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import numpy as np | |
import torch | |
import torch.nn.functional as F | |
def cal_loss(pred, gold, smoothing=True): | |
''' Calculate cross entropy loss, apply label smoothing if needed. ''' | |
gold = gold.contiguous().view(-1) # gold is the groudtruth label in the dataloader | |
if smoothing: | |
eps = 0.2 | |
n_class = pred.size(1) # the number of feature_dim of the ouput, which is output channels | |
one_hot = torch.zeros_like(pred).scatter(1, gold.view(-1, 1), 1) | |
one_hot = one_hot * (1 - eps) + (1 - one_hot) * eps / (n_class - 1) | |
log_prb = F.log_softmax(pred, dim=1) | |
loss = -(one_hot * log_prb).sum(dim=1).mean() | |
else: | |
loss = F.cross_entropy(pred, gold, reduction='mean') | |
return loss | |
# create a file and write the text into it: | |
class IOStream(): | |
def __init__(self, path): | |
self.f = open(path, 'a') | |
def cprint(self, text): | |
print(text) | |
self.f.write(text+'\n') | |
self.f.flush() | |
def close(self): | |
self.f.close() | |
def to_categorical(y, num_classes): | |
""" 1-hot encodes a tensor """ | |
new_y = torch.eye(num_classes)[y.cpu().data.numpy(),] | |
if (y.is_cuda): | |
return new_y.cuda(non_blocking=True) | |
return new_y | |
def compute_overall_iou(pred, target, num_classes): | |
shape_ious = [] | |
pred = pred.max(dim=2)[1] # (batch_size, num_points) the pred_class_idx of each point in each sample | |
pred_np = pred.cpu().data.numpy() | |
target_np = target.cpu().data.numpy() | |
for shape_idx in range(pred.size(0)): # sample_idx | |
part_ious = [] | |
for part in range(num_classes): # class_idx! no matter which category, only consider all part_classes of all categories, check all 50 classes | |
# for target, each point has a class no matter which category owns this point! also 50 classes!!! | |
# only return 1 when both belongs to this class, which means correct: | |
I = np.sum(np.logical_and(pred_np[shape_idx] == part, target_np[shape_idx] == part)) | |
# always return 1 when either is belongs to this class: | |
U = np.sum(np.logical_or(pred_np[shape_idx] == part, target_np[shape_idx] == part)) | |
F = np.sum(target_np[shape_idx] == part) | |
if F != 0: | |
iou = I / float(U) # iou across all points for this class | |
part_ious.append(iou) # append the iou of this class | |
shape_ious.append(np.mean(part_ious)) # each time append an average iou across all classes of this sample (sample_level!) | |
return shape_ious # [batch_size] | |