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2025-03-20 21:40:01 -07:00

90 lines
3.0 KiB
Python

import os
import sys
import unittest
import torch
from torch import Tensor
from typing import List, Tuple
PROJECT_ROOT = os.path.realpath(os.path.join(os.path.dirname(__file__), "..", ".."))
MODULE_ROOT = os.path.join(PROJECT_ROOT, "modules")
sys.path.append(MODULE_ROOT)
from pytorch_wrapper.ptn_nll_loss import PtnNLLLoss
class TestPtnNLLLoss(unittest.TestCase):
def setUp(self) -> None:
"""
Set up the test instance by initializing the loss functions and test cases.
"""
self.node = PtnNLLLoss()
self.loss_fun_none = self.node.f("none")[0]
self.loss_fun_mean = self.node.f("mean")[0]
self.loss_fun_sum = self.node.f("sum")[0]
logits = torch.tensor([
[-2.0, -1.0, 0.0, 1.0, 2.0],
[-40.0, -20.0, 0.0, 10.0, 20.0]
], dtype=torch.float32)
log_probs = torch.nn.functional.log_softmax(logits, dim=1)
self.test_cases: List[Tuple[Tensor, Tensor]] = [
(
log_probs,
torch.tensor([0, 2], dtype=torch.int64)
)
]
def unreduced_loss(self, log_probs: Tensor, targets: Tensor) -> Tensor:
"""
Compute the unreduced negative log-likelihood loss.
Args:
log_probs (Tensor): Log-probabilities from log_softmax.
targets (Tensor): Ground truth class indices.
Returns:
Tensor: Unreduced element-wise NLL loss.
"""
return torch.nn.functional.nll_loss(log_probs, targets, reduction='none')
def test_none(self) -> None:
"""
Test NLL loss with reduction='none'.
"""
for log_probs, targets in self.test_cases:
with self.subTest(log_probs=log_probs):
expected = self.unreduced_loss(log_probs, targets)
actual = self.loss_fun_none(log_probs, targets)
self.assertTrue(torch.allclose(actual, expected, atol=1e-4),
f"Expected {expected}, got {actual}")
def test_mean(self) -> None:
"""
Test NLL loss with reduction='mean'.
"""
for log_probs, targets in self.test_cases:
with self.subTest(log_probs=log_probs):
loss = self.unreduced_loss(log_probs, targets)
expected = loss.mean(dim=0)
actual = self.loss_fun_mean(log_probs, targets)
self.assertTrue(torch.equal(actual, expected),
f"Expected {expected}, got {actual}")
def test_sum(self) -> None:
"""
Test NLL loss with reduction='sum'.
"""
for log_probs, targets in self.test_cases:
with self.subTest(log_probs=log_probs):
loss = self.unreduced_loss(log_probs, targets)
expected = loss.sum(dim=0)
actual = self.loss_fun_sum(log_probs, targets)
self.assertTrue(torch.equal(actual, expected),
f"Expected {expected}, got {actual}")
if __name__ == "__main__":
unittest.main()