import torch

y_pred = torch.tensor([
    [1, 1, 0, 1, 1, 1]
    ], dtype=torch.float)

y_truth_id = torch.tensor([2], dtype=torch.long)
y_truth_id_tmp  = y_truth_id.unsqueeze(0)
y_truth_one_hot = torch.zeros(y_truth_id_tmp.size(0), 6).scatter_(1, y_truth_id_tmp, 1.)

criterion_2 =  torch.nn.BCELoss()
res_2 = criterion_2(y_pred, y_truth_one_hot)
print('BCELoss: ', res_2)

# output: BCELoss:  tensor(27.6310)