title: How to use the eigen decomposition in numpy?
body: <p>In the follow algorithm weights is a 2017x2017 symmetric matrix of rank 7.</p>
  <p>I'm trying to do something with the columns of the eigendecomposition however I can't even get them to sum back to the original matrix. neoweights1 = weights, but neoweights = something totally different. What's the error here?</p>
  <pre><code>w,v = np.linalg.eig(weights)
  
  neoweights1 = w2 * (v2 @ v2.T)
  neoweights = np.zeros((matsize,matsize))
  for i in range(7):
      neoweights += np.real(w2[i] * (v2[i] @ v2[i].T))
  </code></pre>