title: Does calling random.normal on an array of values add noise?
body: <p>I saw this pattern in someone's code:</p>
  
  <pre><code>import numpy as np
  # Create array
  xx = np.linspace(0.0, 100.0, num=100)
  # Add Noise
  xx = np.random.normal(xx)
  </code></pre>
  
  <p>and it seems to add some noise to each value of the array, but I can't find any documentation for this.  What's happening?  What determines the properties (i.e. scaling) of the noise?  Is the given value being treated as the mean (i.e. the <code>loc</code> parameter) of each sampling from the <code>normal</code> distribution?</p>
  
  <p>I'd also be very curious to know why this behavior doesn't seem to be covered in the documentation.</p>