Function Differences with torch.nn.LSTMCell

torch.nn.LSTMCell

class torch.nn.LSTMCell(
    input_size,
    hidden_size,
    bias=True)(input, h_0, c_0) -> Tensor

For more information, see torch.nn.LSTMCell.

mindspore.nn.LSTMCell

class mindspore.nn.LSTMCell(
    input_size,
    hidden_size,
    has_bias=True)(x, hx) -> Tensor

For more information, see mindspore.nn.LSTMCell.

Differences

PyTorch: Compute long-term and short-term memory network units.

MindSpore: MindSpore API basically implements the same function as PyTorch, but the return value differs in form. h_1 and c_1 are returned in PyTorch, while hx’ is returned in MindSpore, which is a tuple of two Tensors (h’, c ‘).

Categories	Subcategories	PyTorch	MindSpore	Difference
Parameters	Parameter 1	input_size	input_size	-
	Parameter 2	hidden_size	hidden_size	-
	Parameter 3	bias	has_bias	Same function, different parameter names
Inputs	Input 1	input	x	Same function, different parameter names
	Input 2	h_0	hx	In MindSpore hx represents a tuple of two Tensor(h_0, c_0), corresponding to inputs 2 and 3 in PyTorch, with the same function
	Input 3	c_0	hx	In MindSpore hx represents a tuple of two Tensor(h_0, c_0), corresponding to inputs 2 and 3 in PyTorch, with the same function

Code Example 1

LSTMCell input dimension is 10, hidden state dimension is 16, hidden layer is 3 rows and 16 columns matrix, cell is 3 rows and 20 columns matrix. 5 for loops compute the whole sequence sequentially, and the (hx,cx) of the current Cell is used as the hidden layer input for the next computation. The two APIs achieve the same function.

# PyTorch
import torch
from torch import tensor
import numpy as np

rnn = torch.nn.LSTMCell(10, 16)
input = tensor(np.ones([5, 3, 10]).astype(np.float32))
hx = tensor(np.ones([3, 16]).astype(np.float32))
cx = tensor(np.ones([3, 16]).astype(np.float32))
output = []
for i in range(input.size()[0]):
    hx, cx = rnn(input[i], (hx, cx))
    output.append(hx)
print(tuple(output[0].shape))
# (3, 16)

# MindSpore
import mindspore.nn as nn
from mindspore import Tensor
import numpy as np

net = nn.LSTMCell(10, 16)
x = Tensor(np.ones([5, 3, 10]).astype(np.float32))
h = Tensor(np.ones([3, 16]).astype(np.float32))
c = Tensor(np.ones([3, 16]).astype(np.float32))
output = []
for i in range(5):
    hx = net(x[i], (h, c))
    output.append(hx)
print(output[0][0].shape)
# (3, 16)

Code Example 2

When bias=False, without bias b_ih and b_hh. The layer does not use offset weights and the two APIs achieve the same function.

# PyTorch
import torch
from torch import tensor
import numpy as np

rnn = torch.nn.LSTMCell(10, 16, bias=False)
input = tensor(np.ones([5, 3, 10]).astype(np.float32))
hx = tensor(np.ones([3, 16]).astype(np.float32))
cx = tensor(np.ones([3, 16]).astype(np.float32))
output = []
for i in range(input.size()[0]):
    hx, cx = rnn(input[i], (hx, cx))
    output.append(hx)
print(tuple(output[0].shape))
# (3, 16)

# MindSpore
import mindspore.nn as nn
from mindspore import Tensor
import numpy as np

net = nn.LSTMCell(10, 16, has_bias=False)
x = Tensor(np.ones([5, 3, 10]).astype(np.float32))
h = Tensor(np.ones([3, 16]).astype(np.float32))
c = Tensor(np.ones([3, 16]).astype(np.float32))
output = []
for i in range(5):
    hx = net(x[i], (h, c))
    output.append(hx)
print(output[0][0].shape)
# (3, 16)