-
Notifications
You must be signed in to change notification settings - Fork 0
/
mixmatch.py
173 lines (145 loc) · 7.16 KB
/
mixmatch.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
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""MixMatch training.
- Ensure class consistency by producing a group of `nu` augmentations of the same image and guessing the label for the
group.
- Sharpen the target distribution.
- Use the sharpened distribution directly as a smooth label in MixUp.
"""
import functools
import os
import numpy as np
import tensorflow as tf
from absl import app
from absl import flags
from libml import layers, utils, models
from libml.data import PAIR_DATASETS
from libml.layers import MixMode
from libml.utils import EasyDict
FLAGS = flags.FLAGS
class MixMatch(models.MultiModel):
def distribution_summary(self, p_data, p_model, p_target=None):
def kl(p, q):
p /= tf.reduce_sum(p)
q /= tf.reduce_sum(q)
return -tf.reduce_sum(p * tf.log(q / p))
tf.summary.scalar('metrics/kld', kl(p_data, p_model))
if p_target is not None:
tf.summary.scalar('metrics/kld_target', kl(p_data, p_target))
for i in range(self.nclass):
tf.summary.scalar('matching/class%d_ratio' % i, p_model[i] / p_data[i])
for i in range(self.nclass):
tf.summary.scalar('matching/val%d' % i, p_model[i])
def augment(self, x, l, beta, **kwargs):
assert 0, 'Do not call.'
def guess_label(self, y, classifier, T, **kwargs):
del kwargs
logits_y = [classifier(yi, training=True) for yi in y]
logits_y = tf.concat(logits_y, 0)
# Compute predicted probability distribution py.
p_model_y = tf.reshape(tf.nn.softmax(logits_y), [len(y), -1, self.nclass])
p_model_y = tf.reduce_mean(p_model_y, axis=0)
# Compute the target distribution.
p_target = tf.pow(p_model_y, 1. / T)
p_target /= tf.reduce_sum(p_target, axis=1, keep_dims=True)
return EasyDict(p_target=p_target, p_model=p_model_y)
def model(self, batch, lr, wd, ema, beta, w_match, warmup_kimg=1024, nu=2, mixmode='xxy.yxy', dbuf=128, **kwargs):
hwc = [self.dataset.height, self.dataset.width, self.dataset.colors]
xt_in = tf.placeholder(tf.float32, [batch] + hwc, 'xt') # For training
x_in = tf.placeholder(tf.float32, [None] + hwc, 'x')
y_in = tf.placeholder(tf.float32, [batch, nu] + hwc, 'y')
l_in = tf.placeholder(tf.int32, [batch], 'labels')
w_match *= tf.clip_by_value(tf.cast(self.step, tf.float32) / (warmup_kimg << 10), 0, 1)
lrate = tf.clip_by_value(tf.to_float(self.step) / (FLAGS.train_kimg << 10), 0, 1)
lr *= tf.cos(lrate * (7 * np.pi) / (2 * 8))
tf.summary.scalar('monitors/lr', lr)
augment = MixMode(mixmode)
classifier = lambda x, **kw: self.classifier(x, **kw, **kwargs).logits
# Moving average of the current estimated label distribution
p_model = layers.PMovingAverage('p_model', self.nclass, dbuf)
p_target = layers.PMovingAverage('p_target', self.nclass, dbuf) # Rectified distribution (only for plotting)
# Known (or inferred) true unlabeled distribution
p_data = layers.PData(self.dataset)
y = tf.reshape(tf.transpose(y_in, [1, 0, 2, 3, 4]), [-1] + hwc)
guess = self.guess_label(tf.split(y, nu), classifier, T=0.5, **kwargs)
ly = tf.stop_gradient(guess.p_target)
lx = tf.one_hot(l_in, self.nclass)
xy, labels_xy = augment([xt_in] + tf.split(y, nu), [lx] + [ly] * nu, [beta, beta])
x, y = xy[0], xy[1:]
labels_x, labels_y = labels_xy[0], tf.concat(labels_xy[1:], 0)
del xy, labels_xy
batches = layers.interleave([x] + y, batch)
skip_ops = tf.get_collection(tf.GraphKeys.UPDATE_OPS)
logits = [classifier(batches[0], training=True)]
post_ops = [v for v in tf.get_collection(tf.GraphKeys.UPDATE_OPS) if v not in skip_ops]
for batchi in batches[1:]:
logits.append(classifier(batchi, training=True))
logits = layers.interleave(logits, batch)
logits_x = logits[0]
logits_y = tf.concat(logits[1:], 0)
loss_xe = tf.nn.softmax_cross_entropy_with_logits_v2(labels=labels_x, logits=logits_x)
loss_xe = tf.reduce_mean(loss_xe)
loss_l2u = tf.square(labels_y - tf.nn.softmax(logits_y))
loss_l2u = tf.reduce_mean(loss_l2u)
tf.summary.scalar('losses/xe', loss_xe)
tf.summary.scalar('losses/l2u', loss_l2u)
self.distribution_summary(p_data(), p_model(), p_target())
# L2 regularization
loss_wd = sum(tf.nn.l2_loss(v) for v in utils.model_vars('classify') if 'kernel' in v.name)
tf.summary.scalar('losses/wd', loss_wd)
ema = tf.train.ExponentialMovingAverage(decay=ema)
ema_op = ema.apply(utils.model_vars())
ema_getter = functools.partial(utils.getter_ema, ema)
post_ops.append(ema_op)
train_op = tf.train.MomentumOptimizer(lr, 0.9, use_nesterov=True).minimize(
loss_xe + w_match * loss_l2u + wd * loss_wd, colocate_gradients_with_ops=True)
with tf.control_dependencies([train_op]):
train_op = tf.group(*post_ops)
return EasyDict(
xt=xt_in, x=x_in, y=y_in, label=l_in, train_op=train_op,
classify_raw=tf.nn.softmax(classifier(x_in, training=False)), # No EMA, for debugging.
classify_op=tf.nn.softmax(classifier(x_in, getter=ema_getter, training=False)))
def main(argv):
utils.setup_main()
del argv # Unused.
dataset = PAIR_DATASETS()[FLAGS.dataset]()
log_width = utils.ilog2(dataset.width)
model = MixMatch(
os.path.join(FLAGS.train_dir, dataset.name),
dataset,
lr=FLAGS.lr,
wd=FLAGS.wd,
arch=FLAGS.arch,
batch=FLAGS.batch,
nclass=dataset.nclass,
ema=FLAGS.ema,
beta=FLAGS.beta,
w_match=FLAGS.w_match,
scales=FLAGS.scales or (log_width - 2),
filters=FLAGS.filters,
repeat=FLAGS.repeat)
model.train(FLAGS.train_kimg << 10, FLAGS.report_kimg << 10)
if __name__ == '__main__':
utils.setup_tf()
flags.DEFINE_float('wd', 0.0005, 'Weight decay.')
flags.DEFINE_float('ema', 0.999, 'Exponential moving average of params.')
flags.DEFINE_float('beta', 0.5, 'Mixup beta distribution.')
flags.DEFINE_float('w_match', 100, 'Weight for distribution matching loss.')
flags.DEFINE_integer('scales', 0, 'Number of 2x2 downscalings in the classifier.')
flags.DEFINE_integer('filters', 32, 'Filter size of convolutions.')
flags.DEFINE_integer('repeat', 4, 'Number of residual layers per stage.')
FLAGS.set_default('augment', 'd.d.d')
FLAGS.set_default('dataset', 'cifar10.3@250-5000')
FLAGS.set_default('batch', 64)
FLAGS.set_default('lr', 0.03)
FLAGS.set_default('train_kimg', 1 << 16)
app.run(main)