remove YellowFin because it's not worth maintaining

This commit is contained in:
Connor Olding 2019-02-03 15:03:03 +01:00
parent 5fd2b7b546
commit 0d28882ef0

View file

@ -248,141 +248,6 @@ class MomentumClip(Optimizer):
return -self.lr * self.accum
class YellowFin(Optimizer):
# paper: https://arxiv.org/abs/1706.03471
# knowyourmeme: http://cs.stanford.edu/~zjian/project/YellowFin/
# author's implementation:
# https://github.com/JianGoForIt/YellowFin/blob/master/tuner_utils/yellowfin.py
# code lifted:
# https://gist.github.com/botev/f8b32c00eafee222e47393f7f0747666
def __init__(self, lr=0.1, mu=0.0, beta=0.999, window_size=20,
debias=True, clip=1.0):
self.lr_default = _f(lr)
self.mu_default = _f(mu)
self.beta = _f(beta)
self.window_size = int(window_size) # curv_win_width
self.debias_enabled = bool(debias)
self.clip = _f(clip)
self.mu = _f(mu) # momentum
super().__init__(lr)
def reset(self):
self.accum = None
self.lr = self.lr_default
self.mu = self.mu_default
self.step = 0
self.beta_t = self.beta
self.curv_win = np.zeros([self.window_size, ], dtype=np.float32)
self.h_min = None
self.h_max = None
self.g_lpf = 0
# self.g_squared_lpf = 0
self.g_norm_squared_lpf = 0
self.g_norm_lpf = 0
self.h_min_lpf = 0
self.h_max_lpf = 0
self.dist_lpf = 0
self.lr_lpf = 0
self.mu_lpf = 0
def get_lr_mu(self):
p = (np.square(self.dist_avg) * np.square(self.h_min)) \
/ (2 * self.g_var)
w3 = p * (np.sqrt(0.25 + p / 27.0) - 0.5)
w = np.power(w3, 1/3)
y = w - p / (3 * w)
sqrt_mu1 = y + 1
sqrt_h_min = np.sqrt(self.h_min)
sqrt_h_max = np.sqrt(self.h_max)
sqrt_mu2 = (sqrt_h_max - sqrt_h_min) / (sqrt_h_max + sqrt_h_min)
sqrt_mu = max(sqrt_mu1, sqrt_mu2)
if sqrt_mu2 > sqrt_mu1:
print('note: taking dr calculation. something may have exploded.')
lr = np.square(1 - sqrt_mu) / self.h_min
mu = np.square(sqrt_mu)
return lr, mu
def compute(self, dW, W):
if self.accum is None:
self.accum = np.zeros_like(dW)
# TODO: prevent allocations everywhere by using [:].
# assuming that really works. i haven't actually checked.
total_norm = np.linalg.norm(dW)
clip_scale = self.clip / (total_norm + 1e-6)
if clip_scale < 1:
# print("clipping gradients; norm: {:10.5f}".format(total_norm))
dW *= clip_scale
# fmt = 'W std: {:10.7f}e-3, dWstd: {:10.7f}e-3, V std: {:10.7f}e-3'
# print(fmt.format(np.std(W), np.std(dW) * 100, np.std(V) * 100))
b = self.beta
m1b = 1 - self.beta
debias = 1 / (1 - self.beta_t) if self.debias_enabled else 1
g = dW
g_squared = np.square(g)
g_norm_squared = np.sum(g_squared)
g_norm = np.sqrt(g_norm_squared)
self.curv_win[self.step % self.window_size] = g_norm_squared
valid_window = self.curv_win[:min(self.window_size, self.step + 1)]
h_min_t = np.min(valid_window)
h_max_t = np.max(valid_window)
self.g_lpf = b * self.g_lpf + m1b * g
# self.g_squared_lpf = b * self.g_squared_lpf + m1b * g_squared
self.g_norm_squared_lpf = b * self.g_norm_squared_lpf \
+ m1b * g_norm_squared
self.g_norm_lpf = b * self.g_norm_lpf + m1b * g_norm
self.h_min_lpf = b * self.h_min_lpf + m1b * h_min_t
self.h_max_lpf = b * self.h_max_lpf + m1b * h_max_t
g_avg = debias * self.g_lpf
# g_squared_avg = debias * self.g_squared_lpf
g_norm_squared_avg = debias * self.g_norm_squared_lpf
g_norm_avg = debias * self.g_norm_lpf
self.h_min = debias * self.h_min_lpf
self.h_max = debias * self.h_max_lpf
assert self.h_max >= self.h_min
dist = g_norm_avg / g_norm_squared_avg
self.dist_lpf = b * self.dist_lpf + m1b * dist
self.dist_avg = debias * self.dist_lpf
self.g_var = g_norm_squared_avg - np.sum(np.square(g_avg))
# equivalently:
# self.g_var = np.sum(np.abs(g_squared_avg - np.square(g_avg)))
if self.step > 0:
lr_for_real, mu_for_real = self.get_lr_mu()
self.mu_lpf = b * self.mu_lpf + m1b * mu_for_real
self.lr_lpf = b * self.lr_lpf + m1b * lr_for_real
self.mu = debias * self.mu_lpf
self.lr = debias * self.lr_lpf
self.accum[:] = self.accum * self.mu - self.lr * dW
V = self.accum
self.step += 1
self.beta_t *= self.beta
return V
class AddSign(Optimizer):
# paper: https://arxiv.org/abs/1709.07417