Hi Walter, On Feb 20, 2015, at 4:28 PM, Walter Landry <[email protected]> wrote:
> Hello, > > Is there a recommended way to indicate whether a field in a record of > a table is invalid? For example, for double's, I could use NaN. But > that does not work if I actually want to store a NaN. Also, I need > something that works for everything: strings, bools, etc. I could do > it by adding a char array column and checking the bit corresponding to > a column. It is a bit clunky, and I want to make sure I am not > reinventing the wheel. > Unfortunately, there is no way in HDF5 to indicate an invalid value in a dataset. We saw HDF5 files where a dataset with 8-bit “quality flags” was stored along with the original (numeric) dataset to indicate the valid elements. Since it contained mostly 1 and 0, it compressed well and didn’t create much storage overhead. Elena ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Elena Pourmal The HDF Group http://hdfgroup.org 1800 So. Oak St., Suite 203, Champaign IL 61820 217.531.6112 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > Thanks, > Walter Landry > > _______________________________________________ > Hdf-forum is for HDF software users discussion. > [email protected] > http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org > Twitter: https://twitter.com/hdf5 _______________________________________________ Hdf-forum is for HDF software users discussion. [email protected] http://lists.hdfgroup.org/mailman/listinfo/hdf-forum_lists.hdfgroup.org Twitter: https://twitter.com/hdf5
