title: Check if an array is a multiple of another array
body: <p>I'm creating a program to solve a planar system, and I'm stuck on detecting if the planes are coincident. AKA: I need to check if array A's elements are a multiple of array B's elements.
  This is what I have so far:</p>
  
  <pre><code>
  def coincident(one, two):
    div_ = one[0]/two[0]
  
    for v in zip(one[1:], two[1:]):
      if v[0]/v[1] != div_:
        return False
    return np.dot(one, two) != 0</code></pre>
  
  <p>It takes 2 arrays, currently no longer that 4 elements, and divides the first elements from them. Then it iterates through the rest of the elements and checks if the dividend is the same as 'div_'. The last line is to account for arrays with all zeros in them, it uses numpy to dot product and check if it's zero.</p>
  
  <p>This doesn't work very well, for some reason and it doesn't handle zeros well either (dividing by zero).</p>