On Wed, Feb 4, 2015 at 2:25 PM, Sjaardema, Gregory D <gdsjaar@xxxxxxxxxx>
wrote:
> It isn¹t usually a constant file size multiplier, it is typically an
> offset in file size. In other words, typically the file will be somewhat
> larger for the hdf5-based version (with no compression) than a
> corresponding netcdf-based classic file, but the size differential will be
> smaller as the overall file sizes increase.
>
unless there are poor settings for chunk sizes -- the defaults used to be
horrible for 1-d arrays (or with arrays with one or more very small
dimension) -- though I think recent versions fixed this. Might be worth
checking out though.
-CHB
> Note that with the netcdf4 hdf5-based file, you can also enable
> compression with the "-d #² and -s options. Œ#¹ can rance from 1 to 9,
> but values of 1 or 2 along with the shuffle (-s) option typically give
> good results.
>
> ..Greg
>
> On 2/4/15, 3:16 PM, "Nico Schlömer" <nico.schloemer@xxxxxxxxx> wrote:
>
> >Hi all,
> >
> >When converting classical netCDF files to their modern format (compare
> >the thread starting at [1]) I noticed that the file size blows up
> >considerably, e.g.
> >```
> >$ du -sh pacman-classical.e
> >40K pacman-classical.e
> >$ nccopy -k hdf5 pacman-classical.e pacman.e
> >$ du -sh pacman.e
> >4.1M pacman.e
> >```
> >with `pacman-classical.e` from [2]. I'm not too worried about this
> >now, but is this something you would expect?
> >
> >Cheers,
> >Nico
> >
> >
> >[1]
> >
> http://www.unidata.ucar.edu/mailing_lists/archives/netcdfgroup/2015/msg000
> >19.html
> >[2] http://win.ua.ac.be/~nschloe/other/pacman.e
> >
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