title: How to concatenate many vectors in one matrix (each vector is a column of the new matrix)
body: <p>I have for simplicity 4 vectors (type of numpy.ndarray) each of size 256 and I want to create a new matrix where each column correspond to each vector. So after concatenation I will have a 256 * 4 matrix </p>
  
  <p>I tried either using hstack or np.concatenate but I don't get the result I want..</p>
  
  <p>Thanks in advance</p>