On 3/7/11 10:28 AM, Christopher Barker wrote: > Hi folks, > > I'm setting out to write some code to access and work with ragged arrays > stored in netcdf files. It dawned on me that ragged arrays are not all > that uncommon, so I'm wondering if any of you have any code you've > developed that I could learn-from borrow from, etc. > > note that when I say a "ragged array", I mean a set of data where the > each row could be a different arbitrary length: > > 1, 2, 3, 4 > 5, 6 > 7, 8, 9, 10, 11, 12 > 13, 14, 15 > ... > > In my case, these will only be 2-d, though I suppose one could have a > n-d version where the last dimension was ragged (or any dimension, I > suppose, though I'm having trouble wrapping my brain around what that > would look like... > > I'm not getting more specific about what I think the API should look > like -- that is part of what I'm looking for suggestions, previous > implementations, etc for. > > Is there any "standard" way to work with such data? > > -Chris >
Chris: The netcdf4-python modules reads netcdf vlen arrays and returns numpy object arrays, where the elements of the object arrays are themselves 1d numpy arrays. I don't think there is any other way to do it. In your example, the 'ragged' array would be a 1d numpy array with dtype='O', and the individual elements would be 1d numpy arrays with dtype=int. Of course, these arrays are very awkward to deal with and operations will be slow. -Jeff -- Jeffrey S. Whitaker Phone : (303)497-6313 Meteorologist FAX : (303)497-6449 NOAA/OAR/PSD R/PSD1 Email : jeffrey.s.whita...@noaa.gov 325 Broadway Office : Skaggs Research Cntr 1D-113 Boulder, CO, USA 80303-3328 Web : http://tinyurl.com/5telg _______________________________________________ NumPy-Discussion mailing list NumPy-Discussion@scipy.org http://mail.scipy.org/mailman/listinfo/numpy-discussion
