def __init__(self, module, learner = None):
LearningAgent.__init__(self, module, learner)
# exploration module (linear flat network)
self.explorationmodule = buildNetwork(self.indim, self.outdim, bias=False)
# state dependent exploration layer
self.explorationlayer = StateDependentLayer(self.outdim, self.explorationmodule, 'explore')
# add exploration layer to top of network through identity connection
out = self.module.outmodules.pop()
self.module.addOutputModule(self.explorationlayer)
self.module.addConnection(IdentityConnection(out, self.module['explore'], self.module))
self.module.sortModules()
# tell learner the new module
self.learner.setModule(self.module)
# add the log likelihood (loglh) to the dataset and link it to the others
self.history.addField('loglh', self.module.paramdim)
self.history.link.append('loglh')
self.loglh = None
# if this flag is set to True, random weights are drawn after each reward,
# effectively acting like the vanilla policy gradient alg.
self.actaspg = False
class StateDependentAgent(PolicyGradientAgent):
""" StateDependentAgent is a learning agent, that adds a GaussianLayer to its module and stores its
deterministic inputs (mu) in the dataset. It keeps the weights of the exploration network
constant for a whole episode which creates smooth trajectories rather than independent random
perturbations at each timestep. See "State-Dependent Exploration for Policy Gradient Methods",
ECML PKDD 2008.
"""
def __init__(self, module, learner = None):
LearningAgent.__init__(self, module, learner)
# exploration module (linear flat network)
self.explorationmodule = buildNetwork(self.indim, self.outdim, bias=False)
# state dependent exploration layer
self.explorationlayer = StateDependentLayer(self.outdim, self.explorationmodule, 'explore')
# add exploration layer to top of network through identity connection
out = self.module.outmodules.pop()
self.module.addOutputModule(self.explorationlayer)
self.module.addConnection(IdentityConnection(out, self.module['explore'], self.module))
self.module.sortModules()
# tell learner the new module
self.learner.setModule(self.module)
# add the log likelihood (loglh) to the dataset and link it to the others
self.history.addField('loglh', self.module.paramdim)
self.history.link.append('loglh')
self.loglh = None
# if this flag is set to True, random weights are drawn after each reward,
# effectively acting like the vanilla policy gradient alg.
self.actaspg = False
def newEpisode(self):
LearningAgent.newEpisode(self)
self.explorationlayer.drawRandomWeights()
def getAction(self):
self.explorationlayer.setState(self.lastobs)
action = PolicyGradientAgent.getAction(self)
return action
def giveReward(self, r):
PolicyGradientAgent.giveReward(self, r)
if self.actaspg:
self.explorationlayer.drawRandomWeights()