问题
The following is a Feed-forward network using the nn.functional() module in PyTorch
import torch.nn as nn
import torch.nn.functional as F
class newNetwork(nn.Module):
def __init__(self):
super().__init__()
self.fc1 = nn.Linear(784, 128)
self.fc2 = nn.Linear(128, 64)
self.fc3 = nn.Linear(64,10)
def forward(self,x):
x = F.relu(self.fc1(x))
x = F.relu(self.fc2(x))
x = F.softmax(self.fc3(x))
return x
model = newNetwork()
model
The following is the same Feed-forward using nn.sequential() module to essentially build the same thing. What is the difference between the two and when would i use one instead of the other?
input_size = 784
hidden_sizes = [128, 64]
output_size = 10
Build a feed-forward network
model = nn.Sequential(nn.Linear(input_size, hidden_sizes[0]),
nn.ReLU(),
nn.Linear(hidden_sizes[0], hidden_sizes[1]),
nn.ReLU(),
nn.Linear(hidden_sizes[1], output_size),
nn.Softmax(dim=1))
print(model)
回答1:
There is no difference between the two. The latter is arguably more concise and easier to write and the reason for "objective" versions of pure (ie non-stateful) functions like ReLU and Sigmoid is to allow their use in constructs like nn.Sequential.
来源:https://stackoverflow.com/questions/53745454/are-there-any-computational-efficiency-differences-between-nn-functional-vs-nn