Hi Frank,

> On Jun 15, 2017, at 4:39 PM, Frank Loeffler <[email protected]> wrote:
> 
> On Thu, Jun 15, 2017 at 09:21:40PM +0000, Elena Pourmal wrote:
>> This behavior is documented in H5Dwrite 
>> https://support.hdfgroup.org/HDF5/doc/RM/RM_H5D.html#Dataset-Write
>> 
>> (yep...confusing)
> 
> Hi Elena,
> 
> Thanks. I must have missed that.
It is hard to find. I had to think little-bit before I recalled where to find 
this info ;-)

> This is indeed confusing. I am currently also looking at the tutorial at
> 
> https://support.hdfgroup.org/HDF5/Tutor/rdwt.html
> 
> which states: "Note that H5S_ALL is passed in for the memory and file 
> dataspace parameters in the read and write calls. This indicates that the 
> entire dataspace of the dataset will be read or written to."
> 
> While this is technically correct (since in the examples both the memory and 
> the file dataspace are specified as H5S_ALL), this is indeed a confusing 
> statement. Maybe a note could be added that 'H5S_ALL' by itself does not 
> necessarily have that meaning, and the meaning of specifying H5S_ALL for one 
> dataspace indeed depends on the other data space.
> 
Thank you for suggestion! We definitely need to have a better explanation how 
selections and data spaces work. I entered JIRA report HDFFV-10229.

> In general, this is quite a confusing choice of definition for H5S_ALL. Is 
> there another define that does what I actually thought H5S_ALL does:
> simply selecting the entire available space, independent of whatever was 
> selected for the other data space? My best guess is: no, since I don't see 
> anything mentioned in H5Spublic.h. It would be a useful addition.
Noted.
> 
> There is of course the simple workaround of specifying a space for both, but 
> requiring a separate data space for a simple array just because the other 
> space has an offset seems a bit awkward.
Agree.

Thank you for reporting!

Elena
> 
> Frank
> 
> _______________________________________________
> 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

Reply via email to