A Friday 25 March 2011 00:05:19 Adriano Vilela Barbosa escrigué: > Yes, the problem is when assigning a string (any string, not only one > obtained from a numpy array) to the CArray. The trailing '\x00' > items are simply lost. In the examples you gave before with numpy > arrays, you could still see the trailing '\x00' elements were there > by doing a.data[:]; however, after assigning the string to the > CArray, even if I do > > fid.root.table.bin_table[0].data[:] > > I can't see anything. Is this really the way this is supposed to > work?
Probably not, but as I said before, trying to pack binary data as strings is asking for problems. Please use a bytes array instead. If what you are after is performance, then I'd say that Blosc/VLArray is the way to go. > In my previous, long (sorry about that) email I told you the reason > I'm using strings: because of OpenCV. However, I converted my OpenCV > images (actually, optical flow frames) to numpy arrays and I'm > trying to store them in a CArray. The data can be seen as a (n_rows, > n_cols, n_frames) array, where n_rows and n_cols are the number of > rows and columns in each frame, respectively, and n_frames is the > number of frames. The optical flow values are represented as int16. > Initially, I did > > array_shape = (n_rows,n_cols,n_frames) > array_atom = tables.Int16Atom() > > and that works fine, although this is much slower and results in > quite bigger files (compared to the string approach). Next, I did > > array_shape = (n_frames,) > array_atom = tables.Int16Atom((n_rows,n_cols)) > > in the hope that this would be faster and more compression efficient. > However, when creating the second CArray (I need two of them, for > the horizontal and vertical pixel displacements) I get the following > error: [clip] > > This is the memory error I mentioned before. Any ideas why this > happens? Could you send a self-contained example reproducing your problem? -- Francesc Alted ------------------------------------------------------------------------------ Enable your software for Intel(R) Active Management Technology to meet the growing manageability and security demands of your customers. Businesses are taking advantage of Intel(R) vPro (TM) technology - will your software be a part of the solution? Download the Intel(R) Manageability Checker today! http://p.sf.net/sfu/intel-dev2devmar _______________________________________________ Pytables-users mailing list Pytables-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/pytables-users
