title: loading EMNIST-letters dataset
body: <p>I have been trying to find a way to load the EMNIST-letters dataset but without much success. I have found interesting stuff in the structure and can't wrap my head around what is happening. Here is what I mean:</p>
  
  <p>I downloaded the .mat format <a href="https://www.nist.gov/itl/iad/image-group/emnist-dataset" rel="noreferrer">in here</a></p>
  
  <p>I can load the data using </p>
  
  <pre><code>import scipy.io
  mat = scipy.io.loadmat('letter_data.mat') # renamed for conveniance
  </code></pre>
  
  <p>it is a dictionnary with the keys as follow:</p>
  
  <pre><code>dict_keys(['__header__', '__version__', '__globals__', 'dataset'])
  </code></pre>
  
  <p>the only key with interest is dataset, which I havent been able to gather data from. printing the shape of it give this:</p>
  
  <pre><code>&gt;&gt;&gt;print(mat['dataset'].shape)
  (1, 1)
  </code></pre>
  
  <p>I dug deeper and deeper to find a shape that looks somewhat like a real dataset and came across this:</p>
  
  <pre><code>&gt;&gt;&gt;print(mat['dataset'][0][0][0][0][0][0].shape)
  (124800, 784)
  </code></pre>
  
  <p>which is exactly what I wanted but I cant find the labels nor the test data, I tried many things but cant seem to understand the structure of this dataset.</p>
  
  <p>If someone could tell me what is going on with this I would appreciate it</p>