-
Notifications
You must be signed in to change notification settings - Fork 29
/
_utils.py
265 lines (203 loc) · 8.78 KB
/
_utils.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
import torch
import higher
import random
import os
import csv
import typing
import numpy as np
def list_dir(root: str, prefix: bool = False) -> typing.List[str]:
"""List all directories at a given root
Args:
root (str): Path to directory whose folders need to be listed
prefix (bool, optional): If true, prepends the path to each result, otherwise
only returns the name of the directories found
"""
root = os.path.expanduser(root)
directories = [p for p in os.listdir(root) if os.path.isdir(os.path.join(root, p))]
if prefix is True:
directories = [os.path.join(root, d) for d in directories]
return directories
def list_files(root: str, suffix: str, prefix: bool = False) -> typing.List[str]:
"""List all files ending with a suffix at a given root
Args:
root (str): Path to directory whose folders need to be listed
suffix (str or tuple): Suffix of the files to match, e.g. '.png' or ('.jpg', '.png').
It uses the Python "str.endswith" method and is passed directly
prefix (bool, optional): If true, prepends the path to each result, otherwise
only returns the name of the files found
"""
root = os.path.expanduser(root)
files = [p for p in os.listdir(root) if os.path.isfile(os.path.join(root, p)) and p.endswith(suffix)]
if prefix is True:
files = [os.path.join(root, d) for d in files]
return files
def train_val_split(eps_data: typing.List[torch.Tensor], k_shot: int) -> typing.Dict[str, torch.Tensor]:
"""Split data into train and validation
Args:
eps_data: a list of 2 tensors:
+ first tensor: data
+ second tensor: labels
k_shot: number of training data per class
shuffle: shuffle data before splitting
Returns: a dictionary containing data splitted
"""
# get information of image size
nc, iH, iW = eps_data[0][0].shape
# get labels
labels, num_classes = normalize_labels(labels=eps_data[1])
v_shot = int(labels.numel() / num_classes) - k_shot
data = {
'x_t': torch.empty(size=(num_classes, k_shot, nc, iH, iW), device=eps_data[0].device),
'x_v': torch.empty(size=(num_classes, v_shot, nc, iH, iW), device=eps_data[0].device),
'y_t': torch.empty(size=(num_classes * k_shot,), dtype=torch.int64, device=eps_data[1].device),
'y_v': torch.empty(size=(num_classes * v_shot,), dtype=torch.int64, device=eps_data[1].device)
}
for cls_id in range(num_classes):
X = eps_data[0][labels == cls_id]
data['x_t'][cls_id, :, :, :, :] = X[:k_shot]
data['x_v'][cls_id, :, :, :, :] = X[k_shot:]
data['y_t'][k_shot * cls_id: k_shot * (cls_id + 1)] = torch.tensor(data=[cls_id] * k_shot, dtype=torch.int64, device=labels.device)
data['y_v'][v_shot * cls_id: v_shot * (cls_id + 1)] = torch.tensor(data=[cls_id] * v_shot, dtype=torch.int64, device=labels.device)
data['x_t'] = data['x_t'].view(num_classes * k_shot, nc, iH, iW)
data['x_v'] = data['x_v'].view(num_classes * v_shot, nc, iH, iW)
return data
def normalize_labels(labels: torch.Tensor) -> typing.Tuple[torch.Tensor, int]:
"""Normalize a list of labels, for example:
[11, 11, 20, 20, 60, 60, 6, 6] => [0, 0, 1, 1, 2, 2, 3, 3]
"""
if labels.ndim > 1:
raise ValueError("Input must be a 1d tensor, not {}".format(labels.ndim))
out = torch.empty_like(input=labels, device=labels.device)
label_dict = {}
for i in range(labels.numel()):
val = labels[i].item()
if val not in label_dict:
label_dict[val] = torch.tensor(data=len(label_dict), device=labels.device)
out[i] = label_dict[val]
return out, len(label_dict)
def train_val_split_regression(eps_data: typing.List[torch.Tensor], k_shot: float) -> typing.Dict[str, torch.Tensor]:
"""split the data for regression
Args:
eps_data: a list of 2 tensors: x and y
k_shot:
"""
data = {}
v_ids = [i for i in range(eps_data[0].numel())]
k_ids = random.sample(population=v_ids, k=k_shot)
v_ids = [v for v in v_ids if v not in k_ids]
# due to the usage of data loader, the data is in shape (1, num_samples)
# hence, we need to transpose to get the format of mini-batch of samples
eps_data_batch = [eps_data[i].T for i in range(len(eps_data))]
data['x_t'] = eps_data_batch[0][k_ids]
data['y_t'] = eps_data_batch[1][k_ids]
data['x_v'] = eps_data_batch[0][v_ids]
data['y_v'] = eps_data_batch[1][v_ids]
return data
def get_episodes(episode_file_path: typing.Optional[str] = None, num_episodes: int = 100) -> typing.List[str]:
"""Get episodes from a file
Args:
episode_file_path:
num_episodes: dummy variable in training to create an infinite
episode (str) generator. In testing, it defines how many
episodes to evaluate
Return: an episode (str) generator
"""
# get episode list if not None
if episode_file_path is not None:
episodes = []
with open(file=episode_file_path, mode='r') as f_csv:
csv_rd = csv.reader(f_csv, delimiter=',')
episodes = list(csv_rd)
else:
episodes = [None] * num_episodes
return episodes
def _weights_init(m):
classname = m.__class__.__name__
if classname.find('Conv') != -1:
if m.weight is not None:
torch.nn.init.kaiming_normal_(m.weight.data)
if m.bias is not None:
torch.nn.init.zeros_(m.bias.data)
elif classname.find('BatchNorm') != -1:
if m.weight is not None:
torch.nn.init.normal_(m.weight.data, 1.0, 0.02)
torch.nn.init.constant_(m.bias.data, 0)
def euclidean_distance(matrixN: torch.Tensor, matrixM: torch.Tensor) -> torch.Tensor:
"""Calculate Euclidean distance from N points to M points
Args:
matrixN: an N x D matrix for N points
matrixM: a M x D matrix for M points
Returns: N x M matrix
"""
N = matrixN.size(0)
M = matrixM.size(0)
D = matrixN.size(1)
assert D == matrixM.size(1)
matrixN = matrixN.unsqueeze(1).expand(N, M, D)
matrixM = matrixM.unsqueeze(0).expand(N, M, D)
return torch.norm(input=matrixN - matrixM, p='fro', dim=2)
def get_cls_prototypes(x: torch.Tensor, y: torch.Tensor) -> torch.Tensor:
"""Calculate the prototypes/centroids
Args:
x: input data
y: corresponding labels
Returns: a tensor of prototypes with shape (C, d),
where C is the number of classes, d is the embedding dimension
"""
_, d = x.shape
cls_idx = torch.unique(input=y, return_counts=False)
C = cls_idx.shape[0]
prototypes = torch.empty(size=(C, d), device=x.device)
for c in range(C):
prototypes[c, :] = torch.mean(input=x[y == cls_idx[c]], dim=0)
return prototypes
def kl_divergence_gaussians(p: typing.List[torch.Tensor], q: typing.List[torch.Tensor]) -> torch.Tensor:
"""Calculate KL divergence between 2 diagonal Gaussian
Args: each paramter is list with 1st half as mean, and the 2nd half is log_std
Returns: KL divergence
"""
assert len(p) == len(q)
n = len(p) // 2
kl_div = 0
for i in range(n):
p_mean = p[i]
p_log_std = p[n + i]
q_mean = q[i]
q_log_std = q[n + i]
s1_vec = torch.exp(input=2 * q_log_std)
mahalanobis = torch.sum(input=torch.square(input=p_mean - q_mean) / s1_vec)
tr_s1inv_s0 = torch.sum(input=torch.exp(input=2 * (p_log_std - q_log_std)))
log_det = 2 * torch.sum(input=q_log_std - p_log_std)
kl_div_temp = mahalanobis + tr_s1inv_s0 + log_det - torch.numel(p_mean)
kl_div_temp = kl_div_temp / 2
kl_div = kl_div + kl_div_temp
return kl_div
def vector_to_list_parameters(vec: torch.Tensor, parameter_shapes: typing.List) -> torch.Tensor:
"""
"""
params = []
# Pointer for slicing the vector for each parameter
pointer = 0
for param_shape in parameter_shapes:
# The length of the parameter
num_param = np.prod(a=param_shape)
params.append(vec[pointer:pointer + num_param].view(param_shape))
# Increment the pointer
pointer += num_param
return params
def intialize_parameters(state_dict: dict) -> typing.List[torch.Tensor]:
""""""
p = list(state_dict.values())
for m in p:
if m.ndim > 1:
torch.nn.init.kaiming_normal_(tensor=m, nonlinearity='relu')
else:
torch.nn.init.zeros_(tensor=m)
return p
def torch_module_to_functional(torch_net: torch.nn.Module) -> higher.patch._MonkeyPatchBase:
"""Convert a conventional torch module to its "functional" form
"""
f_net = higher.patch.make_functional(module=torch_net)
f_net.track_higher_grads = False
f_net._fast_params = [[]]
return f_net