Jeff Whitaker <jswhit@xxxxxxxxxxx> writes:
> Mary Haley wrote:
>> Hi all,
>> This is a bit of a late announcement, but NCL V4.3.1 and PyNIO V1.2.0
>> have support built-in for reading and writing netCDF-4 classic files
>> on systems where netcdf-4.0-beta1 is supported.
>> With NCL, you can write a netCDF-4 classic file by calling the
>> "setfileoption" procedure with the "format" option before you call
>> "addfile" to create a netCDF-4 classic 4 file:
>> a = addfile("file.nc","c")
>> You can further specify a compression level:
>> Similar code exists for PyNIO:
>> import Nio
>> opt = Nio.options()
>> opt.Format = "netcdf4classic"
>> opt.CompressionLevel = 5
>> fout = Nio.open_file("file.nc","c",opt)
>> For more information, see the NCL "setfileoption" or PyNIO documentation:
>> For download:
> Mary: Can you turn the shuffle filter on with setfileoption? I've
> found that it can really improve the compression ratios when used in
> conjunction with zlib compression in netcdf-4 files.
Howdy Mary and Jeff!
Just wanted to point out that compression is a per-variable feature,
not a per-file feature.
That is, different variables in the file can have different
compression factors (or none at all).
Ed Hartnett -- ed@xxxxxxxxxxxxxxxx