title: Combined hdf5 files into single dataset
body: <p>I have many hdf5 files each with a single dataset on them. I want to combine them into one dataset where the data is all in the same volume (each file is an image, I want one large timelapse image). </p>
  
  <p>I wrote a python script to extract the data as a numpy array, store them, then try to write that to a new h5 file. However, this approach will not work because the combined data uses more than the 32 GB of RAM that I have.</p>
  
  <p>I also tried using h5copy, the command line tool.</p>
  
  <pre><code>h5copy -i file1.h5 -o combined.h5 -s '/dataset' -d '/new_data/t1'
  h5copy -i file2.h5 -o combined.h5 -s '/dataset' -d '/new_data/t2'
  </code></pre>
  
  <p>Which works, but it results in many datasets within the new file instead of having all of the datasets in series.</p>