title: keras layer that computes logarithms?
body: <p>I'd like to set up a Keras layer in which each node simply computes the logarithm of the corresponding node in the preceding layer.  I see from the Keras documentation that there is a "log" function in its backend module.  But somehow I'm not understanding how to use this.  </p>
  
  <p>Thanks in advance for any hints you can offer!</p>