Daniel: What are the N-bit type and filter and types you are referring to?
Do you mean something I would write or are you talking about something in
HDF5?

Also can anyone explain how H5T_NATIVE_B8 is different from
H5T_NATIVE_UINT8.

On Thu, Feb 11, 2016 at 1:29 AM, Daniel Tetlow <[email protected]>
wrote:

> You could try making your dataset using an N-bit type based on a copy of
> an 8-bit type, and then using the N-bit filter. You can then end up
> handling each Boolean value as a byte in memory, but they’re stored more
> compactly on disk. Might even compress well too.
>
>
>
> Dan
>
>
>
>
>
> *From:* Hdf-forum [mailto:[email protected]] *On
> Behalf Of *[email protected]
> *Sent:* 10 February 2016 21:23
> *To:* HDF Users Discussion List
> *Subject:* Re: [Hdf-forum] Boolean values
>
>
>
> I don’t think the hdf Boolean is any different than an integer. If you
> create a Boolean dataset and query the type, it comes back that it’s an
> int. You can’t tell after the fact that the data was specified as Boolean.
>
>
>
> I suppose you can create a packed Boolean type, but you’ll have to do the
> grunt work of muxing and de-muxing the Booleans.
>
>
>
> Ultimately, I stuck my bools in separate sbytes.
>
>
>
>
>
> *From:* Hdf-forum [mailto:[email protected]
> <[email protected]>] *On Behalf Of *David
> *Sent:* Wednesday, February 10, 2016 4:12 PM
> *To:* HDF Users Discussion List
> *Subject:* [Hdf-forum] Boolean values
>
>
>
> Is there a way to read/write compact boolean or bitfield values? I see the
> bitfield types but I can't understand how it's different than writing ints.
> The API examples show hand packing/unpacking of the bits. How is
> H5T_NATIVE_B8 different from H5T_NATIVE_UINT8?
>
> Ideally I'd like 8-bit bools in memory packed into 1-bit bools on disk so
> it's easy to work with when loaded but stored compactly.
>
>
>
> Thanks,
>
> David
>
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