import torch.nn as nn
import torch.nn.functional as F
__author__ = "Sachin Mehta"
class CrossEntropyLoss2d(nn.Module):
'''
This file defines a cross entropy loss for 2D images
'''
def __init__(self, weight=None):
'''
:param weight: 1D weight vector to deal with the class-imbalance
'''
super().__init__()
self.loss = nn.NLLLoss2d(weight)
def forward(self, outputs, targets):
return self.loss(F.log_softmax(outputs, 1), targets)