Source code for mindspore.nn.optim.adam

# Copyright 2020 Huawei Technologies Co., Ltd
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# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
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# http://www.apache.org/licenses/LICENSE-2.0
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# ============================================================================
"""adam"""
import numpy as np

from mindspore.common import dtype as mstype
from mindspore.common.initializer import initializer
from mindspore.ops import operations as P
from mindspore.ops import composite as C
from mindspore.ops import functional as F
from mindspore.common.parameter import Parameter
from mindspore.common.tensor import Tensor
from mindspore._checkparam import Validator as validator
from mindspore._checkparam import Rel
from .optimizer import Optimizer

_learning_rate_update_func = ['linear', 'cos', 'sin']

adam_opt = C.MultitypeFuncGraph("adam_opt")


@adam_opt.register("Tensor", "Tensor", "Tensor", "Tensor", "Tensor", "Tensor", "Tensor", "Tensor", "Tensor", "Bool")
def _update_run_op(beta1, beta2, eps, lr, weight_decay_tensor, param, m, v, gradient, decay_flag):
    """
    Update parameters.

    Args:
        beta1 (Tensor): The exponential decay rate for the 1st moment estimates. Should be in range (0.0, 1.0).
        beta2 (Tensor): The exponential decay rate for the 2nd moment estimates. Should be in range (0.0, 1.0).
        eps (Tensor): Term added to the denominator to improve numerical stability. Should be greater than 0.
        lr (Tensor): Learning rate.
        weight_decay_tensor (Tensor): Weight decay. Should be equal to or greater than 0.
        param (Tensor): Parameters.
        m (Tensor): m value of parameters.
        v (Tensor): v value of parameters.
        gradient (Tensor): Gradient of parameters.

    Returns:
        Tensor, the new value of v after updating.
    """
    op_mul = P.Mul()
    op_square = P.Square()
    op_sqrt = P.Sqrt()
    op_cast = P.Cast()
    op_reshape = P.Reshape()
    op_shape = P.Shape()

    param_fp32 = op_cast(param, mstype.float32)
    m_fp32 = op_cast(m, mstype.float32)
    v_fp32 = op_cast(v, mstype.float32)
    gradient_fp32 = op_cast(gradient, mstype.float32)

    next_m = op_mul(beta1, m_fp32) + op_mul(op_cast(F.tuple_to_array((1.0,)), mstype.float32) - beta1, gradient_fp32)

    next_v = op_mul(beta2, v_fp32) + op_mul(op_cast(F.tuple_to_array((1.0,)), mstype.float32)
                                            - beta2, op_square(gradient_fp32))

    update = next_m / (op_sqrt(next_v) + eps)
    if decay_flag:
        update = update + op_mul(weight_decay_tensor, param_fp32)

    update_with_lr = op_mul(lr, update)
    next_param = param_fp32 - op_reshape(update_with_lr, op_shape(param_fp32))

    next_v = F.depend(next_v, F.assign(param, next_param))
    next_v = F.depend(next_v, F.assign(m, next_m))
    next_v = F.depend(next_v, F.assign(v, next_v))
    return next_v


def _check_param_value(beta1, beta2, eps, weight_decay, prim_name):
    """Check the type of inputs."""
    validator.check_value_type("beta1", beta1, [float], prim_name)
    validator.check_value_type("beta2", beta2, [float], prim_name)
    validator.check_value_type("eps", eps, [float], prim_name)
    validator.check_value_type("weight_dacay", weight_decay, [float], prim_name)
    validator.check_number_range("beta1", beta1, 0.0, 1.0, Rel.INC_NEITHER, prim_name)
    validator.check_number_range("beta2", beta2, 0.0, 1.0, Rel.INC_NEITHER, prim_name)
    validator.check_number_range("eps", eps, 0.0, float("inf"), Rel.INC_NEITHER, prim_name)
    validator.check_number_range("weight_decay", weight_decay, 0.0, float("inf"), Rel.INC_LEFT, prim_name)


def _check_learning_rate_value(learning_rate, end_learning_rate, decay_steps, power, prim_name):
    """Check the type of inputs."""
    validator.check_float_positive('learning_rate', learning_rate, prim_name)
    validator.check_float_legal_value('learning_rate', learning_rate, prim_name)
    validator.check_float_positive('end_learning_rate', end_learning_rate, prim_name)
    validator.check_float_legal_value('end_learning_rate', end_learning_rate, prim_name)
    validator.check_float_positive('power', power, prim_name)
    validator.check_float_legal_value('power', power, prim_name)
    validator.check_integer('decay_steps', decay_steps, 0, Rel.GT, prim_name)


@adam_opt.register("Function", "Tensor", "Tensor", "Tensor", "Tensor", "Number", "Tensor", "Tensor", "Tensor", "Tensor",
                   "Tensor")
def _run_opt_with_one_number(opt, beta1_power, beta2_power, beta1, beta2, eps, lr, gradient, params, moment1,
                             moment2):
    """Apply adam optimizer to the weight parameter using Tensor."""
    success = True
    success = F.depend(success, opt(params, moment1, moment2, beta1_power, beta2_power, lr, beta1, beta2,
                                    eps, gradient))
    return success


[docs]class Adam(Optimizer): r""" Updates gradients by Adaptive Moment Estimation (Adam) algorithm. The Adam algorithm is proposed in `Adam: A Method for Stochastic Optimization <https://arxiv.org/abs/1412.6980>`_. The updating formulas are as follows, .. math:: \begin{array}{ll} \\ m = \beta_1 * m + (1 - \beta_1) * g \\ v = \beta_2 * v + (1 - \beta_2) * g * g \\ l = \alpha * \frac{\sqrt{1-\beta_2^t}}{1-\beta_1^t} \\ w = w - l * \frac{m}{\sqrt{v} + \epsilon} \end{array} :math:`m` represents the 1st moment vector `moment1`, :math:`v` represents the 2nd moment vector `moment2`, :math:`g` represents `gradients`, :math:`l` represents scaling factor `lr`, :math:`\beta_1, \beta_2` represent `beta1` and `beta2`, :math:`t` represents updating step while :math:`beta_1^t` and :math:`beta_2^t` represent `beta1_power` and `beta2_power`, :math:`\alpha` represents `learning_rate`, :math:`w` represents `params`, :math:`\epsilon` represents `eps`. Note: The Adam optimizer supports separating parameter groups. Different parameter groups can set different `learning_rate` and `weight_decay`. When separating parameter groups, the weight decay in each group will be applied on the parameters if the value of weight_decay > 0. When not separating parameter groups, the `weight_decay` in the API will be applied on the parameters if `weight_decay` > 0 and the 'beta' and 'gamma' are not in the name of parameters. Args: params (Union[list[Parameter], list[dict]]): When the `params` is a list of `Parameter` which will be updated, the element in `params` should be class `Parameter`. When the `params` is a list of `dict`, the "params", "lr" and "weight_decay" are the keys can be parsed. - params: Required. The value should be a list of `Parameter`. - lr: Optional. If "lr" in the keys, the value of corresponding learning rate will be used. If not, the `learning_rate` in the API will be used. - weight_decay: Optional. If "weight_decay" in the keys, the value of corresponding weight decay will be used. If not, the `weight_decay` in the API will be used. learning_rate (Union[float, Tensor, Iterable]): A value for the learning rate. When the learning_rate is Iterable or a Tensor and the dims of the Tensor is 1, use dynamic learning rate, then the i-th step will take the i-th value as the learning rate. When the learning_rate is float or learning_rate is a Tensor but the dims of the Tensor is 0, use fixed learning rate. Other cases are not supported. Default: 1e-3. beta1 (float): The exponential decay rate for the 1st moment estimates. Should be in range (0.0, 1.0). Default: 0.9. beta2 (float): The exponential decay rate for the 2nd moment estimates. Should be in range (0.0, 1.0). Default: 0.999. eps (float): Term added to the denominator to improve numerical stability. Should be greater than 0. Default: 1e-8. use_locking (bool): Whether to enable a lock to protect updating variable tensors. If True, updating of the var, m, and v tensors will be protected by a lock. If False, the result is unpredictable. Default: False. use_nesterov (bool): Whether to use Nesterov Accelerated Gradient (NAG) algorithm to update the gradients. If True, updates the gradients using NAG. If False, updates the gradients without using NAG. Default: False. weight_decay (float): Weight decay (L2 penalty). Default: 0.0. loss_scale (float): A floating point value for the loss scale. Should be equal to or greater than 1. Default: 1.0. Inputs: - **gradients** (tuple[Tensor]) - The gradients of `params`, the shape is the same as `params`. Outputs: Tensor[bool], the value is True. Examples: >>> net = Net() >>> #1) All parameters use the same learning rate and weight decay >>> optim = nn.Adam(params=net.trainable_params()) >>> >>> #2) Use parameter groups and set different values >>> conv_params = list(filter(lambda x: 'conv' in x.name, net.trainable_params())) >>> no_conv_params = list(filter(lambda x: 'conv' not in x.name, net.trainable_params())) >>> group_params = [{'params': conv_params, 'weight_decay': 0.01, 'lr': 0.01}, >>> {'params': no_conv_params}] >>> opt = nn.Adam(group_params, learning_rate=0.1, weight_decay=0.0) >>> # the conv_params's parameters will use a learning rate of 0.01 and a weight decay of 0.01 >>> # the no_cov_params's parameters don't set learning and weight decay. So they will use a >>> # learning rate of 0.1 and a weight decay of 0.0. >>> >>> loss = nn.SoftmaxCrossEntropyWithLogits() >>> model = Model(net, loss_fn=loss, optimizer=optim) """ def __init__(self, params, learning_rate=1e-3, beta1=0.9, beta2=0.999, eps=1e-8, use_locking=False, use_nesterov=False, weight_decay=0.0, loss_scale=1.0): super(Adam, self).__init__(learning_rate, params, weight_decay, loss_scale) _check_param_value(beta1, beta2, eps, weight_decay, self.cls_name) validator.check_value_type("use_locking", use_locking, [bool], self.cls_name) validator.check_value_type("use_nesterov", use_nesterov, [bool], self.cls_name) validator.check_value_type("loss_scale", loss_scale, [float], self.cls_name) validator.check_number_range("loss_scale", loss_scale, 1.0, float("inf"), Rel.INC_LEFT, self.cls_name) self.beta1 = Tensor(beta1, mstype.float32) self.beta2 = Tensor(beta2, mstype.float32) self.beta1_power = Parameter(initializer(1, [1], mstype.float32), name="beta1_power") self.beta2_power = Parameter(initializer(1, [1], mstype.float32), name="beta2_power") self.eps = eps self.moment1 = self.parameters.clone(prefix="moment1", init='zeros') self.moment2 = self.parameters.clone(prefix="moment2", init='zeros') self.hyper_map = C.HyperMap() self.opt = P.Adam(use_locking, use_nesterov) self.pow = P.Pow() self.sqrt = P.Sqrt() self.one = Tensor(np.array([1.0]).astype(np.float32)) self.realdiv = P.RealDiv() def construct(self, gradients): params = self.parameters moment1 = self.moment1 moment2 = self.moment2 gradients = self.decay_weight(gradients) gradients = self.scale_grad(gradients) lr = self.get_lr() beta1_power = self.beta1_power * self.beta1 self.beta1_power = beta1_power beta2_power = self.beta2_power * self.beta2 self.beta2_power = beta2_power if self.is_group_lr: success = self.hyper_map(F.partial(adam_opt, self.opt, beta1_power, beta2_power, self.beta1, self.beta2, self.eps), lr, gradients, params, moment1, moment2) else: success = self.hyper_map(F.partial(adam_opt, self.opt, beta1_power, beta2_power, self.beta1, self.beta2, self.eps, lr), gradients, params, moment1, moment2) return success
[docs]class AdamWeightDecay(Optimizer): """ Implements Adam algorithm weight decay fix. Args: params (list[Parameter]): A list of parameter, which will be updated. The element in `params` should be class mindspore.Parameter. learning_rate (Union[float, Tensor, Iterable]): A value for the learning rate. When the learning_rate is Iterable or a Tensor and the dims of the Tensor is 1, use dynamic learning rate, then the i-th step will take the i-th value as the learning rate. When the learning_rate is float or learning_rate is a Tensor but the dims of the Tensor is 0, use fixed learning rate. Other cases are not supported. Default: 1e-3. beta1 (float): The exponential decay rate for the 1st moment estimates. Default: 0.9. Should be in range (0.0, 1.0). beta2 (float): The exponential decay rate for the 2nd moment estimates. Default: 0.999. Should be in range (0.0, 1.0). eps (float): Term added to the denominator to improve numerical stability. Default: 1e-6. Should be greater than 0. weight_decay (float): Weight decay (L2 penalty). Default: 0.0. decay_filter (Function): A function to determine whether to apply weight decay on parameters. Default: lambda x: 'LayerNorm' not in x.name and 'bias' not in x.name. Inputs: - **gradients** (tuple[Tensor]) - The gradients of `params`, the shape is the same as `params`. Outputs: tuple[Parameter], the updated velocity value, the shape is the same as `params`. Examples: >>> net = Net() >>> loss = nn.SoftmaxCrossEntropyWithLogits() >>> optim = nn.AdamWeightDecay(params=net.trainable_params()) >>> model = Model(net, loss_fn=loss, optimizer=optim, metrics=None) """ def __init__(self, params, learning_rate=1e-3, beta1=0.9, beta2=0.999, eps=1e-6, weight_decay=0.0, decay_filter=lambda x: 'beta' not in x.name and 'gamma' not in x.name): super(AdamWeightDecay, self).__init__(learning_rate, params) if self.is_group: raise RuntimeError(f"The {self.cls_name} optimizer cannot support group setting.") _check_param_value(beta1, beta2, eps, weight_decay, self.cls_name) self.beta1 = Tensor(np.array([beta1]).astype(np.float32)) self.beta2 = Tensor(np.array([beta2]).astype(np.float32)) self.eps = Tensor(np.array([eps]).astype(np.float32)) self.weight_decay_tensor = Tensor(np.array([weight_decay]).astype(np.float32)) self.params = self.parameters self.moments1 = self.params.clone(prefix="adam_m", init='zeros') self.moments2 = self.params.clone(prefix="adam_v", init='zeros') self.decay_flag = tuple(decay_filter(x) for x in self.params) self.hyper_map = C.HyperMap() def construct(self, gradients): lr = self.get_lr() updated_velocity = self.hyper_map(F.partial(adam_opt, self.beta1, self.beta2, self.eps, lr, self.weight_decay_tensor), self.params, self.moments1, self.moments2, gradients, self.decay_flag) return updated_velocity
[docs]class AdamWeightDecayDynamicLR(Optimizer): """ Adam Weight Decay Dynamic Learning Rate (LR). Args: params (list[Parameter]): A list of parameter, which will be updated. The element in `params` should be class mindspore.Parameter. decay_steps (int): The steps of the decay. learning_rate (float): A floating point value for the learning rate. Default: 0.001. end_learning_rate (float): A floating point value for the end learning rate. Default: 0.0001. power (float): Power. Default: 10.0. beta1 (float): The exponential decay rate for the 1st moment estimates. Default: 0.9. Should be in range (0.0, 1.0). beta2 (float): The exponential decay rate for the 2nd moment estimates. Default: 0.999. Should be in range (0.0, 1.0). eps (float): Term added to the denominator to improve numerical stability. Default: 1e-6. Should be greater than 0. weight_decay (float): Weight decay (L2 penalty). Default: 0.0. decay_filter (Function): A function to determine whether to apply weight decay on parameters. Default: lambda x: 'LayerNorm' not in x.name and 'bias' not in x.name. Inputs: - **gradients** (tuple[Tensor]) - The gradients of `params`, the shape is the same as `params`. Outputs: tuple[Parameter], the updated velocity value, the shape is the same as `params`. Examples: >>> net = Net() >>> loss = nn.SoftmaxCrossEntropyWithLogits() >>> optim = nn.AdamWeightDecayDynamicLR(params=net.trainable_params(), decay_steps=10) >>> model = Model(net, loss_fn=loss, optimizer=optim, metrics=None) """ def __init__(self, params, decay_steps, learning_rate=0.001, end_learning_rate=0.0001, power=10.0, beta1=0.9, beta2=0.999, eps=1e-6, weight_decay=0.0, decay_filter=lambda x: 'beta' not in x.name and 'gamma' not in x.name, warmup_steps=0): super(AdamWeightDecayDynamicLR, self).__init__(learning_rate, params) if self.is_group: raise RuntimeError(f"The {self.cls_name} optimizer cannot support group setting.") _check_param_value(beta1, beta2, eps, weight_decay, self.cls_name) _check_learning_rate_value(learning_rate, end_learning_rate, decay_steps, power, self.cls_name) # turn them to scalar when me support scalar/tensor mix operations self.global_step = Parameter(initializer(0, [1]), name="global_step") self.warmup_steps = Tensor(np.array([warmup_steps]).astype(np.float32)) self.warmup_flag = False if warmup_steps > 0: self.warmup_flag = True self.decay_steps = Tensor(np.array([decay_steps]).astype(np.float32)) self.end_learning_rate = Tensor(np.array([end_learning_rate]).astype(np.float32)) self.diff_learning_rate = Tensor(np.array([learning_rate - end_learning_rate]).astype(np.float32)) self.power = power self.beta1 = Tensor(np.array([beta1]).astype(np.float32)) self.beta2 = Tensor(np.array([beta2]).astype(np.float32)) self.eps = Tensor(np.array([eps]).astype(np.float32)) self.weight_decay_tensor = Tensor(np.array([weight_decay]).astype(np.float32)) self.params = self.parameters self.moments1 = self.params.clone(prefix="adam_m", init='zeros') self.moments2 = self.params.clone(prefix="adam_v", init='zeros') self.decay_flag = tuple(decay_filter(x) for x in self.params) self.hyper_map = C.HyperMap() self.min = P.Minimum() self.pow = P.Pow() self.greater = P.Greater() self.one = Tensor(np.array([1.0]).astype(np.float32)) self.cast = P.Cast() self.start_learning_rate = Tensor(np.array([learning_rate]).astype(np.float32)) def construct(self, gradients): step = self.min(self.global_step, self.decay_steps) p = step / self.decay_steps lr = self.diff_learning_rate * self.pow(self.one - p, self.power) + self.end_learning_rate if self.warmup_flag: warmup_percent = self.global_step / self.warmup_steps warmup_lr = self.start_learning_rate * warmup_percent is_warmup = self.cast(self.greater(self.warmup_steps, self.global_step), mstype.float32) lr = (self.one - is_warmup) * lr + is_warmup * warmup_lr updated_velocity = self.hyper_map(F.partial(adam_opt, self.beta1, self.beta2, self.eps, lr, self.weight_decay_tensor), self.params, self.moments1, self.moments2, gradients, self.decay_flag) added_global_step = self.global_step + self.one F.control_depend(lr, added_global_step) self.global_step = added_global_step return updated_velocity