def test_MpiAdam():
np.random.seed(0)
tf.set_random_seed(0)
a = tf.Variable(np.random.randn(3).astype('float32'))
b = tf.Variable(np.random.randn(2, 5).astype('float32'))
loss = tf.reduce_sum(tf.square(a)) + tf.reduce_sum(tf.sin(b))
stepsize = 1e-2
update_op = tf.train.AdamOptimizer(stepsize).minimize(loss)
do_update = U.function([], loss, updates=[update_op])
tf.get_default_session().run(tf.global_variables_initializer())
for i in range(10):
print(i, do_update())
tf.set_random_seed(0)
tf.get_default_session().run(tf.global_variables_initializer())
var_list = [a, b]
lossandgrad = U.function([], [loss, U.flatgrad(loss, var_list)],
updates=[update_op])
adam = MpiAdam(var_list)
for i in range(10):
l, g = lossandgrad()
adam.update(g, stepsize)
print(i, l)
def learn(env, policy_fn, *,
timesteps_per_batch, # what to train on
max_kl, cg_iters,
gamma, lam, # advantage estimation
entcoeff=0.0,
cg_damping=1e-2,
vf_stepsize=3e-4,
vf_iters =3,
max_timesteps=0, max_episodes=0, max_iters=0, # time constraint
callback=None
):
nworkers = MPI.COMM_WORLD.Get_size()
rank = MPI.COMM_WORLD.Get_rank()
np.set_printoptions(precision=3)
# Setup losses and stuff
# ----------------------------------------
ob_space = env.observation_space
ac_space = env.action_space
pi = policy_fn("pi", ob_space, ac_space)
oldpi = policy_fn("oldpi", ob_space, ac_space)
atarg = tf.placeholder(dtype=tf.float32, shape=[None]) # Target advantage function (if applicable)
ret = tf.placeholder(dtype=tf.float32, shape=[None]) # Empirical return
ob = U.get_placeholder_cached(name="ob")
ac = pi.pdtype.sample_placeholder([None])
kloldnew = oldpi.pd.kl(pi.pd)
ent = pi.pd.entropy()
meankl = tf.reduce_mean(kloldnew)
meanent = tf.reduce_mean(ent)
entbonus = entcoeff * meanent
vferr = tf.reduce_mean(tf.square(pi.vpred - ret))
ratio = tf.exp(pi.pd.logp(ac) - oldpi.pd.logp(ac)) # advantage * pnew / pold
surrgain = tf.reduce_mean(ratio * atarg)
optimgain = surrgain + entbonus
losses = [optimgain, meankl, entbonus, surrgain, meanent]
loss_names = ["optimgain", "meankl", "entloss", "surrgain", "entropy"]
dist = meankl
all_var_list = pi.get_trainable_variables()
var_list = [v for v in all_var_list if v.name.split("/")[1].startswith("pol")]
var_list.extend([v for v in all_var_list if v.name.split("/")[1].startswith("me")])
vf_var_list = [v for v in all_var_list if v.name.split("/")[1].startswith("vf")]
vfadam = MpiAdam(vf_var_list)
get_flat = U.GetFlat(var_list)
set_from_flat = U.SetFromFlat(var_list)
klgrads = tf.gradients(dist, var_list)
flat_tangent = tf.placeholder(dtype=tf.float32, shape=[None], name="flat_tan")
shapes = [var.get_shape().as_list() for var in var_list]
start = 0
tangents = []
for shape in shapes:
sz = U.intprod(shape)
tangents.append(tf.reshape(flat_tangent[start:start+sz], shape))
start += sz
gvp = tf.add_n([tf.reduce_sum(g*tangent) for (g, tangent) in zipsame(klgrads, tangents)]) #pylint: disable=E1111
fvp = U.flatgrad(gvp, var_list)
assign_old_eq_new = U.function([],[], updates=[tf.assign(oldv, newv)
for (oldv, newv) in zipsame(oldpi.get_variables(), pi.get_variables())])
compute_losses = U.function([ob, ac, atarg], losses)
compute_lossandgrad = U.function([ob, ac, atarg], losses + [U.flatgrad(optimgain, var_list)])
compute_fvp = U.function([flat_tangent, ob, ac, atarg], fvp)
compute_vflossandgrad = U.function([ob, ret], U.flatgrad(vferr, vf_var_list))
@contextmanager
def timed(msg):
if rank == 0:
print(colorize(msg, color='magenta'))
tstart = time.time()
yield
print(colorize("done in %.3f seconds"%(time.time() - tstart), color='magenta'))
else:
yield
def allmean(x):
assert isinstance(x, np.ndarray)
out = np.empty_like(x)
MPI.COMM_WORLD.Allreduce(x, out, op=MPI.SUM)
out /= nworkers
return out
act_params = {
'name': "pi",
'ob_space': ob_space,
'ac_space': ac_space,
}
pi = ActWrapper(pi, act_params)
U.initialize()
th_init = get_flat()
MPI.COMM_WORLD.Bcast(th_init, root=0)
set_from_flat(th_init)
vfadam.sync()
print("Init param sum", th_init.sum(), flush=True)
# Prepare for rollouts
# ----------------------------------------
seg_gen = traj_segment_generator(pi, env, timesteps_per_batch, stochastic=True)
episodes_so_far = 0
timesteps_so_far = 0
iters_so_far = 0
tstart = time.time()
lenbuffer = deque(maxlen=40) # rolling buffer for episode lengths
rewbuffer = deque(maxlen=40) # rolling buffer for episode rewards
assert sum([max_iters>0, max_timesteps>0, max_episodes>0])==1
while True:
if callback: callback(locals(), globals())
if max_timesteps and timesteps_so_far >= max_timesteps:
break
elif max_episodes and episodes_so_far >= max_episodes:
break
elif max_iters and iters_so_far >= max_iters:
break
logger.log("********** Iteration %i ************"%iters_so_far)
with timed("sampling"):
seg = seg_gen.__next__()
add_vtarg_and_adv(seg, gamma, lam)
ob = np.concatenate([s['ob'] for s in seg], axis=0)
ac = np.concatenate([s['ac'] for s in seg], axis=0)
atarg = np.concatenate([s['adv'] for s in seg], axis=0)
tdlamret = np.concatenate([s['tdlamret'] for s in seg], axis=0)
vpredbefore = np.concatenate([s["vpred"] for s in seg], axis=0) # predicted value function before udpate
atarg = (atarg - atarg.mean()) / atarg.std() # standardized advantage function estimate
# if hasattr(pi, "ret_rms"): pi.ret_rms.update(tdlamret)
# if hasattr(pi, "ob_rms"): pi.ob_rms.update(ob) # update running mean/std for policy
args = ob, ac, atarg
fvpargs = [arr[::5] for arr in args]
def fisher_vector_product(p):
return allmean(compute_fvp(p, *fvpargs)) + cg_damping * p
assign_old_eq_new() # set old parameter values to new parameter values
with timed("computegrad"):
*lossbefore, g = compute_lossandgrad(*args)
lossbefore = allmean(np.array(lossbefore))
g = allmean(g)
if np.allclose(g, 0):
logger.log("Got zero gradient. not updating")
else:
with timed("cg"):
stepdir = cg(fisher_vector_product, g, cg_iters=cg_iters, verbose=rank==0)
assert np.isfinite(stepdir).all()
shs = .5*stepdir.dot(fisher_vector_product(stepdir))
lm = np.sqrt(shs / max_kl)
# logger.log("lagrange multiplier:", lm, "gnorm:", np.linalg.norm(g))
fullstep = stepdir / lm
expectedimprove = g.dot(fullstep)
surrbefore = lossbefore[0]
stepsize = 1.0
thbefore = get_flat()
for _ in range(10):
thnew = thbefore + fullstep * stepsize
set_from_flat(thnew)
meanlosses = surr, kl, *_ = allmean(np.array(compute_losses(*args)))
improve = surr - surrbefore
logger.log("Expected: %.3f Actual: %.3f"%(expectedimprove, improve))
if not np.isfinite(meanlosses).all():
logger.log("Got non-finite value of losses -- bad!")
elif kl > max_kl * 1.5:
logger.log("violated KL constraint. shrinking step.")
elif improve < 0:
logger.log("surrogate didn't improve. shrinking step.")
else:
logger.log("Stepsize OK!")
break
stepsize *= .5
else:
logger.log("couldn't compute a good step")
set_from_flat(thbefore)
if nworkers > 1 and iters_so_far % 20 == 0:
paramsums = MPI.COMM_WORLD.allgather((thnew.sum(), vfadam.getflat().sum())) # list of tuples
assert all(np.allclose(ps, paramsums[0]) for ps in paramsums[1:])
for (lossname, lossval) in zip(loss_names, meanlosses):
logger.record_tabular(lossname, lossval)
with timed("vf"):
for _ in range(vf_iters):
for (mbob, mbret) in dataset.iterbatches((ob, tdlamret),
include_final_partial_batch=False, batch_size=64):
g = allmean(compute_vflossandgrad(mbob, mbret))
vfadam.update(g, vf_stepsize)
logger.record_tabular("ev_tdlam_before", explained_variance(vpredbefore, tdlamret))
# lrlocal = (seg["ep_lens"], seg["ep_rets"]) # local values
lrlocal = (seg[0]["ep_lens"], seg[0]["ep_rets"]) # local values
listoflrpairs = MPI.COMM_WORLD.allgather(lrlocal) # list of tuples
lens, rews = map(flatten_lists, zip(*listoflrpairs))
lenbuffer.extend(lens)
rewbuffer.extend(rews)
logger.record_tabular("EpLenMean", np.mean(lenbuffer))
logger.record_tabular("EpRewMean", np.mean(rewbuffer))
logger.record_tabular("EpThisIter", len(lens))
episodes_so_far += len(lens)
timesteps_so_far += sum(lens)
iters_so_far += 1
logger.record_tabular("EpisodesSoFar", episodes_so_far)
logger.record_tabular("TimestepsSoFar", timesteps_so_far)
logger.record_tabular("TimeElapsed", time.time() - tstart)
if rank == 0:
logger.dump_tabular()
def __init__(
self,
env,
policy_fn,
*,
timesteps_per_batch, # what to train on
max_kl,
cg_iters,
gamma,
lam, # advantage estimation
entcoeff=0.0,
cg_damping=1e-2,
vf_stepsize=3e-4,
vf_iters=3,
max_timesteps=0,
max_episodes=0,
max_iters=0, # time constraint
callback=None,
max_path_length=None):
self.gamma = gamma
self.gae_lambda = lam
self.max_kl = max_kl
self.cg_iters = cg_iters
self.cg_damping = cg_damping
self.vf_stepsize = vf_stepsize
self.vf_iters = vf_iters
self.time_steps_per_batch = timesteps_per_batch
if max_path_length is None:
self.max_path_length = timesteps_per_batch
else:
self.max_path_length = max_path_length
self.nworkers = MPI.COMM_WORLD.Get_size()
self.rank = MPI.COMM_WORLD.Get_rank()
np.set_printoptions(precision=3)
# Setup losses and stuff
# ----------------------------------------
ob_space = env.observation_space
ac_space = env.action_space
pi = policy_fn("pi", ob_space, ac_space)
oldpi = policy_fn("oldpi", ob_space, ac_space)
atarg = tf.placeholder(
dtype=tf.float32,
shape=[None]) # Target advantage function (if applicable)
ret = tf.placeholder(dtype=tf.float32,
shape=[None]) # Empirical return
# n_size = tf.placeholder(dtype=tf.float32, shape=[None]) # neighborhood size
ob = U.get_placeholder_cached(name="ob")
ac = pi.pdtype.sample_placeholder([None])
kloldnew = oldpi.pd.kl(pi.pd)
ent = pi.pd.entropy()
meankl = tf.reduce_mean(kloldnew)
meanent = tf.reduce_mean(ent)
entbonus = entcoeff * meanent
vferr = tf.reduce_mean(tf.square(pi.vpred - ret))
# pred_n_error = tf.reduce_mean(tf.square(pi.predict_n - n_size))
ratio = tf.exp(pi.pd.logp(ac) -
oldpi.pd.logp(ac)) # advantage * pnew / pold
surrgain = tf.reduce_mean(ratio * atarg)
optimgain = surrgain + entbonus # - pred_n_error
losses = [optimgain, meankl, entbonus, surrgain, meanent,
vferr] # , pred_n_error]
self.loss_names = [
"optimgain", "meankl", "entloss", "surrgain", "entropy", "vf_loss"
] # , "pred_n_error"]
dist = meankl
all_var_list = pi.get_trainable_variables()
var_list = [
v for v in all_var_list if v.name.split("/")[1].startswith("pol")
]
var_list.extend(
[v for v in all_var_list if v.name.split("/")[1].startswith("me")])
vf_var_list = [
v for v in all_var_list if v.name.split("/")[1].startswith("vf")
]
# vf_var_list.extend([v for v in all_var_list if v.name.split("/")[1].startswith("me")])
self.vfadam = MpiAdam(vf_var_list)
self.get_flat = U.GetFlat(var_list)
self.set_from_flat = U.SetFromFlat(var_list)
klgrads = tf.gradients(dist, var_list)
flat_tangent = tf.placeholder(dtype=tf.float32,
shape=[None],
name="flat_tan")
shapes = [var.get_shape().as_list() for var in var_list]
start = 0
tangents = []
for shape in shapes:
sz = U.intprod(shape)
tangents.append(tf.reshape(flat_tangent[start:start + sz], shape))
start += sz
gvp = tf.add_n([
tf.reduce_sum(g * tangent)
for (g, tangent) in zipsame(klgrads, tangents)
]) # pylint: disable=E1111
fvp = U.flatgrad(gvp, var_list)
self.assign_old_eq_new = U.function(
[], [],
updates=[
tf.assign(oldv, newv) for (
oldv,
newv) in zipsame(oldpi.get_variables(), pi.get_variables())
])
self.compute_losses = U.function([ob, ac, atarg, ret], losses)
self.compute_lossandgrad = U.function(
[ob, ac, atarg, ret], losses + [U.flatgrad(optimgain, var_list)])
self.compute_fvp = U.function([flat_tangent, ob, ac, atarg], fvp)
self.compute_vflossandgrad = U.function([ob, ret],
U.flatgrad(vferr, vf_var_list))
act_params = {
'name': "pi",
'ob_space': ob_space,
'ac_space': ac_space,
}
self.pi = ActWrapper(pi, act_params)
U.initialize()
th_init = self.get_flat()
MPI.COMM_WORLD.Bcast(th_init, root=0)
self.set_from_flat(th_init)
self.vfadam.sync()
print("Init param sum", th_init.sum(), flush=True)
# self.seg_gen = traj_segment_generator(pi, env, timesteps_per_batch, stochastic=True)
if self.time_steps_per_batch > self.max_path_length:
self.nr_traj_seg_gens = int(self.time_steps_per_batch /
self.max_path_length)
self.seg_gen = [
copy_func(traj_segment_generator,
"traj_seg_gen_{}".format(i))(pi,
env,
timesteps_per_batch,
stochastic=True)
for i in range(self.nr_traj_seg_gens)
]
else:
self.nr_traj_seg_gens = 1
self.seg_gen = [
traj_segment_generator(pi,
env,
self.time_steps_per_batch,
stochastic=True)
]