title: Array functions in numpy
body: <p>I have a numpy array:</p>
  
  <pre><code>a = np.arange(500).reshape(100,5)
  </code></pre>
  
  <p>I can normalize it using the function below:</p>
  
  <pre><code>def normalizer(X, mini, maxi):
      X_std = (X - X.min(axis=0)) / (X.max(axis=0) - X.min(axis=0))
      X_scaled = X_std * (maxi - mini) + mini
      return X_scaled
  
  normalized = normalizer(X, -1, +1)
  </code></pre>
  
  <p>Now, I want to denormalize it, I mean get original array.
   What function should I write?</p>
  
  <pre><code> def denormalizer():
  
  denormalized = denormalizer()
  </code></pre>