title: Outer product in tensorflow
body: <p>In tensorflow, there are nice functions for entrywise and matrix multiplication, but after looking through the docs, I cannot find any internal function for taking an <em>outer product</em> of two tensors, i.e., making a bigger tensor by all possible products of elements of smaller tensors (like numpy.outer): </p>
  
  <pre><code>v_{i,j} = x_i*h_j
  </code></pre>
  
  <p>or</p>
  
  <pre><code>M_{ij,kl} = A_{ij}*B_{kl}
  </code></pre>
  
  <p>Does tensorflow have such a function? </p>