids)? Yes, the link from the dimension to the variable (GDALDimenson::indexing_ariable) should also support two-dimensional variables. > > - will handling of time values follow the netcdf pattern (e.g. integer > values, along with a udunits2 time unit), or be like a double > representing seconds since 1970-01-01, or be something more higher level > like it is in OGR's OFTDateTime? I guess that we will reflect the choice of the data producer / format constraints. Not sure if we can / must always convert to Unix epoch (with double precision). Perhaps we could have an open option where we would normalize to Unix epoch when possible, or otherwise preserve the raw values. > > - will it also be possible to read e.g. spatial raster bands on a lower > than native spatial resolution, like RasterIO() does? Yes, that's the purpose of the array_stride argument of GDALAbstractMDArray::Read(). If set to something different from NULL or [1, 1, 1...], subsampling will occur. I don't intend to provide other than nearest neighbour resampling at that point. Even -- Spatialys - Geospatial professional services http://www.spatialys.com _______________________________________________ gdal-dev mailing list gdal-dev@lists.osgeo.org https://lists.osgeo.org/mailman/listinfo/gdal-dev
