BOTorch working

This commit is contained in:
Niko Feith 2023-04-21 12:27:29 +02:00
parent 0cf7850cda
commit 72f3e4e361
2 changed files with 48 additions and 29 deletions

View File

@ -1,6 +1,7 @@
import numpy as np
from scipy.stats import norm
def ExpectedImprovement(gp, X, nr_test, nr_weights, kappa=2.576, seed=None, lower=-1.0, upper=1.0):
y_hat = gp.predict(X)
best_y = max(y_hat)

View File

@ -8,21 +8,27 @@ from gpytorch.mlls import ExactMarginalLogLikelihood
from botorch.acquisition import UpperConfidenceBound, ExpectedImprovement, ProbabilityOfImprovement
import warnings
from botorch.exceptions.warnings import InputDataWarning, BadInitialCandidatesWarning
from PolicyModel.GaussianModel import GaussianPolicy
from ToyTask.MountainCarGym import Continuous_MountainCarEnv
import matplotlib.pyplot as plt
torch.set_default_dtype(torch.float64)
warnings.filterwarnings("ignore", category=InputDataWarning)
warnings.filterwarnings("ignore", category=BadInitialCandidatesWarning)
class BayesianOptimization:
def __init__(self, env, nr_steps, nr_init=3, acq="Expected Improvement", nr_weights=6, policy_seed=None):
def __init__(self, env, nr_steps, nr_init=5, acq="Expected Improvement", nr_weights=6, policy_seed=None):
self.env = env
self.nr_init = nr_init
self.acq = acq
self.X = None
self.Y = None
self.X_np = None
self.Y_np = None
self.GP = None
self.episode = 0
@ -34,7 +40,7 @@ class BayesianOptimization:
self.nr_steps = nr_steps
self.policy_seed = policy_seed
self.lower_bound = -1.0
self.lower_bound = 0
self.upper_bound = 1.0
self.bounds = torch.t(torch.tensor([[self.lower_bound, self.upper_bound]]*self.nr_policy_weights))
@ -45,7 +51,8 @@ class BayesianOptimization:
self.lower_bound,
self.upper_bound)
self.eval_X = 512
self.eval_X = 200
self.eval_restarts = 5
def reset_bo(self):
self.counter_array = np.empty((1, 1))
@ -82,82 +89,90 @@ class BayesianOptimization:
self.reset_bo()
self.X = torch.zeros((self.nr_init, self.nr_policy_weights))
self.Y = torch.zeros((self.nr_init, 1))
self.X_np = np.zeros((self.nr_init, self.nr_policy_weights))
self.Y_np = np.zeros((self.nr_init, 1))
for i in range(self.nr_init):
self.policy_model.random_policy()
self.X[i, :] = torch.tensor(self.policy_model.weights.T)
self.X_np[i, :] = self.policy_model.weights.T.clip(min=-1.0, max=1.0)
self.X[i, :] = torch.tensor((self.policy_model.weights.T.clip(min=-1.0, max=1.0) + 1)/2)
policy = self.policy_model.policy_rollout()
reward, step_count = self.runner(policy)
self.Y[i] = reward
self.Y_np[i] = reward
self.GP = SingleTaskGP(train_X=self.X, train_Y=self.Y, covar_module=MaternKernel(nu=1.5))
Y = torch.tensor(self.Y_np)
self.GP = SingleTaskGP(train_X=self.X, train_Y=Y, covar_module=MaternKernel(nu=1.5))
mll = ExactMarginalLogLikelihood(self.GP.likelihood, self.GP)
fit_gpytorch_mll(mll)
def next_observation(self):
if self.acq == "Expected Improvement":
ei = ExpectedImprovement(self.GP, best_f=self.Y.max())
ei = ExpectedImprovement(self.GP, best_f=self.best_reward[-1][0], maximize=True)
x_next, _ = optimize_acqf(ei,
bounds=self.bounds,
num_restarts=5,
num_restarts=self.eval_restarts,
raw_samples=self.eval_X,
q=1)
elif self.acq == "Probability of Improvement":
poi = ProbabilityOfImprovement(self.GP, best_f=self.Y.max())
poi = ProbabilityOfImprovement(self.GP, best_f=self.best_reward[-1][0], maximize=True)
x_next, _ = optimize_acqf(poi,
bounds=self.bounds,
num_restarts=5,
num_restarts=self.eval_restarts,
raw_samples=self.eval_X,
q=1)
elif self.acq == "Upper Confidence Bound":
ucb = UpperConfidenceBound(self.GP, beta=2.576)
ucb = UpperConfidenceBound(self.GP, beta=2.576, maximize=True)
x_next, _ = optimize_acqf(ucb,
bounds=self.bounds,
num_restarts=5,
num_restarts=self.eval_restarts,
raw_samples=self.eval_X,
q=1)
else:
raise NotImplementedError
return x_next
return torch.t(x_next)
def eval_new_observation(self, x_next):
self.policy_model.weights = x_next.detach().numpy()
new_weight = x_next.detach().numpy() * 2 - 1
self.policy_model.weights = new_weight
policy = self.policy_model.policy_rollout()
reward, step_count = self.runner(policy)
self.X = torch.vstack((self.X, x_next.reshape(1, -1)))
self.Y = torch.vstack((self.Y, torch.tensor(reward).reshape(1, -1)))
x_clipped = x_next.clip(min=-1.0, max=1.0)
self.GP = SingleTaskGP(train_X=self.X, train_Y=self.Y, covar_module=MaternKernel(nu=1.5))
self.X_np = np.vstack((self.X_np, new_weight.reshape(1, -1)))
self.X = torch.vstack((self.X, x_next.reshape(1, -1)))
self.Y_np = np.vstack((self.Y_np, reward))
Y = torch.tensor(self.Y_np)
self.GP = SingleTaskGP(train_X=self.X, train_Y=Y, covar_module=MaternKernel(nu=1.5))
mll = ExactMarginalLogLikelihood(self.GP.likelihood, self.GP)
fit_gpytorch_mll(mll)
if self.episode == 0:
self.best_reward[0] = torch.max(self.Y, 1).detach().numpy()
self.best_reward[0] = max(self.Y_np)
else:
self.best_reward = np.vstack((self.best_reward, torch.max(self.Y, 1).detach().numpy()))
self.best_reward = np.vstack((self.best_reward, max(self.Y_np)))
self.episode += 1
return step_count
def add_new_observation(self, reward, x_new):
self.X = torch.vstack((self.X, torch.tensor(x_new)))
self.Y = torch.vstack((self.Y, torch.tensor(reward)))
self.Y_np = np.vstack((self.Y_np, reward))
if self.episode == 0:
self.best_reward[0] = torch.max(self.Y, 1).detach().numpy()
self.best_reward[0] = max(self.Y_np)
else:
self.best_reward = np.vstack((self.best_reward, torch.max(self.Y, 1).detach().numpy()))
self.best_reward = np.vstack((self.best_reward, max(self.Y_np)))
self.episode += 1
@ -175,7 +190,7 @@ class BayesianOptimization:
def main():
nr_steps = 100
env = Continuous_MountainCarEnv() # render_mode='human'
bo = BayesianOptimization(env, nr_steps, acq="Expected Improvement")
bo = BayesianOptimization(env, nr_steps, nr_weights=5, acq="Expected Improvement")
bo.initialize()
iteration_steps = 200
for i in range(iteration_steps):
@ -184,6 +199,9 @@ def main():
print(bo.episode, bo.best_reward[-1][0], step_count)
print(bo.Y_np)
print(bo.X_np)
if __name__ == "__main__":
main()