HI, Thanks for the input. On Tue, Oct 23, 2012 at 7:41 AM, Mitchell, Scott - IS < scott.mitch...@exelisinc.com> wrote:
> Michele, > > > > I’m dealing with a similar timestamped data streams and use Packet Tables > almost exclusively. > After some more thought, I decided this was probably the better way to go. I can append data as needed. > > > My solution for the unit labels problem was to attach an attribute to the > Packet Table. The Unit attribute is an array of strings, one per column. > Indeed, it looks like I will need to do this for "column" names, data types, descriptions, etc. > > > Another important trick, for HDF5.net at least, you need to open the > Packet Table as a (H5D) dataset to attach/read an attribute. > Thanks. I have been out of the office for a few days, so I will be doing more today. > > > I’m not sure what you mean by (4) Packet Tables not having the concept of > a column? > The "regular" table has field names, field types, etc. This table seemed to lend itself more to the table concept. However, I can see (hope I can learn to use) the power of the attribute. I will send an update when I have success (!) or need help. Thanks, Michele > > > > > Scott > > > > *From:* Hdf-forum [mailto:hdf-forum-boun...@hdfgroup.org] *On Behalf Of > *Michele > De La Pena > *Sent:* Monday, October 22, 2012 5:54 PM > *To:* hdf-forum@hdfgroup.org > *Subject:* [Hdf-forum] Newbie questions regarding tables > > > > HI Folks, > > I am an HDF5 newbie, so please be patient. I have a few basic > questions after reading the tutorials and such. First, I will say that > I have telemetry data (timestamp with state information) which I need > to stream to an HDF file. The data nicely fits the model of a table. > > My Sys Admin has installed HDF5 version 1.9.131. > > My first question is regard to your table APIs. I see that an HDF > file can consist of the fundamental constructs of group and/or dataset. > However, it seems the table and packetTable are also fundamental in > that I do not have to package either of these tables inside of a group to > make a valid HDF file. (1) Is this the way these are intended to be used? > > My problem with the regular table is that during its creation, it does > not hand back an identifier so I cannot attach attributes directly to > the table. I would like the columns in the table to have "units" and > a "description" as meta-data for the table. I can put the regular > table and an attributes into a group (where the attributes > are attached to the group) which seems not too bad overall. > (2) Is this what one would ordinarily do for this issue? > (3) Maybe I made a mistake, but I cannot h5dump or h5stat the file I > have generated with a regular table. Is this expected? > > (4) As for the packet table, I can attach attributes, but the packet table > does not really have the concept of columns as far as I can tell. So > is it assumed that meta-data will be handled in the attributes dataset > which can attach to the packet table? > > Is it that I am just to bound by my conventional view of the world, and > HDF is more general. Can I make the packetTable actually anything > I want it to be via attributes? > > Thanks, > Michele > > -- > Michele D. De La Pena Scientific Software Engineer > Large Binocular Telescope Obs. email: mdelap...@lbto.org > 933 N. Cherry Avenue phone: 520-626-1402 > Tucson, AZ 85721-0065 cell: 520-419-8825 > > ------------------------------ > > Email addresses of ITT Exelis employees have changed from itt.com to > exelisinc.com. Please update your favorites and contact information to > reflect these changes. > > This e-mail and any files transmitted with it may be proprietary and are > intended solely for the use of the individual or entity to whom they are > addressed. If you have received this e-mail in error please notify the > sender. Please note that any views or opinions presented in this e-mail are > solely those of the author and do not necessarily represent those of Exelis > Inc. The recipient should check this e-mail and any attachments for the > presence of viruses. Exelis Inc. accepts no liability for any damage caused > by any virus transmitted by this e-mail. > > _______________________________________________ > Hdf-forum is for HDF software users discussion. > Hdf-forum@hdfgroup.org > http://mail.hdfgroup.org/mailman/listinfo/hdf-forum_hdfgroup.org > > -- Michele D. De La Pena Scientific Software Engineer Large Binocular Telescope Obs. email: mdelap...@lbto.org 933 N. Cherry Avenue phone: 520-626-1402 Tucson, AZ 85721-0065 cell: 520-419-8825
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