Nan,
We use our Netcdf-Java Toolbox for Matlab (http://njtbx.sourceforge.net) to
*access* NetCDF, OPenDAP and NcML, as well as utilize CF-Conventions, and
this toolbox relies on NetCDF-Java to do the heavy lifting. (there will be
a new release of these tools later today, BTW...)
For writing NetCDF files, we still use the NetCDF Toolbox or SNCTOOLS, both
of which depend on mex files. But if you have Matlab 2008b or later, the
required mex files are included with your Matlab distribution from Mathworks
-- you don't need to obtain them elsewhere.
The only thing you need for 2008b or later is the m-file distribution of the
NetCDF Toolbox or SNCTOOLS, which I get via SVN following the instructions
at:
http://mexcdf.sourceforge.net/
I know it's possible to write entire files using NetCDF-Java, but my
understanding is that it's still not possible to put an existing file in
redefine mode, so you can't open an existing netcdf file for writing and
start adding things.
-Rich
On Wed, Aug 26, 2009 at 10:41 AM, Nan Galbraith <ngalbraith@xxxxxxxx> wrote:
> Hi All -
>
> It seems that various people are now using a Matlab interface to the Java
> library to create NetCDF files. Is there updated documentation on how to
> do this, or is this 2007 email thread the last word on the subject?
>
> The Unidata documentation still implies that Matlab->Java-NetCDF is
> read-only, unless I'm looking in the wrong part of the site.
>
> This may be a moot point soon, with the new version of Matlab supporting
> NetCDF, but we seem to be a long way from acquiring a site license for
> that here at WHOI.
>
> Thanks -
> Nan
>
>
> Steve Loch wrote:
>
>> At BODC we use Matlab and Java in combination although we tend to use the
>> former for data processing and the latter for visualisation.
>>
>> 1) It may be worth mentioning that there is a NetCDF toolbox which uses
>> MEX files. So this is the non-Java way to write NetCDF from Matlab. See the
>> Unidata web site.
>>
>> Sticking with the Java approach.
>> 2) Minor point but rather than tweaking the classpath use the dynamic
>> javaaddpath. 3) The manual looks to be out of date because I remember
>> converting ArrayAbstract to Array very recently. The code we use to write
>> variables in Java looks like this.
>>
>> String chanam = ch.getChannelName(true); // variable name
>>
>> switch(ch.getType()){
>> case 'I':
>> aa = Array.factory(int.class, ch.getShape(), // getShape
>> is the array of Dimensions
>> ch.getDataInt());
>> // The data array
>> break;
>> case 'D':
>> aa = Array.factory(double.class, ch.getShape(),
>> ch.getDataDouble(false));
>> break;
>> case 'F':
>> aa = Array.factory(float.class, ch.getShape(),
>> ch.getDataFloat(false));
>> break;
>> default: throw new RuntimeException("Unrecognised type");
>> }
>> qxffile.write(chanam,aa); //qxffile will be the NetcdfFileWriteable
>>
>> This can be carried over to Matlab very easily.
>>
>> Steve Loch.
>> BODC
>>
>>
>>
>>> "Rich Signell" <rsignell@xxxxxxxx> 09/07/2007 15:50 >>>
>>>>>
>>>>>
>>>> Roger,
>>
>> I haven't tried to write files from Matlab using NetCDF Java, but here
>> is an example of a Matlab using some of the higher level functionality
>> within NetCDF-Java to access and plot an isosurface from a 3D
>> dimensionless vertical coordinate ocean model:
>>
>> http://stellwagen.er.usgs.gov/rps/share/java_isosurface_demo2.m
>> If you follow the instructions carefully at the top of the m-file to
>> download the .jar file and edit the classpath, it should just work for
>> you, as it accesses the model data via OpenDAP, which is supported by
>> NetCDF-Java.
>>
>> Let me know if it doesn't work.
>>
>> -Rich
>>
>> On 7/9/07, Roger GALLOU (AGO) <roger.gallou@xxxxxx> wrote:
>>
>>
>>> Hello,
>>>
>>> I hope I'm on the good users list.
>>> I'm working with Matlab R2006b on Windows. I 'm intesresting by the
>>> NetCDF Java package to access to data files for read and write.
>>> I've found some examples, I try on Matlab, in the document : NetCDF Java
>>> Users' Manuel (page 33-34).
>>>
>>> I need some help to call some classes of the librairy nc2.2.jar,
>>> particulary for writing files :
>>> all the classes type ArrayInt (Double, ...) for dimensions D1, D2, D3 ...
>>>
>>> I success to manage dimension, attribut, but I don't manage to create a
>>> array of data for any dimension I know.
>>> In Matlab, the instruction :
>>> ucar.ma2.ArrayInt.D3(2, latDim.getLength(), lonDim.getLength()) answers
>>> that the method D3 doesn't exist.
>>> I can't call with the "$" character as it is declared in the package
>>> ucar.ma2.
>>> (ex : ArrayInt$D1).
>>>
>>> Is there anybody who have encounter this king of problem ? If yes, could
>>> he/she bring me some help ?
>>> In extension, if anybody has some informations for writing NetCDF files
>>> with Java librairies in Matlab, I'm interesting.
>>>
>>> Thanks by advance.
>>>
>>> Roger GALLOU
>>> roger.gallou@xxxxxx 02 98 05 43 21 (FRANCE)
>>>
>>>
>>>
>>>
>>> ===============================================================================
>>> To unsubscribe netcdf-java, visit:
>>> http://www.unidata.ucar.edu/mailing-list-delete-form.html===============================================================================
>>>
>>>
>>>
>>
>>
>>
>>
>
>
> --
> *******************************************************
> * Nan Galbraith (508) 289-2444 *
> * Upper Ocean Processes Group Mail Stop 29 *
> * Woods Hole Oceanographic Institution *
> * Woods Hole, MA 02543 *
> *******************************************************
>
>
>
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--
Dr. Richard P. Signell (508) 457-2229
USGS, 384 Woods Hole Rd.
Woods Hole, MA 02543-1598
