optimizer = optim.Adam(classifier.parameters(), lr=0.001, betas=(0.9, 0.999))
scheduler = optim.lr_scheduler.StepLR(optimizer, step_size=20, gamma=0.5)
classifier.cuda()
num_batch = len(dataset) / opt.batchSize
for epoch in range(opt.nepoch):
scheduler.step()
for i, data in enumerate(dataloader, 0):
points, target = data
target = target[:, 0]
points = points.transpose(2, 1)
points, target = points.cuda(), target.cuda()
optimizer.zero_grad()
classifier = classifier.train()
pred, trans, trans_feat = classifier(points)
loss = F.nll_loss(pred, target)
if opt.feature_transform:
loss += feature_transform_regularizer(trans_feat) * 0.001
loss.backward()
optimizer.step()
pred_choice = pred.data.max(1)[1]
correct = pred_choice.eq(target.data).cpu().sum()
print('[%d: %d/%d] train loss: %f accuracy: %f' %
(epoch, i, num_batch, loss.item(),
correct.item() / float(opt.batchSize)))
if i % 10 == 0:
j, data = next(enumerate(testdataloader, 0))
points, target = data
def our_main():
from utils.show3d_balls import showpoints
parser = argparse.ArgumentParser()
parser.add_argument(
'--batchSize', type=int, default=32, help='input batch size')
parser.add_argument(
'--num_points', type=int, default=2000, help='input batch size')
parser.add_argument(
'--workers', type=int, help='number of data loading workers', default=4)
parser.add_argument(
'--nepoch', type=int, default=250, help='number of epochs to train for')
parser.add_argument('--outf', type=str, default='cls', help='output folder')
parser.add_argument('--model', type=str, default='', help='model path')
parser.add_argument('--dataset', type=str, required=True, help="dataset path")
parser.add_argument('--dataset_type', type=str, default='shapenet', help="dataset type shapenet|modelnet40")
parser.add_argument('--feature_transform', action='store_true', help="use feature transform")
opt = parser.parse_args()
print(opt)
blue = lambda x: '\033[94m' + x + '\033[0m'
opt.manualSeed = random.randint(1, 10000) # fix seed
print("Random Seed: ", opt.manualSeed)
random.seed(opt.manualSeed)
torch.manual_seed(opt.manualSeed)
if opt.dataset_type == 'shapenet':
dataset = ShapeNetDataset(
root=opt.dataset,
classification=True,
npoints=opt.num_points)
test_dataset = ShapeNetDataset(
root=opt.dataset,
classification=True,
split='test',
npoints=opt.num_points,
data_augmentation=False)
elif opt.dataset_type == 'modelnet40':
dataset = ModelNetDataset(
root=opt.dataset,
npoints=opt.num_points,
split='trainval')
test_dataset = ModelNetDataset(
root=opt.dataset,
split='test',
npoints=opt.num_points,
data_augmentation=False)
else:
exit('wrong dataset type')
dataloader = torch.utils.data.DataLoader(
dataset,
batch_size=opt.batchSize,
shuffle=True,
num_workers=int(opt.workers))
testdataloader = torch.utils.data.DataLoader(
test_dataset,
batch_size=opt.batchSize,
shuffle=True,
num_workers=int(opt.workers))
print(len(dataset), len(test_dataset))
num_classes = len(dataset.classes)
print('classes', num_classes)
try:
os.makedirs(opt.outf)
except OSError:
pass
classifier = PointNetCls(k=num_classes, feature_transform=opt.feature_transform)
if opt.model != '':
classifier.load_state_dict(torch.load(opt.model))
optimizer = optim.Adam(classifier.parameters(), lr=0.001, betas=(0.9, 0.999))
scheduler = optim.lr_scheduler.StepLR(optimizer, step_size=20, gamma=0.5)
classifier.cuda()
num_batch = len(dataset) / opt.batchSize
## python train_classification.py --dataset ../dataset --nepoch=4 --dataset_type shapenet
for epoch in range(opt.nepoch):
scheduler.step()
for i, data in enumerate(dataloader, 0):
points, target = data
target = target[:, 0]
showpoints(points[0].numpy())
points = points.transpose(2, 1)
points, target = points.cuda(), target.cuda()
optimizer.zero_grad()
classifier = classifier.train()
pred, trans, trans_feat = classifier(points)
loss = F.nll_loss(pred, target)
if opt.feature_transform:
loss += feature_transform_regularizer(trans_feat) * 0.001
loss.backward()
optimizer.step()
pred_choice = pred.data.max(1)[1]
correct = pred_choice.eq(target.data).cpu().sum()
print('[%d: %d/%d] train loss: %f accuracy: %f' % (epoch, i, num_batch, loss.item(), correct.item() / float(opt.batchSize)))
if i % 10 == 0:
j, data = next(enumerate(testdataloader, 0))
points, target = data
target = target[:, 0]
points = points.transpose(2, 1)
points, target = points.cuda(), target.cuda()
classifier = classifier.eval()
pred, _, _ = classifier(points)
loss = F.nll_loss(pred, target)
pred_choice = pred.data.max(1)[1]
correct = pred_choice.eq(target.data).cpu().sum()
print('[%d: %d/%d] %s loss: %f accuracy: %f' % (epoch, i, num_batch, blue('test'), loss.item(), correct.item()/float(opt.batchSize)))
torch.save(classifier.state_dict(), '%s/cls_model_%d.pth' % (opt.outf, epoch))
total_correct = 0
total_testset = 0
for i,data in tqdm(enumerate(testdataloader, 0)):
points, target = data
target = target[:, 0]
points = points.transpose(2, 1)
points, target = points.cuda(), target.cuda()
classifier = classifier.eval()
pred, _, _ = classifier(points)
pred_choice = pred.data.max(1)[1]
correct = pred_choice.eq(target.data).cpu().sum()
total_correct += correct.item()
total_testset += points.size()[0]
print("final accuracy {}".format(total_correct / float(total_testset)))
# Moves all model parameters and buffers to the GPU.
classifier.cuda()
num_batch = len(dataset) / opt.batchSize # 计算batch的数量
for epoch in range(opt.nepoch):
scheduler.step()
# 将一个可遍历对象组合为一个索引序列，同时列出数据和数据下标,(0, seq[0])...
# __init__(self, iterable, start=0)，参数为可遍历对象及起始位置
for i, data in enumerate(dataloader, 0):
points, target = data
target = target[:, 0] # 取所有行的第0列
points = points.transpose(2, 1) # 维度交换
points, target = points.cuda(), target.cuda() # tensor转到cuda上
optimizer.zero_grad() # 梯度清除，避免backward时梯度累加
classifier = classifier.train() # 训练模式，使能BN和dropout
pred, trans, trans_feat = classifier(points) # 网络结果预测输出
loss = F.nll_loss(
pred, target) # 损失函数：负log似然损失，在分类网络中使用了log_softmax，二者结合其实就是交叉熵损失函数
if opt.feature_transform:
loss += feature_transform_regularizer(trans_feat) * 0.001
loss.backward() # loss反向传播
optimizer.step() # 梯度下降，参数优化
pred_choice = pred.data.max(1)[1] # max(1)返回每一行中的最大值及索引,[1]取出索引（代表着类别）
correct = pred_choice.eq(
target.data).cpu().sum() # 判断和target是否匹配，并计算匹配的数量
print('[%d: %d/%d] train loss: %f accuracy: %f' %
(epoch, i, num_batch, loss.item(),
correct.item() / float(opt.batchSize)))
# 每10次batch之后，进行一次测试
print(len(dataset)) # 12137的训练数据集的迭代器, 每个迭代器32个3维模型 相当于dataset中一共读入了12137*32=388384个三维模型
num_batch = len(dataset) / opt.batchSize # 所以每次参与训练的迭代器数量为 12137 / 32= 379.28个迭代器, 三维模型为 379*32=12128
print('num_batch: %d' % (num_batch))
# 5. 正式开始训练
for epoch in range(opt.nepoch): # opt.nepoch = 5, 训练5次
scheduler.step() # 更新一下学习率 每step_size=20 调整一次
# n = 0
for i, data in enumerate(dataloader, 0): # enumerate在字典上是枚举、列举的意思, enumerate参数为可遍历/可迭代的对象(如列表、字符串), 后面的0是索引从0开始
points, target = data
target = target[:, 0]
points = points.transpose(2, 1)
points, target = points.cuda(), target.cuda() # 复制到cuda上进行计算
optimizer.zero_grad() # 梯度清零，等价于net.zero_grad()
classifier = classifier.train() # 模型设置为训练模式
pred, trans, trans_feat = classifier(points)
# print(pred.shape) torch.Size([32, 16])
loss = F.nll_loss(pred, target) # 使用nll_loss损失函数, 传入预测的分数矩阵和真实标签值target, nll损失函数的计算方法见：https://blog.csdn.net/qq_22210253/article/details/85229988
if opt.feature_transform:
loss += feature_transform_regularizer(trans_feat) * 0.001
loss.backward() # 小批量的损失对模型参数求梯度
optimizer.step() # 梯度下降优化 以batch为单位, 通过调用optim实例的step函数来迭代模型参数, w, b
pred_choice = pred.data.max(1)[1]
correct = pred_choice.eq(target.data).cpu().sum().item()
# n += target.shape[0]
print('[%d: %d/%d] train loss: %f accuracy: %f' % (epoch, i, num_batch, loss.item(), correct / float(opt.batchSize)))
if i % 10 == 0: # 每10个batch执行一次,即为每10*batchSize个点云执行一次验证
j, data = next(enumerate(testdataloader, 0))
points, target = data