Differences with torch.optim.RMSProp

torch.optim.RMSProp

class torch.optim.RMSProp(
    params,
    lr=0.01,
    alpha=0.99,
    eps=1e-08,
    weight_decay=0,
    momentum=0,
    centered=False
)

For more information, see torch.optim.RMSProp.

mindspore.nn.RMSProp

class mindspore.nn.RMSProp(
    params,
    learning_rate=0.1,
    decay=0.9,
    momentum=0.0,
    epsilon=1e-10,
    use_locking=False,
    centered=False,
    loss_scale=1.0,
    weight_decay=0.0
)

For more information, see mindspore.nn.RMSProp.

Differences

PyTorch and MindSpore implement different algorithms for this optimizer. Please refer to the formula on the official website for details.

Categories	Subcategories	PyTorch	MindSpore	Difference
Parameters	Parameter 1	params	params	Consistent function
	Parameter 2	lr	learning_rate	Consistent function, different parameter names and default values
	Parameter 3	alpha	decay	Consistent function, different parameter names and default values
	Parameter 4	eps	epsilon	Consistent function, different parameter names and default values
	Parameter 5	weight_decay	weight_decay	Consistent function
	Parameter 6	momentum	momentum	Consistent function
	Parameter 7	centered	centered	Consistent function
	Parameter 8	-	use_locking	MindSpore use_locking controls whether to update the network weights, and PyTorch does not have this parameter
	Parameter 9	-	loss_scale	MindSpore loss_scale is the gradient scaling factor, and PyTorch does not have this parameter

Code Example

# MindSpore
import mindspore
from mindspore import nn

net = nn.Dense(2, 3)
optimizer = nn.RMSProp(net.trainable_params())
criterion = nn.MAELoss(reduction="mean")

def forward_fn(data, label):
    logits = net(data)
    loss = criterion(logits, label)
    return loss, logits

grad_fn = mindspore.value_and_grad(forward_fn, None, optimizer.parameters, has_aux=True)

def train_step(data, label):
    (loss, _), grads = grad_fn(data, label)
    optimizer(grads)
    return loss

# PyTorch
import torch

model = torch.nn.Linear(2, 3)
criterion = torch.nn.L1Loss(reduction='mean')
optimizer = torch.optim.RMSProp(model.parameters())
def train_step(data, label):
    optimizer.zero_grad()
    output = model(data)
    loss = criterion(output, label)
    loss.backward()
    optimizer.step()