<SYSTEM_TASK:>
Solve the following problem using Python, implementing the functions described below, one line at a time
<END_TASK>
<USER_TASK:>
Description:
 def compare(items, params, rank=False):
 """Generate a comparison outcome that follows Luce's axiom. This function samples an outcome for the comparison of a subset of items, from a model parametrized by ``params``. If ``rank`` is True, it returns a ranking over the items, otherwise it returns a single item. Parameters items : list Subset of items to compare. params : array_like Model parameters. rank : bool, optional If true, returns a ranking over the items instead of a single item. Returns ------- outcome : int or list of int The chosen item, or a ranking over ``items``. """

    probs = probabilities(items, params)
    if rank:
        return np.random.choice(items, size=len(items), replace=False, p=probs)
    else:
        return np.random.choice(items, p=probs)