Re: [OctDev] new package ncArray 1.0.0

[Alexander B. <bar...@gm...>]

On Wed, Jul 18, 2012 at 3:14 PM, Michael Goffioul
<mic...@gm...> wrote:
> On Wed, Jul 18, 2012 at 12:44 PM, Alexander Barth
> <bar...@gm...> wrote:
>>
>> Sorry for poor spelling in my last email. The email was sent
>> inadvertently before I could check it.
>> Source packages are here:
>>
>>
>> http://modb.oce.ulg.ac.be/mediawiki/upload/Alex/ncArray/ncarray-1.0.0.tar.gz
>>
>> http://modb.oce.ulg.ac.be/mediawiki/upload/Alex/ncArray/ncarray-html.tar.gz
>>
>> Can somebody update the server?
>> Best regards,
>> Alex
>>
>>
>> On Wed, Jul 18, 2012 at 1:30 PM, Alexander Barth
>> <bar...@gm...> wrote:
>> > Dear all,
>> >
>> > I have released a new package called ncArray for manipulating netcdf
>> > files. It depends on the functions ncread, ncwrite and ncinfo from
>> > octcdf. Maybe someday, these functions will be implemented in octave
>> > (as they are in matlab) and ncArray will be independent from octcdf.
>> >
>> > The package allows to access a single or a collection of NetCDF files
>> > (or OPeNDAP URLs) as a multi-dimensional array.
>> > For a collection of NetCDF files, the variables are concatenated along
>> > a given dimension similar to the command cat. The ncArray object
>> > contains only a reference to the underlying files. The data is loaded
>> > only, if the array is indexed.
>> >
>> > For example, if the current directory containts file1.nc, file2.nc and
>> > file3.nc and each file contains the 20 x 30 variable temp, then:
>> >
>> > A = ncCatArray(3,'file*.nc','temp')
>> >
>> > would create and array A of size 20 x 30 x 3 without actually loading
>> > the files. Only when the array is index e.g., A(:,:,2:3), the file
>> > file2.nc and file3.nc are loaded.
>> >
>> > Also, reduction operators are implement. For example, sum(A,3) would
>> > compute the sum over the 3rd dimension and sequentially loading all
>> > files.
>> >
>> > ncArray allows thus to write code for dataset which are too big to be
>> > loaded in memory and still to write code that are independent on the
>> > way the data is stored and how a data set is split across files.
>> >
>> > More example how to use this package are available here:
>> > http://modb.oce.ulg.ac.be/mediawiki/index.php/NcArray
>> >
>> > Best rega
>>
>
>  Is there a reason not to integrate these functions into the octcdf package
> directly?
>
> Michael.
>

Yes, ncArray contains pure m-scripts that work also with matlab.
octcdf is mostly written in C++ code that are specific to octave. A
matlab user thus only needs the package ncArray.

Best regards,
Alex