bayesiancnn/uncertainty_estimation.py

185 lines
6.9 KiB
Python
Executable File

import argparse
import torch
import numpy as np
import pandas as pd
import seaborn as sns
from PIL import Image
import torchvision
from torch.nn import functional as F
import torchvision.transforms as transforms
import matplotlib.pyplot as plt
import data
from main_bayesian import getModel
import config_bayesian as cfg
# CUDA settings
device = torch.device("cuda:0" if torch.cuda.is_available() else "cpu")
mnist_set = None
notmnist_set = None
transform = transforms.Compose([
transforms.ToPILImage(),
transforms.Resize((32, 32)),
transforms.ToTensor(),
])
def init_dataset(notmnist_dir):
global mnist_set
global notmnist_set
mnist_set, _, _, _ = data.getDataset('MNIST')
notmnist_set = torchvision.datasets.ImageFolder(root=notmnist_dir)
def get_uncertainty_per_image(model, input_image, T=15, normalized=False):
input_image = input_image.unsqueeze(0)
input_images = input_image.repeat(T, 1, 1, 1)
net_out, _ = model(input_images)
pred = torch.mean(net_out, dim=0).cpu().detach().numpy()
if normalized:
prediction = F.softplus(net_out)
p_hat = prediction / torch.sum(prediction, dim=1).unsqueeze(1)
else:
p_hat = F.softmax(net_out, dim=1)
p_hat = p_hat.detach().cpu().numpy()
p_bar = np.mean(p_hat, axis=0)
temp = p_hat - np.expand_dims(p_bar, 0)
epistemic = np.dot(temp.T, temp) / T
epistemic = np.diag(epistemic)
aleatoric = np.diag(p_bar) - (np.dot(p_hat.T, p_hat) / T)
aleatoric = np.diag(aleatoric)
return pred, epistemic, aleatoric
def get_uncertainty_per_batch(model, batch, T=15, normalized=False):
batch_predictions = []
net_outs = []
batches = batch.unsqueeze(0).repeat(T, 1, 1, 1, 1)
preds = []
epistemics = []
aleatorics = []
for i in range(T): # for T batches
net_out, _ = model(batches[i].cuda())
net_outs.append(net_out)
if normalized:
prediction = F.softplus(net_out)
prediction = prediction / torch.sum(prediction, dim=1).unsqueeze(1)
else:
prediction = F.softmax(net_out, dim=1)
batch_predictions.append(prediction)
for sample in range(batch.shape[0]):
# for each sample in a batch
pred = torch.cat([a_batch[sample].unsqueeze(0) for a_batch in net_outs], dim=0)
pred = torch.mean(pred, dim=0)
preds.append(pred)
p_hat = torch.cat([a_batch[sample].unsqueeze(0) for a_batch in batch_predictions], dim=0).detach().cpu().numpy()
p_bar = np.mean(p_hat, axis=0)
temp = p_hat - np.expand_dims(p_bar, 0)
epistemic = np.dot(temp.T, temp) / T
epistemic = np.diag(epistemic)
epistemics.append(epistemic)
aleatoric = np.diag(p_bar) - (np.dot(p_hat.T, p_hat) / T)
aleatoric = np.diag(aleatoric)
aleatorics.append(aleatoric)
epistemic = np.vstack(epistemics) # (batch_size, categories)
aleatoric = np.vstack(aleatorics) # (batch_size, categories)
preds = torch.cat([i.unsqueeze(0) for i in preds]).cpu().detach().numpy() # (batch_size, categories)
return preds, epistemic, aleatoric
def get_sample(dataset, sample_type='mnist'):
idx = np.random.randint(len(dataset.targets))
if sample_type=='mnist':
sample = dataset.data[idx]
truth = dataset.targets[idx]
else:
path, truth = dataset.samples[idx]
sample = torch.from_numpy(np.array(Image.open(path)))
sample = sample.unsqueeze(0)
sample = transform(sample)
return sample.to(device), truth
def run(net_type, weight_path, notmnist_dir):
init_dataset(notmnist_dir)
layer_type = cfg.layer_type
activation_type = cfg.activation_type
net = getModel(net_type, 1, 10, priors=None, layer_type=layer_type, activation_type=activation_type)
net.load_state_dict(torch.load(weight_path))
net.train()
net.to(device)
fig = plt.figure()
fig.suptitle('Uncertainty Estimation', fontsize='x-large')
mnist_img = fig.add_subplot(321)
notmnist_img = fig.add_subplot(322)
epi_stats_norm = fig.add_subplot(323)
ale_stats_norm = fig.add_subplot(324)
epi_stats_soft = fig.add_subplot(325)
ale_stats_soft = fig.add_subplot(326)
sample_mnist, truth_mnist = get_sample(mnist_set)
pred_mnist, epi_mnist_norm, ale_mnist_norm = get_uncertainty_per_image(net, sample_mnist, T=25, normalized=True)
pred_mnist, epi_mnist_soft, ale_mnist_soft = get_uncertainty_per_image(net, sample_mnist, T=25, normalized=False)
mnist_img.imshow(sample_mnist.squeeze().cpu(), cmap='gray')
mnist_img.axis('off')
mnist_img.set_title('MNIST Truth: {} Prediction: {}'.format(int(truth_mnist), int(np.argmax(pred_mnist))))
sample_notmnist, truth_notmnist = get_sample(notmnist_set, sample_type='notmnist')
pred_notmnist, epi_notmnist_norm, ale_notmnist_norm = get_uncertainty_per_image(net, sample_notmnist, T=25, normalized=True)
pred_notmnist, epi_notmnist_soft, ale_notmnist_soft = get_uncertainty_per_image(net, sample_notmnist, T=25, normalized=False)
notmnist_img.imshow(sample_notmnist.squeeze().cpu(), cmap='gray')
notmnist_img.axis('off')
notmnist_img.set_title('notMNIST Truth: {}({}) Prediction: {}({})'.format(
int(truth_notmnist), chr(65 + truth_notmnist), int(np.argmax(pred_notmnist)), chr(65 + np.argmax(pred_notmnist))))
x = list(range(10))
data = pd.DataFrame({
'epistemic_norm': np.hstack([epi_mnist_norm, epi_notmnist_norm]),
'aleatoric_norm': np.hstack([ale_mnist_norm, ale_notmnist_norm]),
'epistemic_soft': np.hstack([epi_mnist_soft, epi_notmnist_soft]),
'aleatoric_soft': np.hstack([ale_mnist_soft, ale_notmnist_soft]),
'category': np.hstack([x, x]),
'dataset': np.hstack([['MNIST']*10, ['notMNIST']*10])
})
print(data)
sns.barplot(x='category', y='epistemic_norm', hue='dataset', data=data, ax=epi_stats_norm)
sns.barplot(x='category', y='aleatoric_norm', hue='dataset', data=data, ax=ale_stats_norm)
epi_stats_norm.set_title('Epistemic Uncertainty (Normalized)')
ale_stats_norm.set_title('Aleatoric Uncertainty (Normalized)')
sns.barplot(x='category', y='epistemic_soft', hue='dataset', data=data, ax=epi_stats_soft)
sns.barplot(x='category', y='aleatoric_soft', hue='dataset', data=data, ax=ale_stats_soft)
epi_stats_soft.set_title('Epistemic Uncertainty (Softmax)')
ale_stats_soft.set_title('Aleatoric Uncertainty (Softmax)')
plt.show()
if __name__ == '__main__':
parser = argparse.ArgumentParser(description = "PyTorch Uncertainty Estimation b/w MNIST and notMNIST")
parser.add_argument('--net_type', default='lenet', type=str, help='model')
parser.add_argument('--weights_path', default='checkpoints/MNIST/bayesian/model_lenet.pt', type=str, help='weights for model')
parser.add_argument('--notmnist_dir', default='data/notMNIST_small/', type=str, help='weights for model')
args = parser.parse_args()
run(args.net_type, args.weights_path, args.notmnist_dir)