File size: 6,028 Bytes
cc9dfd7
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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
from .torch_core import *
from torch.optim import Optimizer
import types

__all__ = ['StatScope', 'Statistic', 'ConstStatistic', 'AvgStatistic', 'AvgSquare', 'GeneralOptimizer']

StatScope = Enum('StatScope', 'Global Group Layer Channel Weight')

@dataclass
class Statistic():
    name:str
    param:float=0.9  # e.g. for exp moving average
    scope:StatScope=StatScope.Weight
    init:float=0.  # starting value

    @property
    def buf(self): return f'{self.name}_buffer'

    def new_step(self):
        "Set state when computing statistics for Global or Group"
        raise NotImplementedError

    def accumulate(self, val):
        "Add `val` to statistic"
        raise NotImplementedError

    def update(self, state, param, val=None, step=None):
        "Update state with accumlated, or `val` (if `Weight` or `Layer` scope)"
        raise NotImplementedError

class ConstStatistic(Statistic):
    @property
    def buf(self): return None
    def new_step(self):   pass
    def accumulate(self): pass
    def update(self, state, param, val=None, step=None): return param

@dataclass
class CounterStat(Statistic):
    def __post_init__(self): self.init,self._buf,self.name = 0,self.name,None
    @property
    def buf(self): return self._buf
    def new_step(self): pass
    def accumulate(self, val): pass
    def update(self, state, param, val=None, step=None): return state + 1

@dataclass
class AvgStatistic(Statistic):
    decay:bool=False
    debias:bool=False
    def new_step(self): self.val,self.count = 0.,0

    def accumulate(self, val):
        self.count += 1
        self.val += self._get_val1(val)

    def _get_val1(self, val): return val.mean()
    def _get_val2(self, state, val, param): return state.add_(1-param, val) if self.decay else state.add_(val)
    def _get_val3(self, state, val, param): 
        v = val.view(val.size(0), -1).mean(1)
        return state.add_(1-param, v) if self.decay else state.add_(v)

    def update(self, state, param, val=None, step=None):
        if self.scope == StatScope.Weight:
            # `state` is a tensor
            res = self._get_val2(state.mul_(param), val, param)
        elif self.scope == StatScope.Channel:
            # `state` is a tensor of size n_channels
            res = self._get_val3(state.mul_(param), val, param)
        # For everything else, `state` is a scalar
        elif self.scope == StatScope.Layer:  res = state*param + self._get_val1(val) * (1-param if self.decay else 1.)
        elif self.count != 0:                res = state*param + self.val/self.count * (1-param if self.decay else 1.)
        else: return state
        if self.debias and step is not None: res /= (1 - param ** step)
        return res

class AvgSquare(AvgStatistic):

    def __init__(self, name:str, param:float=0.9, scope=StatScope.Weight, init:float=0., decay:bool=True, debias:bool=False):
        super().__init__(name, param=param, scope=scope, init=init, decay=decay, debias=debias)

    def _get_val1(self, val): return torch.norm(val).pow(2)/val.numel()
    def _get_val2(self, state, val, param): 
        return state.addcmul_(1-param, val, val) if self.decay else state.addcmul_(val, val)
    def _get_val3(self, state, val, param):
        v = val.view(val.size(0), -1).mean(1)
        return state.addcmul_(1-param, v, v) if self.decay else state.addcmul_(v, v)

class GeneralOptimizer(Optimizer):
    def __init__(self, params, stats=None, on_step:Callable=None):
        defaults = {s.name:s.param for s in listify(stats) if s.name is not None}
        super().__init__(params, defaults)
        self.global_stats,self.group_stats,self.layer_stats,self.channel_stats,self.weight_stats = self._split_stats(stats)
        self.init_stats()
        if on_step is not None: self.on_step = types.MethodType(on_step, self)

    def step(self, closure=None):
        self.update_stats()
        for i,pg in enumerate(self.param_groups):
            for p in pg['params']:
                if p.grad is not None: self.on_step(p, pg, i)

    def on_step(self, p, group, group_idx): p.data.add_(-group['lr'], p.grad.data)

    def _split_stats(self, stats):
        splits = [[stat for stat in listify(stats) if stat.scope==scope] for scope in StatScope]
        for split,s in zip([splits[0], splits[1], splits[2]+splits[3]+splits[4]], StatScope):
            if np.any([getattr(s, 'debias', False) for s in split]): split.insert(0, CounterStat('step', scope=s))
        return splits

    def _init_stats(self, stats, data=None):
        return {stat.buf: stat.init if data is None
                else torch.zeros_like(data) + stat.init for stat in stats if stat.buf is not None}

    def init_stats(self):
        self.state['global'] = self._init_stats(self.global_stats)
        for i,pg in enumerate(self.param_groups):
            self.state[f'group{i}'] = self._init_stats(self.group_stats)
            for p in pg['params']:
                self.state[p] = self._init_stats(self.layer_stats)
                self.state[p].update(self._init_stats(self.channel_stats, p.data.view(p.data.size(0), -1).mean(1)))
                self.state[p].update(self._init_stats(self.weight_stats, p.data))

    def _set_bufs(self, p, stats, pg, val=None):
        d = self.state[p]
        for stat in stats:
            if stat.buf is not None: d[stat.buf] = stat.update(d[stat.buf], pg[stat.name], val=val, step=d.get('step', None))

    def update_stats(self):
        for stat in self.global_stats: stat.new_step()
        for i,pg in enumerate(self.param_groups):
            for stat in self.group_stats: stat.new_step()
            for p in pg['params']:
                if p.grad is not None:
                    for stat in self.global_stats + self.group_stats: stat.accumulate(p.grad.data)
                    self._set_bufs(p, self.layer_stats+self.channel_stats+self.weight_stats, pg, p.grad.data)
            self._set_bufs(f'group{i}', self.group_stats, pg)
        self._set_bufs('global', self.global_stats, self.param_groups[0])