title: Common elements of two numpy ndarrays
body: <p>I have a <code>numpy</code> <code>ndarray</code> named <code>arr</code> with shape (200,) and a tuple <code>tup</code> containing another <code>ndarray</code> with shape (ndarray(150,)). I want to create a new array containing only the elements common to both <code>ndarray</code>s.</p>