def tvbatch(t, v):
  """
  Convenience method for paring x and y data for training and validation.

  Returns tuples pairing, e.g., the offsetting each block by one timestep
  with respect to x and y versions, such that at each timestep t,
  y[t] = x[t + 1].

  Note that here and elsewhere it has been my custom to identify training data
  with the variables x and y, and validation data with xx and yy. This seems
  marginally more parsimonious to me than something like "training_x," etc.

  Returns:
    x, y, xx, yy
  """
  x, y   = t[:,:-1], t[:,1:]
  xx, yy = v[:,:-1], v[:,1:]
  return x, y, xx, yy