On 21.06.2011, at 8:35PM, Christopher Barker wrote: > Robert Kern wrote: >> https://raw.github.com/numpy/numpy/master/doc/neps/npy-format.txt > > Just a note. From that doc: > > """ > HDF5 is a complicated format that more or less implements > a hierarchical filesystem-in-a-file. This fact makes satisfying > some of the Requirements difficult. To the author's knowledge, as > of this writing, there is no application or library that reads or > writes even a subset of HDF5 files that does not use the canonical > libhdf5 implementation. > """ > > I'm pretty sure that the NetcdfJava libs, developed by Unidata, use > their own home-grown code. netcdf4 is built on HDF5, so that qualifies > as "a library that reads or writes a subset of HDF5 files". Perhaps > there are lessons to be learned there. (too bad it's Java) > > """ > Furthermore, by > providing the first non-libhdf5 implementation of HDF5, we would > be able to encourage more adoption of simple HDF5 in applications > where it was previously infeasible because of the size of the > library. > """ > > I suppose this point is still true -- a C lib that supported a subset of > hdf would be nice. > > That being said, I like the simplicity of the .npy format, and I don't > know that anyone wants to take any of this on anyway.
Some late comments on the note (I was a bit surprised that HDF5 installation seems to be a serious hurdle to many - maybe I've just been profiting from the fink build system for OS X here - but I also was not aware that the current netCDF is built on downwards-compatibility to the HDF5 standard, something useful learnt again...:-) Some more confusion arose when finding that the NCAR netCDF includes C and Fortran versions: http://www.unidata.ucar.edu/software/netcdf/ but they also depend actually on HDF5 for netCDF 4 access. While the Java version appears not to, it also only provides *read* access to those formats, so it probably would not be of that much help anyway. The netCDF4-Python package mentioned before http://code.google.com/p/netcdf4-python/ unfortunately builds on HDF5 again, same for the PyNIO module http://www.pyngl.ucar.edu/Nio.shtml which is probably explained by the above dependencies. Finally, the former Scientific.IO NetCDF interface is now part of scipy.io, but I assume it only supports netCDF 3 (the documentation is not specific about that). This might be the easiest option for a portable data format (if Matlab supports it). Cheers, Derek _______________________________________________ NumPy-Discussion mailing list [email protected] http://mail.scipy.org/mailman/listinfo/numpy-discussion
