def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
"*** YOUR CODE HERE ***"
currentIterationCounter = 1
for state in mdp.getStates():
self.values[state] = mdp.getReward(state, 'Stop', state)
while (currentIterationCounter != self.iterations):
newValues = util.Counter()
for state in mdp.getStates():
tempValues = util.Counter()
for action in mdp.getPossibleActions(state):
for newStateAndProb in mdp.getTransitionStatesAndProbs(state, action):
newState = newStateAndProb[0]
prob = newStateAndProb[1]
tempValues[action] += prob*(mdp.getReward(state, action, newState)+self.discount*self.values[newState])
newValues[state] = tempValues[tempValues.argMax()]
currentIterationCounter += 1
for state in mdp.getStates():
self.values[state] = newValues[state]
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
"*** YOUR CODE HERE ***"
allStates = mdp.getStates()
vPrimes = util.Counter() # A Counter is a dict with default 0
iteration = 0
while iteration < iterations:
for s in allStates:
if mdp.isTerminal(s):
vPrimes[s] = mdp.getReward(s, None, s);
else:
sreward = mdp.getReward(s, None, s)
vPrimes[s] = sreward + discount * self.utilOfBestAction(mdp, s )
for s in allStates:
self.values[s] = vPrimes[s]
iteration +=1
def __init__(self, mdp, discount=0.9, iterations=100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
iteration = 1
while iteration <= self.iterations:
updated_values = self.values.copy()
for possibleNextState in mdp.getStates():
if mdp.isTerminal(possibleNextState) == True:
for possibleAction in mdp.getPossibleActions(
possibleNextState):
possibleValue = 0
for possibleTransition in mdp.getTransitionStatesAndProbs(
possibleNextState, possibleAction):
#Following Bellman's equation
possibleValue += possibleTransition[1] * (
mdp.getReward(possibleNextState,
possibleAction,
possibleTransition[0]) +
discount * self.values[possibleTransition[0]])
updated_values[possibleNextState] = possibleValue
else:
maxStateValue = float("-inf")
for possibleAction in mdp.getPossibleActions(
possibleNextState):
possibleValue = 0
for possibleTransition in mdp.getTransitionStatesAndProbs(
possibleNextState, possibleAction):
#Following Bellman's equation
possibleValue += possibleTransition[1] * (
mdp.getReward(possibleNextState,
possibleAction,
possibleTransition[0]) +
discount * self.values[possibleTransition[0]])
if possibleValue > maxStateValue:
maxStateValue = possibleValue
updated_values[possibleNextState] = maxStateValue
self.values = updated_values
iteration += 1
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
# Write value iteration code here
"*** YOUR CODE HERE ***"
self.depth = 1
self.qTable = {}
self.vTable = {}
for state in mdp.getStates():
self.vTable[state] = 0
self.qTable[state] = {}
for action in mdp.getPossibleActions(state):
self.qTable[state][action] = 0
while self.depth < self.iterations + 1:
self.tempTable = {}
for state in mdp.getStates():
self.stateValue = 0
if not mdp.isTerminal(state):
self.stateValue = -9999
for action in mdp.getPossibleActions(state):
self.Qtotal = 0
for nextState,prob in mdp.getTransitionStatesAndProbs(state,action):
self.reward = mdp.getReward(state, action, nextState)
self.Qtotal += prob * (self.reward + self.discount * self.vTable[nextState])
#print "###state:",state,"Next",nextState,"reward:",self.reward,"Qtotal",self.Qtotal,"Value:",self.vTable[nextState]
self.qTable[state][action] = self.Qtotal
#print self.qTable[state][action]
self.stateValue = max(self.stateValue,self.qTable[state][action])
else:
self.tempTable[state] = 0
self.tempTable[state] = self.stateValue
self.vTable = self.tempTable
self.depth += 1
for state in mdp.getStates():
self.stateValue = -9999
for action in mdp.getPossibleActions(state):
self.Qtotal = 0
for nextState,prob in mdp.getTransitionStatesAndProbs(state,action):
self.reward = mdp.getReward(state, action, nextState)
self.Qtotal += prob * (self.reward + self.discount * self.vTable[nextState])
self.qTable[state][action] = self.Qtotal
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
temp = util.Counter() #to keep track of values while iterating
#use this for argmax
states = mdp.getStates()
ValueIterationAgent.policy = dict.fromkeys(states, '')
actionUtilities = {}
#initialize utility fn
for state in states:
if mdp.isTerminal(state):
self.values[state] = mdp.getReward(state)
temp[state] = mdp.getReward(state)
looper = 0
#returns list of tuples - state and
# Write value iteration code here
"""
U(s) = R(s) + Y * (max value after trying each action)(T(s, a, s') * U(s))
Do this for all states
Return policy
Handle case for no available actions
"""
#loop until we've hit the right number of iterations
while looper < self.iterations:
for state in states:
actionUtilities = {}
possibleActions = mdp.getPossibleActions(state)
#start new Bellman eqn - add reward for each state
if len(possibleActions) == 0: #terminal state
newUtility = 0
elif len(possibleActions) == 1: #1 possible action: exit
actionUtilities[possibleActions[0]] = self.computeQValueFromValues(state, possibleActions[0])
ValueIterationAgent.policy[state] = possibleActions[0]
newUtility = actionUtilities[possibleActions[0]]
else:
for action in possibleActions: #multiple possible actions; try them all
actionUtilities[action] = self.computeQValueFromValues(state, action) #get the utility for each action at the given state
ValueIterationAgent.policy[state] = max(actionUtilities, key=actionUtilities.get) #update the policy for this state
newUtility = actionUtilities[ValueIterationAgent.policy[state]]
temp[state] = newUtility
self.values = temp.copy()
looper = looper + 1
"*** YOUR CODE HERE ***"
def __init__(self, mdp, discount=0.9, iterations=100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
# Write value iteration code here
"*** YOUR CODE HERE ***"
oldCounter = util.Counter()
states = mdp.getStates()
while self.iterations > 0:
for state in states:
if self.mdp.isTerminal(state):
self.values[state] = 0
else:
actions = mdp.getPossibleActions(state)
# if len(actions) > 0:
# initialize maxAct by calculating the first action from the action list of the given state
firstAct = actions[0]
listOfNextStateAndProbPairs = mdp.getTransitionStatesAndProbs(
state, firstAct)
for pair in listOfNextStateAndProbPairs:
value = 0
for pair in listOfNextStateAndProbPairs:
(nextState, prob) = pair
reward = mdp.getReward(state, firstAct, nextState)
value = value + prob * (reward + self.discount *
(oldCounter[nextState]))
# compare and choose the best action value
maxAct = value
for action in actions:
listOfNextStateAndProbPairs = mdp.getTransitionStatesAndProbs(
state, action)
value = 0
for pair in listOfNextStateAndProbPairs:
(nextState, prob) = pair
reward = mdp.getReward(state, action, nextState)
value = value + prob * (reward + self.discount *
(oldCounter[nextState]))
maxAct = max(maxAct, value)
# update the state value for the given state
self.values[state] = maxAct
oldCounter = self.values.copy()
self.iterations = self.iterations - 1
def runValueIteration(self):
"*** YOUR CODE HERE ***"
mdp = self.mdp
values = self.values
discount = self.discount
predecessors = {}
for state in mdp.getStates():
preList = []
for preState in mdp.getStates():
for action in mdp.getPossibleActions(preState):
if state in [
pair[0]
for pair in mdp.getTransitionStatesAndProbs(
preState, action) if pair[1] > 0
]:
preList.append(preState)
break
predecessors[state] = preList
queue = util.PriorityQueue()
for s in mdp.getStates():
if not mdp.isTerminal(s):
actions = mdp.getPossibleActions(s)
realValue = max(
sum(prob * (mdp.getReward(s, action, nextState) +
(discount * values[nextState]))
for (nextState, prob
) in mdp.getTransitionStatesAndProbs(s, action))
for action in actions)
diff = abs(realValue - values[s])
queue.push(s, 0 - diff)
for _ in range(self.iterations):
if queue.isEmpty():
return
s = queue.pop()
if not mdp.isTerminal(s):
actions = mdp.getPossibleActions(s)
values[s] = max(
sum(prob * (mdp.getReward(s, action, nextState) +
(discount * values[nextState]))
for (nextState, prob
) in mdp.getTransitionStatesAndProbs(s, action))
for action in actions)
for p in predecessors[s]:
actions = mdp.getPossibleActions(p)
realValue = max(
sum(prob * (mdp.getReward(p, action, nextState) +
(discount * values[nextState]))
for (nextState, prob
) in mdp.getTransitionStatesAndProbs(p, action))
for action in actions)
diff = abs(realValue - values[p])
if diff > self.theta:
queue.update(p, 0 - diff)
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
# Write value iteration code here
"*** YOUR CODE HERE ***"
oldCounter = util.Counter()
states = mdp.getStates()
while self.iterations>0:
for state in states:
if self.mdp.isTerminal(state):
self.values[state] = 0
else:
actions = mdp.getPossibleActions(state)
# if len(actions) > 0:
# initialize maxAct by calculating the first action from the action list of the given state
firstAct = actions[0]
listOfNextStateAndProbPairs = mdp.getTransitionStatesAndProbs(state, firstAct)
for pair in listOfNextStateAndProbPairs:
value = 0
for pair in listOfNextStateAndProbPairs:
(nextState, prob) = pair
reward = mdp.getReward(state, firstAct, nextState)
value = value + prob * (reward + self.discount * (oldCounter[nextState]))
# compare and choose the best action value
maxAct = value
for action in actions:
listOfNextStateAndProbPairs = mdp.getTransitionStatesAndProbs(state, action)
value = 0
for pair in listOfNextStateAndProbPairs:
(nextState, prob) = pair
reward = mdp.getReward(state, action, nextState)
value = value + prob * (reward + self.discount * (oldCounter[nextState]))
maxAct = max(maxAct, value)
# update the state value for the given state
self.values[state] = maxAct
oldCounter = self.values.copy()
self.iterations = self.iterations - 1
def __init__(self, mdp, discount=0.9, iterations=100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
"*** YOUR CODE HERE ***"
#define a dictionary to store values in iterations for each state
self.valueRecord = {}
for state in mdp.getStates():
self.valueRecord[state] = []
for i in range(0, self.iterations + 1):
for state in mdp.getStates():
if i == 0 or mdp.isTerminal(state):
self.valueRecord[state].append(0)
continue
actions = mdp.getPossibleActions(state)
#store the current reward as value and return
if 'exit' in actions:
self.valueRecord[state].append(
mdp.getReward(
state, 'exit',
mdp.getTransitionStatesAndProbs(state,
'exit')[0][0]))
continue
max = float("-inf")
#find the action that maximize the value
for action in actions:
summax = 0
for (s,
p) in mdp.getTransitionStatesAndProbs(state, action):
summax += p * (
mdp.getReward(state, action, s) +
self.discount * self.valueRecord[s][i - 1])
if summax > max:
max = summax
self.valueRecord[state].append(max)
#store the final value we get from iteration into values
for k, v in self.valueRecord.items():
self.values[k] = v[iterations]
def __init__(self, mdp, discount=0.9, iterations=100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
self.actions = util.Counter()
tempValues = util.Counter()
# Write value iteration code here
for k in range(0, iterations):
for state in mdp.getStates():
maxAction = float("-inf")
for action in mdp.getPossibleActions(state):
total = 0
for nextState, prob in mdp.getTransitionStatesAndProbs(
state, action):
total += prob * (
self.values[nextState] * discount +
mdp.getReward(state, action, nextState))
maxAction = max(maxAction, total)
tempValues[state] = maxAction
for state in mdp.getStates():
if tempValues[state] > float("-inf"):
self.values[state] = tempValues[state]
for state in mdp.getStates():
maxAction = None
maxActionValue = float("-inf")
for action in mdp.getPossibleActions(state):
total = 0
for nextState, prob in mdp.getTransitionStatesAndProbs(
state, action):
total += prob * (self.values[nextState] * discount +
mdp.getReward(state, action, nextState))
if total > maxActionValue:
maxActionValue = total
maxAction = action
self.actions[state] = maxAction
def __init__(self, mdp, discount=0.9, iterations=200):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
self.q_values = {}
self.best_action = {}
# calculate utilities values
for i in range(self.iterations):
next_values = util.Counter()
for s in mdp.getStates():
updated = False
for a in mdp.getPossibleActions(s):
action_value = 0.0
for t in mdp.getTransitionStatesAndProbs(s, a):
r = mdp.getReward(s, a, t[0])
action_value += t[1] * (r +
discount * self.values[t[0]])
if not updated or action_value > next_values[s]:
next_values[s] = action_value
updated = True
self.values = next_values
# with the given utilities, calculate q-values
p = False
for s in mdp.getStates():
self.best_action[s] = None
max_action_value = -10000000
for a in mdp.getPossibleActions(s):
action_value = 0.0
for t in mdp.getTransitionStatesAndProbs(s, a):
r = mdp.getReward(s, a, t[0])
action_value += t[1] * (r + discount * self.values[t[0]])
self.q_values[(s, a)] = action_value
if action_value > max_action_value:
max_action_value = action_value
self.best_action[s] = a
def __init__(self, mdp, discount=0.9, iterations=100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
iteration_values = util.Counter()
for i in range(iterations):
for state in mdp.getStates():
max_action_value = -99999
max_action = None
actions = mdp.getPossibleActions(state)
if len(actions) == 0:
max_action_value = mdp.getReward(state, None, None)
max_action = None
max_state_prime = None
else:
for action in actions:
summation = 0
for state_prime, prob in mdp.getTransitionStatesAndProbs(
state, action):
if mdp.isTerminal(state_prime):
iteration_values[state] = mdp.getReward(
state, 'exit', 'TERMINAL_STATE')
else:
utility = self.values[state_prime]
summation += utility * prob
if summation > max_action_value:
max_action_value = summation
max_action = action
iteration_values[state] = mdp.getReward(
state, None, None) + discount * max_action_value
# Update at the end of each iteration
self.values = iteration_values.copy()
def __init__(self, mdp, discount=0.9, iterations=100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
self.tempvalues = util.Counter()
# Write value iteration code here
for i in range(0, self.iterations):
newVal = self.values.copy()
for state in mdp.getStates():
if not mdp.isTerminal(state):
#worst V value possible
maxV = float("-inf")
for action in mdp.getPossibleActions(state):
v = 0
#transitions = [newState, probability]
for transition in mdp.getTransitionStatesAndProbs(
state, action):
v = v + transition[1] * (
mdp.getReward(state, action, transition[0]) +
discount * self.values[transition[0]])
if v > maxV:
maxV = v
newVal[state] = maxV
else:
#state is terminal
for action in mdp.getPossibleActions(state):
v = 0
for transition in mdp.getTransitionStatesAndProbs(
state, action):
v = v + transition[1] * (
mdp.getReward(state, action, transition[0]) +
discount * self.values[transition[0]])
newVal[state] = v
#update whole V values
self.values = newVal
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
for i in range(0,iterations):
b = self.values.copy()
#print ('b',b)
#print ('all',mdp.getStates())
for s in mdp.getStates():
if s == 'TERMINAL_STATE':
self.values[s]= 0
else:
#print ('s',s)
qlist = []
for a in mdp.getPossibleActions(s):
if a =='exit':
qlist.append(mdp.getReward(s,a,(mdp.getTransitionStatesAndProbs(s,a))))
else:
#print('a',a)
spsum = 0
for sp in mdp.getTransitionStatesAndProbs(s,a):
#print('sp',sp)
#print(mdp.getReward(s,a,sp[0]))
spsum =spsum+ (sp[1]*(mdp.getReward(s,a,sp[0])+self.discount*b[sp[0]]))
#print ('spsum',spsum)
#print('i',i)
qlist.append(spsum)
#print qlist
self.values[s] = max(qlist)
while len(qlist) > 0 : qlist.pop()
# Write value iteration code here
"*** YOUR CODE HERE ***"
def __init__(self, mdp, discount=0.9, iterations=100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.utilities = {}
self.qvalues = {}
states = mdp.getStates()
for state in states:
self.utilities[state] = 0
self.qvalues[state] = util.Counter()
for i in range(iterations):
newUtilities = {}
for state in states:
if self.mdp.isTerminal(state):
continue
childQs = []
for action in mdp.getPossibleActions(state):
q_value = 0
for transition in mdp.getTransitionStatesAndProbs(
state, action):
q_value += transition[1]*(mdp.getReward(state,action,transition[0]) + \
discount*self.utilities[transition[0]])
childQs.append(q_value)
newUtilities[state] = max(childQs)
self.utilities.update(newUtilities)
""" q-values are a dictionary from states to dictionaries of action => qvalue mappings"""
for state in states:
for action in mdp.getPossibleActions(state):
q_value = 0
for transition in mdp.getTransitionStatesAndProbs(
state, action):
q_value += transition[1]*(mdp.getReward(state,action,transition[0]) + \
discount*self.utilities[transition[0]])
self.qvalues[state][action] = q_value
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
"*** YOUR CODE HERE ***"
for i in range(iterations):
nextValues = util.Counter()
for state in mdp.getStates():
rewardsPossible = util.Counter()
for action in mdp.getPossibleActions(state):
nextPossible = size(mdp.getTransitionStatesAndProbs(state, action))[1]
newRewards = util.Counter()
for tmpState in range(nextPossible):
nextState = mdp.getTransitionStatesAndProbs(state, action)[tmpState][0]
prob = mdp.getTransitionStatesAndProbs(state, action)[tmpState][1]
rewards = mdp.getReward(state, action, tmpState)
newRewards[tmpState] = prob * (rewards + self.discount * self.values[nextState])
rewardsPossible[action] = newRewards.totalCount()
nextValues[state] = rewardsPossible[rewardsPossible.argMax()]
self.values = nextValues
def __init__(self, mdp, discount=0.9, iterations=100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
while self.iterations > 0:
prev_values = self.values.copy()
for state in mdp.getStates():
actions = mdp.getPossibleActions(state)
if not actions:
continue
self.values[state] = max([sum([prob*(mdp.getReward(state, act, state1) + discount*prev_values[state1])
for state1, prob in mdp.getTransitionStatesAndProbs(state, act)])
for act in actions])
self.iterations -= 1
def computeQValueFromValues(self, state, action):
"""
Compute the Q-value of action in state from the
value function stored in self.values.
"""
"*** YOUR CODE HERE ***"
# get the discount
discount = self.discount
# get the values
values = self.values
# get the mdp
mdp = self.mdp
# set initial q value
qv = 0
#
tStatesAndProbs = mdp.getTransitionStatesAndProbs(state, action)
# keep track of pairs seen so far
j = 0
while j < len(tStatesAndProbs):
# extract tState and Prob from this member of the list
tState = tStatesAndProbs[j][0]
prob = tStatesAndProbs[j][1]
# calcuate the qv the same we we calculated v above
qv = qv + ((discount * values[tState]) + mdp.getReward(state, action, tState)) * prob
# increment
j = j + 1
return qv
def __init__(self, mdp, discount=0.9, iterations=100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
# Write value iteration code here
"*** YOUR CODE HERE ***"
for i in range(self.iterations):
temp = self.values.copy()
for item in mdp.getStates():
value_list = []
if mdp.isTerminal(item):
self.values[item] = 0
continue
for k in mdp.getPossibleActions(item):
sum_value = 0
for x in mdp.getTransitionStatesAndProbs(item, k):
reward_next_state = mdp.getReward(item, k, x[0])
sum_value += x[1] * (reward_next_state +
self.discount * temp[x[0]])
value_list.append(sum_value)
self.values[item] = max(value_list)
def __init__(self, mdp, discount=0.9, iterations=100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
for k in range(self.iterations):
self.values_old = self.values.copy()
for s in mdp.getStates():
if not self.mdp.isTerminal(s):
self.values[s] = max(
[
sum(
[
T * (mdp.getReward(s, a, sp) + self.discount * self.values_old[sp])
for (sp, T) in mdp.getTransitionStatesAndProbs(s, a)
]
)
for a in mdp.getPossibleActions(s)
]
)
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
"*** YOUR CODE HERE ***"
for s in mdp.getStates():
self.values[s] = 0
"for a in mdp.getPossibleActions(s):"
"for ac in mdp.getTransitionStatesAndProbs(s,a):"
" print ac[0]"
"print ac[1]"
"copy_value = self.values.copy()"
"for c in mdp.getStates():"
" print copy_value[c]"
i=0
"self.states = mdp.getStates()"
while i < iterations:
copy_value = self.values.copy()
for s in mdp.getStates():
if not mdp.isTerminal(s):
self.values[s] = mdp.getReward(s,'north',s) + discount * max([sum([copy_value[s1] * p for (s1,p) in mdp.getTransitionStatesAndProbs(s,a)]) for a in mdp.getPossibleActions(s)])
i = i + 1
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
# Write value iteration code here
"*** YOUR CODE HERE ***"
for _ in range(iterations):
updateBatch = self.values.copy()
for state in mdp.getStates():
self.values[state] = max([
sum([prob*(mdp.getReward(state, action, transitionState) + discount*updateBatch[transitionState])
for transitionState, prob
in mdp.getTransitionStatesAndProbs(state, action)
if prob != 0])
for action in mdp.getPossibleActions(state)] or [0])
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
"*** YOUR CODE HERE ***"
for n in range(iterations):
V = self.values.copy()
for s in mdp.getStates():
action_values = []
for a in mdp.getPossibleActions(s):
action_value = 0
for s_, P in mdp.getTransitionStatesAndProbs(s, a):
action_value += P * (mdp.getReward(s, a, s_) + discount * V[s_])
action_values.append(action_value)
self.values[s] = max(action_values or [0])
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
"*** YOUR CODE HERE ***"
for i in range(0, iterations):
preValues = self.values.copy()
for state in mdp.getStates():
curValue = util.Counter()
for action in mdp.getPossibleActions(state):
for (nextState, prob) in mdp.getTransitionStatesAndProbs(state, action):
curValue[action] += prob*(mdp.getReward(state, action, nextState)+discount*preValues[nextState])
self.values[state] = curValue[curValue.argMax()]
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
# Write value iteration code here
while self.iterations > 0:
junk = self.values.copy()
for state in self.mdp.getStates():
garbage = {}
for action in mdp.getPossibleActions(state):
garbage[action] = 0
for (nextState, prob) in self.mdp.getTransitionStatesAndProbs(state, action):
garbage[action] += prob * (mdp.getReward(state, action, nextState) + self.discount * junk[nextState])
try:
self.values[state] = max(garbage.values())
except ValueError:
self.values[state] = 0
self.iterations -= 1
def __init__(self, mdp, discount=0.9, iterations=100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter(
) # A Counter is a dict with default values as 0
"*** YOUR CODE HERE ***"
states = mdp.getStates()
for k in range(0, iterations):
for state in states:
actions = []
for action in mdp.getPossibleActions(state):
trans_prob = mdp.getTransitionStatesAndProbs(state, action)
actions.append(
sum(self.values[tp[0], k - 1] * tp[1]
for tp in trans_prob))
if actions:
max_prob = max(actions)
else:
max_prob = 0
self.values[state,
k] = mdp.getReward(state) + discount * max_prob
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
"*** YOUR CODE HERE ***"
for i in range(iterations):
newValues=util.Counter()
for state in mdp.getStates():
values=[]
for action in mdp.getPossibleActions(state):
qvalue=sum([(discount*self.values[newState]+mdp.getReward(state,action,newState))*prob for newState,prob in mdp.getTransitionStatesAndProbs(state,action)])
values.append(qvalue)
if len(values)>0:
newValues[state]=max(values)
for state in self.values:
self.values[state]=newValues[state]
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
for i in range(iterations):
lastValues = copy.deepcopy(self.values)
for s in mdp.getStates():
aCounter = util.Counter()
for a in mdp.getPossibleActions(s):
for s2 in mdp.getStates():
aCounter[a] += self.T(s,a,s2) * (mdp.getReward(s,a,s2) + discount*lastValues[s2])
self.values[s] = aCounter[aCounter.argMax()]
def __init__(self, mdp, discount=0.9, iterations=100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
# Write value iteration code here
for k in range(1, iterations + 1):
values = copy(self.values)
for state in mdp.getStates():
actions = mdp.getPossibleActions(state)
if len(actions) > 0:
self.values[state] = max([
sum([
prob * (mdp.getReward(state, action, next) +
discount * values[next])
for next, prob in mdp.getTransitionStatesAndProbs(
state, action)
]) for action in mdp.getPossibleActions(state)
])
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
for i in range(iterations):
nextValues = util.Counter()
for state in mdp.getStates():
if mdp.isTerminal(state): continue
first = True
for action in mdp.getPossibleActions(state):
qValue = 0
for (nextState, prob) in mdp.getTransitionStatesAndProbs(state, action):
reward = mdp.getReward(state, action, nextState)
qValue += prob * (reward + discount*self.values[nextState])
if first:
maxQValue = qValue
first = False
elif qValue > maxQValue:
maxQValue = qValue
nextValues[state] = maxQValue
self.values = nextValues
def __init__(self, mdp, discount=0.9, iterations=100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
"*** YOUR CODE HERE ***"
for i in range(iterations):
newValues = util.Counter()
for state in mdp.getStates():
values = []
for action in mdp.getPossibleActions(state):
qvalue = sum([
(discount * self.values[newState] +
mdp.getReward(state, action, newState)) * prob
for newState, prob in mdp.getTransitionStatesAndProbs(
state, action)
])
values.append(qvalue)
if len(values) > 0:
newValues[state] = max(values)
for state in self.values:
self.values[state] = newValues[state]
def __init__(self, mdp, discount=0.9, iterations=100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
# Write value iteration code here
"*** YOUR CODE HERE ***"
# keep track of the number of iterations we have done so far
i = 0
# final output value
v = 0
# get all the states
states = mdp.getStates()
# for each of the specified iterations:
while i < iterations:
# save the current self.values
oldSV = self.values.copy()
# increment our variable for number of iterations
i = i + 1
# for each of the states,
for s in states:
# get the value at this state
v = util.Counter()
# look at all possible actions from that state
actions = mdp.getPossibleActions(s)
# for each state action pair ...
for a in actions:
# get the transition states and the probablilities of
# reaching those states
tStatesAndProbs = mdp.getTransitionStatesAndProbs(s, a)
# keep track of the number of pairs we have seen so far
j = 0
# print tStatesAndProbs
# for each pair in tStatesAndProbs,
while j < len(tStatesAndProbs):
# extract tState and Prob from this member of the list
tState = tStatesAndProbs[j][0]
prob = tStatesAndProbs[j][1]
# set the value associated with that move
# make sure to account for prob and discount
v[a] = v[a] + (mdp.getReward(s, a, tState) +
discount * oldSV[tState]) * prob
# increment
j = j + 1
# return
self.values[s] = v[v.argMax()]
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
# Write value iteration code here
"*** YOUR CODE HERE ***"
temp = util.Counter()
for i in xrange(iterations):
temp = self.values.copy()
for j in mdp.getStates():
vlist = []
actions = mdp.getPossibleActions(j)
if not mdp.isTerminal(j):
for k in actions:
tran = mdp.getTransitionStatesAndProbs(j, k)
val = 0
for m in tran:
val += m[1] * (mdp.getReward(j, k, m[0]) + self.discount * temp[m[0]])
vlist.append(val)
self.values[j] = max(vlist)
def __init__(self, mdp, discount=0.9, iterations=100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
# Write value iteration code here
"*** YOUR CODE HERE ***"
for i in range(iterations):
oldv = self.values.copy()
for s in mdp.getStates():
if (mdp.isTerminal(s)):
self.values[s] = 0
continue
maxu = None
for a in mdp.getPossibleActions(s):
eu = 0
for (sp, p) in mdp.getTransitionStatesAndProbs(s, a):
r = mdp.getReward(s, a, sp)
r += self.discount * oldv[sp]
eu += p * r
if (maxu is None or eu > maxu): maxu = eu
self.values[s] = maxu
def __init__(self, mdp, discount=0.9, iterations=100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
for _ in range(0, iterations):
self.newValues = util.Counter()
for st in mdp.getStates():
if len(mdp.getPossibleActions(st)) != 0:
maxV = -sys.maxint
for act in mdp.getPossibleActions(st):
newV = 0
for tst, prob in mdp.getTransitionStatesAndProbs(
st, act):
r = mdp.getReward(st, act, tst)
newV += prob * (r + discount * self.values[tst])
if newV > maxV: maxV = newV
self.newValues[st] = maxV
else:
self.newValues[st] = self.values[st]
self.values = self.newValues
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter()
for i in range(iterations): # running the alg on the indicated number of iterations
y = self.values.copy() #V sub k-1
for state in mdp.getStates():
actions = util.Counter()
if mdp.isTerminal(state) == False:
for possibleActions in mdp.getPossibleActions(state):
for transitionState, prob in mdp.getTransitionStatesAndProbs(state, possibleActions):
value_iteration = prob * (mdp.getReward(state, possibleActions, transitionState) + (discount* y[transitionState]))
actions[possibleActions] += value_iteration
self.values[state] = actions[actions.argMax()]
def __init__(self, mdp, discount=0.9, iterations=100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
# Write value iteration code here
"*** YOUR CODE HERE ***"
for i in range(self.iterations): # run the indicated iterations
valuesCopy = self.values.copy() # a copy of the Counter
for state in self.mdp.getStates():
tmpValues = util.Counter()
for action in self.mdp.getPossibleActions(state):
for nextState, prob in self.mdp.getTransitionStatesAndProbs(
state, action):
tmpValues[action] += prob * (
mdp.getReward(state, action, nextState) +
self.discount * valuesCopy[nextState])
self.values[state] = tmpValues[
tmpValues.argMax()] # return highest value
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
"*** YOUR CODE HERE ***"
# OUR CODE HERE
#Note: I think we should use the util.Counter thing?
for times in range(0, iterations):
#values from previous iteration so we don't update over them while iterating
prevVals = self.values.copy()
#iterate through all states
for state in mdp.getStates():
#will store the action-value for the iteration
value = util.Counter()
for action in mdp.getPossibleActions(state):
for transitionState, probability in mdp.getTransitionStatesAndProbs(state, action):
#expected value, probability * reward for the state with the discount * reward
value[action] += probability * (mdp.getReward( state, action, transitionState) + discount * prevVals[transitionState])
#update the values to the new value from the iteration
#the .argMax() function returns the one with the largest value
self.values[state] = value[value.argMax()]
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
states = mdp.getStates()
for i in range(iterations):
lastValues = self.values.copy()
for s in states:
actions = mdp.getPossibleActions(s)
if not actions:
continue
values = []
for a in actions:
sum = 0
for s2, p in mdp.getTransitionStatesAndProbs(s,a):
sum += p * lastValues[s2]
values.append(mdp.getReward(s,None,None) + self.discount*sum)
self.values[s] = max(values)
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
helper_vector = util.Counter() # Copy of vectors to be used for batch updating
for i in range(self.iterations):
for state in mdp.getStates():
if mdp.isTerminal(state):
continue
if mdp.getPossibleActions(state):
helper_vector[state] = sum([transition[1]*(mdp.getReward(state,mdp.getPossibleActions(state)[0],transition[0])+self.discount*self.values[transition[0]])
for transition in mdp.getTransitionStatesAndProbs(state, mdp.getPossibleActions(state)[0])] )
for action in mdp.getPossibleActions(state):
helper_vector[state] = max(helper_vector[state],sum([ transition[1]*(mdp.getReward(state, action, transition[0])+self.discount*self.values[transition[0]])
for transition in mdp.getTransitionStatesAndProbs(state, action)] ))
for state in helper_vector:
self.values[state] = helper_vector[state]
def computeActionFromValues(self, state):
"""
The policy is the best action in the given state
according to the values currently stored in self.values.
You may break ties any way you see fit. Note that if
there are no legal actions, which is the case at the
terminal state, you should return None.
"""
"*** YOUR CODE HERE ***"
import random
mdp = self.mdp
possibleActions = mdp.getPossibleActions(state)
valuesForAction = util.Counter()
if (mdp.isTerminal(state)):
return None
for action in possibleActions:
tp = mdp.getTransitionStatesAndProbs(state, action)
sum = 0
for i in range(len(tp)):
nextState, prob = tp[i]
sum = sum + prob * (mdp.getReward(state, action, nextState) +
self.discount * self.values[nextState])
valuesForAction[action] = sum
if (valuesForAction.totalCount() == 0):
return possibleActions[0]
return valuesForAction.argMax()
def computeActionFromValues(self, state):
"""
The policy is the best action in the given state
according to the values currently stored in self.values.
You may break ties any way you see fit. Note that if
there are no legal actions, which is the case at the
terminal state, you should return None.
"""
"*** YOUR CODE HERE ***"
mdp = self.mdp
actions = mdp.getPossibleActions(state)
if len(actions) == 0:
return "stop"
best_action = (-99999999999999, None)
for a in actions:
transitions = mdp.getTransitionStatesAndProbs(state,a)
value_of_action = 0
for y in transitions:
prob = y[1]
new_state = y[0]
reward = mdp.getReward(state,a,new_state)
next = self.values[new_state]
val = prob*(reward + self.discount*next)
value_of_action += val
if value_of_action >= best_action[0]:
best_action = (value_of_action, a)
return best_action[1]
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
"*** YOUR CODE HERE ***"
# Init : Not required
# Value iteration
for i in range(iterations):
old_values = self.values.copy()
for state in mdp.getStates():
value_state_action = []
for action in mdp.getPossibleActions(state):
val = 0
transition = mdp.getTransitionStatesAndProbs(state,action)
for sstate,prob_s_a_ss in transition:
val += prob_s_a_ss*(mdp.getReward(state,action,sstate) + discount*old_values[sstate])
value_state_action.append(val)
if value_state_action : self.values[state] = max(value_state_action)
def __init__(self, mdp, discount=0.9, iterations=100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
# Write value iteration code here
for i in xrange(iterations):
new_values = self.values.copy()
for state in mdp.getStates():
actions = mdp.getPossibleActions(state)
qValues = []
for action in actions:
probs = mdp.getTransitionStatesAndProbs(state, action)
qvs = [
p * (self.values[nextState] * discount +
mdp.getReward(state, action, nextState))
for nextState, p in probs
]
qValues.append(sum(qvs))
if len(qValues) > 0:
new_values[state] = max(qValues)
else:
new_values[state] = 0
self.values = new_values
def __init__(self, mdp, discount=0.9, iterations=100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
while self.iterations > 0:
prev_values = self.values.copy()
for state in mdp.getStates():
actions = mdp.getPossibleActions(state)
if not actions:
continue
self.values[state] = max([
sum([
prob * (mdp.getReward(state, act, state1) +
discount * prev_values[state1])
for state1, prob in mdp.getTransitionStatesAndProbs(
state, act)
]) for act in actions
])
self.iterations -= 1
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
"*** YOUR CODE HERE ***"
for times in range(iterations):
V = self.values.copy()
for state in mdp.getStates():
action_values = util.Counter()
for action in mdp.getPossibleActions(state):
for trans_state, prob in mdp.getTransitionStatesAndProbs(state, action):
action_values[action] += prob * (mdp.getReward( state, action, trans_state) + discount * V[trans_state])
self.values[state] = action_values[action_values.argMax()]
def __init__(self, mdp, discount=0.9, iterations=100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
newValues = util.Counter()
# Write value iteration code here
"*** YOUR CODE HERE ***"
allStates = mdp.getStates()
for i in range(iterations):
for s in allStates:
if mdp.isTerminal(s): continue
mx = float("-inf")
for a in mdp.getPossibleActions(s):
score = 0
for (sp, tp) in mdp.getTransitionStatesAndProbs(s, a):
score += tp * (mdp.getReward(s, a, sp) +
self.discount * self.values[sp])
if score > mx:
mx = score
newValues[s] = mx
self.values = newValues.copy()
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
# Write value iteration code here
"*** YOUR CODE HERE ***"
#states = mdp.getStates()
#values = {state: 0 for state in states}
for i in range(iterations):
previous = self.values.copy()
for state in mdp.getStates():
possibleActions = mdp.getPossibleActions(state)
if len(possibleActions) == 0: continue
results = []
for action in possibleActions:
total = 0
for (nextState, prob) in mdp.getTransitionStatesAndProbs(state,action):
total += (prob * previous[nextState])
results.append(total)
self.values[state] = mdp.getReward(state) + (discount * max(results))
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
self.qvalues = util.Counter()
self.bestact = util.Counter()
"*** YOUR CODE HERE ***"
states = mdp.getStates()
for i in range(iterations):
v = util.Counter()
for state in states:
if mdp.isTerminal(state):
continue
value = {action: sum(prob * (mdp.getReward(state,action,next_state) + discount*self.values[next_state])
for next_state, prob in mdp.getTransitionStatesAndProbs(state, action))
for action in mdp.getPossibleActions(state)}
self.bestact[state] = max(value, key=value.get)
v[state] = value[self.bestact[state]]
for action in value.keys():
self.qvalues[state,action] = value[action]
self.values = v.copy()
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
mdpStates = mdp.getStates()
for iteration in xrange(iterations):
newValues = util.Counter()
for state in mdpStates:
if self.mdp.isTerminal(state):
continue
actionValues = -sys.maxint - 1
for action in mdp.getPossibleActions(state):
sum = 0
for transitionState, prob in mdp.getTransitionStatesAndProbs(state, action):
sum += prob*(mdp.getReward(state, action, transitionState) + discount * self.values[transitionState])
if sum > actionValues:
actionValues = sum
newValues[state] = actionValues
self.values = newValues
def computeQValueFromValues(self, state, action):
"""
Compute the Q-value of action in state from the
value function stored in self.values.
"""
"*** YOUR CODE HERE ***"
# get the discount
discount = self.discount
# get the values
values = self.values
# get the mdp
mdp = self.mdp
# set initial q value
qv = 0
#
tStatesAndProbs = mdp.getTransitionStatesAndProbs(state, action)
# keep track of pairs seen so far
j = 0
while j < len(tStatesAndProbs):
# extract tState and Prob from this member of the list
tState = tStatesAndProbs[j][0]
prob = tStatesAndProbs[j][1]
# calcuate the qv the same we we calculated v above
qv = qv + ((discount * values[tState]) +
mdp.getReward(state, action, tState)) * prob
# increment
j = j + 1
return qv
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
self.policy = util.Counter()
oldValues = util.Counter()
states = mdp.getStates()
for x in xrange(0,iterations):
for state in states:
possibleActions = mdp.getPossibleActions(state)
qValues = util.Counter()
for action in possibleActions:
qValue = 0;
for nextState, prob in mdp.getTransitionStatesAndProbs(state,action):
qValue += prob*(mdp.getReward(state, action, nextState)+discount*oldValues[nextState])
qValues[action] = qValue
bestAction = qValues.argMax()
self.values[state] = qValues[bestAction]
for value in self.values:
oldValues[value] = self.values[value]
def computeQValueFromValues(self, state, action):
"""
Compute the Q-value of action in state from the
value function stored in self.values.
"""
"*** YOUR CODE HERE ***"
mdp = self.mdp
discount = self.discount
iterations = self.iterations
values = self.values
#states = mdp.getStates()
#print('state is :', state)
qValues = []
sum = 0
for item in mdp.getTransitionStatesAndProbs(
state, action
): #'mdp.getTransitionStatesAndProbs :', [((0, 1), 1.0), ((0, 0), 0.0), ((0, 2), 0.0)]
resultState = item[0]
prob = item[1]
sum += prob * (mdp.getReward(state, action, resultState) +
discount * values[resultState])
return sum
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.utilities = {}
self.qvalues = {}
states = mdp.getStates()
for state in states:
self.utilities[state] = 0
self.qvalues[state] = util.Counter()
for i in range(iterations):
newUtilities = {}
for state in states:
if self.mdp.isTerminal(state):
continue
childQs = []
for action in mdp.getPossibleActions(state):
q_value = 0
for transition in mdp.getTransitionStatesAndProbs(state,action):
q_value += transition[1]*(mdp.getReward(state,action,transition[0]) + \
discount*self.utilities[transition[0]])
childQs.append(q_value)
newUtilities[state] = max(childQs)
self.utilities.update(newUtilities)
""" q-values are a dictionary from states to dictionaries of action => qvalue mappings"""
for state in states:
for action in mdp.getPossibleActions(state):
q_value = 0
for transition in mdp.getTransitionStatesAndProbs(state,action):
q_value += transition[1]*(mdp.getReward(state,action,transition[0]) + \
discount*self.utilities[transition[0]])
self.qvalues[state][action] = q_value
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
"*** YOUR CODE HERE ***"
## get dict of transitions for all (state, action, destination):
self.T = dict()
self.R = dict()
self.D = dict()
for state in self.mdp.getStates():
if self.mdp.isTerminal(state):
continue
actions = self.mdp.getPossibleActions(state)
for action in actions:
for (destination, prob ) in mdp.getTransitionStatesAndProbs(state, action):
self.T[(state, action, destination)] = prob
self.R[(state, action, destination)] = mdp.getReward(state, action, destination)
if (state,action) not in self.D:
self.D[(state, action)] = [destination]
else:
self.D[(state, action)] += [destination]
#print "----------T:\n", self.T, '\n-------R:\n', self.R, '\n------D:\n', self.D
for _ in range(iterations):
#print "\n----------SELF.VALUES\n", self.values
copyVals = util.Counter()
for state in self.mdp.getStates():
if self.mdp.isTerminal(state):
continue
actions = self.mdp.getPossibleActions(state)
bestVals = []
#print state , mdp.getPossibleActions(state)
for action in actions:
#for dest in self.D[state,action]:
#print "(state,action,dest):", (state, action, dest) , "T:", self.T[(state, action, dest)], "R:",self.R[(state, action, dest)], "k_val:", self.values[dest]
#bestVals += [ sum( [ self.T[state, action, dest] * ( self.R[state, action, dest] + self.discount*self.values[dest] ) ] ) ]
bestVals += [self.getQValue(state,action)]
#bestVals += [ sum( [ T[state, action, dest] * ( R[state, action, dest] + self.discount*self.values[state] )
# for dest in D[state,action] ] ) ]
#print "state", state, "bestvals", bestVals
copyVals[state] = max(bestVals)
#self.values[state] = max(bestVals)
self.values = copyVals.copy()
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
# Write value iteration code here
"*** YOUR CODE HERE ***"
# keep track of the number of iterations we have done so far
i = 0
# final output value
v = 0
# get all the states
states = mdp.getStates()
# for each of the specified iterations:
while i < iterations:
# save the current self.values
oldSV = self.values.copy()
# increment our variable for number of iterations
i = i + 1
# for each of the states,
for s in states:
# get the value at this state
v = util.Counter()
# look at all possible actions from that state
actions = mdp.getPossibleActions(s)
# for each state action pair ...
for a in actions:
# get the transition states and the probablilities of
# reaching those states
tStatesAndProbs = mdp.getTransitionStatesAndProbs(s, a)
# keep track of the number of pairs we have seen so far
j = 0
# print tStatesAndProbs
# for each pair in tStatesAndProbs,
while j < len(tStatesAndProbs):
# extract tState and Prob from this member of the list
tState = tStatesAndProbs[j][0]
prob = tStatesAndProbs[j][1]
# set the value associated with that move
# make sure to account for prob and discount
v[a] = v[a] + (mdp.getReward(s, a, tState) + discount * oldSV[tState]) * prob
# increment
j = j + 1
# return
self.values[s] = v[v.argMax()]
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
self.actions = util.Counter()
tempValues = util.Counter()
# Write value iteration code here
for k in range(0,iterations):
for state in mdp.getStates():
maxAction = float("-inf")
for action in mdp.getPossibleActions(state):
total = 0
for nextState, prob in mdp.getTransitionStatesAndProbs(state, action):
total += prob * (self.values[nextState] * discount + mdp.getReward(state, action, nextState))
maxAction = max(maxAction, total)
tempValues[state] = maxAction
for state in mdp.getStates():
if tempValues[state] > float("-inf"):
self.values[state] = tempValues[state]
for state in mdp.getStates():
maxAction = None
maxActionValue = float("-inf")
for action in mdp.getPossibleActions(state):
total = 0
for nextState, prob in mdp.getTransitionStatesAndProbs(state, action):
total += prob * (self.values[nextState] * discount + mdp.getReward(state, action, nextState))
if total > maxActionValue:
maxActionValue = total
maxAction = action
self.actions[state] = maxAction
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
"*** YOUR CODE HERE ***"
"value at each state"
self.V = util.Counter()
self.tempV = util.Counter()
"Q for each state,action pair"
self.Q = util.Counter()
"policy for each state = best action to take"
self.P = util.Counter()
gamma = self.discount
for iter in range(1,self.iterations+1):
for state in mdp.getStates():
"There is a Q for each (state,action) pair, so index this by state and keep a list of all actions"
self.Q[state] = util.Counter()
"Cycle through each possible action for the given state"
for action in mdp.getPossibleActions(state):
for neighborStateAndTransitionProb in mdp.getTransitionStatesAndProbs(state,action):
[neighborState, T_s_a_sp] = neighborStateAndTransitionProb
"Compute the Q values for this state and the available actions"
R_s_a_sp = mdp.getReward(state,action,neighborState)
self.Q[state][action] += T_s_a_sp*(R_s_a_sp+gamma*self.V[neighborState])
"As long as there were actions at this state, find the one that produces the largest Q value"
if len(self.Q[state]) > 0:
maxQstate = -1000000
maxQAction = None
for key,value in self.Q[state].items():
if value > maxQstate:
maxQstate = value
maxQAction = key
elif value == maxQstate:
[maxQstate,maxQAction] = random.choice([[maxQstate,maxQAction],[value,key]])
if maxQstate == -10000000:
maxQstate = 0.0
"Find the policy (or best action) that corresponds to the best Q value"
self.P[state] = maxQAction
"Choose the value of the state to be the max Q value that the state has"
self.tempV[state] = self.Q[state][maxQAction]
"After all states have been updated, store tempV in V before the next iteration"
self.V = self.tempV.copy()
def __init__(self, mdp, discount = 0.9, iterations = 100):
"""
Your value iteration agent should take an mdp on
construction, run the indicated number of iterations
and then act according to the resulting policy.
Some useful mdp methods you will use:
mdp.getStates()
mdp.getPossibleActions(state)
mdp.getTransitionStatesAndProbs(state, action)
mdp.getReward(state, action, nextState)
mdp.isTerminal(state)
"""
self.mdp = mdp
self.discount = discount
self.iterations = iterations
self.values = util.Counter() # A Counter is a dict with default 0
# Write value iteration code here
"*** YOUR CODE HERE ***"
print "-----------------------------------------------------"
"*** MY CODE BEGINS ***"
k = 0
while k < iterations:
val = self.values.copy() #before each iteration, copy one.
for s in mdp.getStates():
if mdp.isTerminal(s) == False:
max = -999999
for action in mdp.getPossibleActions(s):
v = 0
for pos_pro in mdp.getTransitionStatesAndProbs(s,action):
v = v + pos_pro[1]*(mdp.getReward(s,action,pos_pro[0])+discount*self.values[pos_pro[0]])
if v > max:
max = v
val[s] = max
else:
for action in mdp.getPossibleActions(s):
v = 0
for pos_pro in mdp.getTransitionStatesAndProbs(s,action):
v = v + pos_pro[1]*(mdp.getReward(s,action,pos_pro[0])+discount*self.values[pos_pro[0]])
val[s] = v
k = k+1
for s in mdp.getStates():
self.values[s] = val[s]
def computeQValueFromValues(self, state, action):
"""
Compute the Q-value of action in state from the
value function stored in self.values.
"""
"*** YOUR CODE HERE ***"
mdp = self.mdp
gamma = self.discount
successors = mdp.getTransitionStatesAndProbs(state, action)
return sum([successor[1] * (mdp.getReward(state, action, successor[0]) + gamma * self.getValue(successor[0])) for successor in successors])