title: sorting a numpy matrix on gpu
body: <p>I have a large matrix - <code>1045506 x 3</code> which I want to sort based on the 1st column. Since, it's a numpy matrix, I can use argsort to get the result</p>
  
  <p><code>mat_sorted = mat[mat[:,0].argsort()]</code></p>
  
  <p>It takes about <code>69ms</code> to complete this step which seems a little to high to me.</p>
  
  <p>My question is if there is a way to speed up the computation using the GPU? I was looking at some libraries like pycuda, theano but I'm finding it hard to understand the documentation. Specially, the part around passing numpy arrays and matrices to the gpu. Any pointers will be extremely helpful.</p>