basics for HDF5 and LabVIEW

[faustina]

I'm trying to write 1394 data packets to a HDF5 file.  I'm very new to HDF5 but I have downloaded the LabVIEW HDF5 library from me.mtu.edu and HDFView from the HGF Group.  My first attempt at creating a file showed me I was only writing the last batch of data, according to HDFView.  I have GigiBytes of data to write.  I cannot find any documentation that would help me use the library at me.mtu.edu.  Their documentation link is no longer valid.  Does anyone have any advice on how to write large quantities of data to this type of file?

[DFGray]

I have not used this library but can point out one issue you may be having.  HDF5 buffers data in memory and only writes it when the chunk size is reached.  As such, using HDFView, it may appear that data has not been written, when in reality it has, since the data is not yet on disk.  If the library has a flush function (HDF5 does), use it after your write to confirm that it has occurred.  You don't want to normally do this because of performance issues.

[faustina]

I can write a single array to a file but not multiple arrays.  I don't understand what I'm doing wrong.  I think I'm doing it correctly but cannot seem to write to the file.  I'm sure my steps are correct:

1) create the file

2) create dataspace

3) create dataset

4) set the chunk size (maybe I'm doing this wrong?)

for each array:

1) get the current dataspace

2) extend the dataset

3) get new datspace

4) select the hyperslab

5) write data to new dataset

and finally

1) close everything

I'm using LabVIEW 2009 SP1 and HDF5 1.8.5 from http://ftp.hdfgroup.org/HDF5/release/obtain5.html.  I've enclosed my VI HDF5testA.  I've also enclosed 2 VIs I've modified.