A Tuesday 13 April 2010 09:15:46 Stamminger, Johannes escrigué: > > easily, so I suppose that it is fine if you send more of these (although > > if you can come up with a PDF file would be better). > > In principle absolutely correct. Thus it contains calculations and with > pdf no one could verify them any longer (I found already several times - > until now only *before* having posted it - wrong cell references inside > them). This way someone wondering might check them ... so I personally > would prefer to stay with the OO-xls for best compatibility ... ?
Honest, do not expect people to check the correctness of your computations. They will rather tend to trust your report, so always double check that your data is correct before sending it to the list. > > use the shuffle filter in combination with zlib. In many circumstances, > > shuffle may buy you significant additional compression ratio. This is > > Good to know. You know of whether this is shown in an example? I suppose there are different examples spread in the web, but just to give you an idea, this would work: http://www.pytables.org/docs/manual/ch05.html#ShufflingOptim > > something that zip cannot do (it can only compress streams of bytes, as > > it has not the notion of ints/floats). > > > > > With big chunksize both, performance and file size, degrade by a large > > > factor. Worst example was to have 819K leading to a file of 513M (50 > > > arrays with 16384 bytes each, compression 0, chunk size 32K). > > > > Uh, you lost me. What is 819 KB, the chunksize? > > Oh no, this is the size of the data having written to the hdf: 50 arrays > of size 16384 bytes each. Written to hdf with compression level 0, chunk > size 32K. Using a 32 KB chunksize is not that big, but I'd say it is a normal to small size :-/ And requiring 513 MB to save just 819 KB is completely unusual. I'd report this to THG too. -- Francesc Alted _______________________________________________ Hdf-forum is for HDF software users discussion. [email protected] http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org
