Hi Brad, Il 19/01/2012 04:13, Brad Buran ha scritto: > Hi Antonio: > > The user block I am referring to is a region at the beginning of the > file that is reserved for user metadata. I pasted the description > from the HDF5 documentation below > (http://www.hdfgroup.org/HDF5/doc1.6/UG/08_TheFile.html). I believe > H5Py added this feature > (http://code.google.com/p/h5py/source/detail?r=8a3010d07e14); however, > I don't see a similar way to do this via PyTables. I suppose I could > use h5py to create a blank HDF5 file with the required user block then > reopen it in PyTables, however, I'd like to minimize code dependencies > and everything I've written is built around PyTables rather than h5py. >
Sorry, for the misunderstanding, I was not aware of this feature. Please file a feature request on https://github.com/PyTables/PyTables best regards > Thanks! > Brad > > Documentation from HDF5: > > User-block size > herr_t H5Pset_userblock (hid_t plist, hsize_t size) > herr_t H5Pget_userblock (hid_t plist, hsize_t *size) > > The user-block is a fixed-length block of data located at the > beginning of the file and which is ignored by the HDF5 library. This > block is specifically set aside for any data or information that > developers determine to be useful to their application but that will > not be used by the HDF5 library. The size of the user-block is defined > in bytes and may be set to any power of two, with a minimum size of > 512 bytes (i.e. 512, 1024, 2048, etc). This property is set with > H5Pset_userblock and queried via H5Pget_userblock. > > For example, if an application was thought to reqire a 4K > user-block, that could be set with the following function call: > status = H5Pset_userblock(fcpl_id, 4096) > The property list could later be queried with > status = H5Pget_userblock(fcpl_id, size) > and the value 4096 would be returned in the parameter size. > > > On Wed, Jan 18, 2012 at 4:52 PM, Antonio Valentino > <antonio.valent...@tiscali.it> wrote: >> Hi Brad, >> >> Il 18/01/2012 21:49, Brad Buran ha scritto: >>> Is there a way to set the size of the user block when creating a file >>> in PyTables? This would be useful for using PyTables to generate >>> Matlab 7.3 compatible files. >>> >>> Brad >> >> Try to use CArrays and set the chunkshape explicitly >> >> http://pytables.github.com/usersguide/libref.html#tables.File.createCArray >> >> Does it answers your question? >> >> >> best regards >> >> >> -- >> Antonio Valentino >> -- Antonio Valentino ------------------------------------------------------------------------------ Keep Your Developer Skills Current with LearnDevNow! The most comprehensive online learning library for Microsoft developers is just $99.99! Visual Studio, SharePoint, SQL - plus HTML5, CSS3, MVC3, Metro Style Apps, more. Free future releases when you subscribe now! http://p.sf.net/sfu/learndevnow-d2d _______________________________________________ Pytables-users mailing list Pytables-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/pytables-users
