k.backward(p)的意思
时间: 2024-04-20 14:26:43 浏览: 9
k.backward(p)是PyTorch中一个用于计算梯度的方法。在神经网络训练中,我们通常需要计算损失函数关于网络参数的梯度,以便通过梯度下降等优化算法来更新网络参数。k.backward(p)表示计算变量k关于变量p的梯度,并将梯度累加到p的.grad属性中。这样做可以方便地对多个参数进行梯度累加或者实现更复杂的梯度计算逻辑。
相关问题
Runs MNIST training with differential privacy. """ Using matrix project to compress the gradient matrix """ def compress(grad, num_k, power_iter=1): return B, G_hat """ Complete the function of per-example clip """ def clip_column(tsr, clip_value=1.0): return def train(args, model, device, train_loader, optimizer, epoch, loss_func, clip_value): model.train() # criterion = nn.CrossEntropyLoss() losses = [] for _batch_idx, (data, target) in enumerate(tqdm(train_loader)): data, target = data.to(device), target.to(device) batch_grad_list = [] optimizer.zero_grad() output = model(data) loss = loss_func(output, target) if not args.disable_dp: with backpack(BatchGrad()): loss.backward() for p in model.parameters(): batch_grad_list.append(p.grad_batch.reshape(p.grad_batch.shape[0], -1)) #compose gradient into Matrix del p.grad_batch """ Using project method to compress the gradient """ if args.using_compress: #per-example clip else: """ Complete the code of DPSGD """ else: loss.backward() try: for p in model.parameters(): del p.grad_batch except: pass optimizer.step() losses.append(loss.item()) #get the num of the training dataset from train_loader if not args.disable_dp: epsilon = get_epsilon(epoch, delta=args.delta, sigma=args.sigma, sensitivity=clip_value, batch_size=args.batch_size, training_nums=len(train_loader)*args.batch_size) print( f"Train Epoch: {epoch} \t" f"Loss: {np.mean(losses):.6f} " f"(ε = {epsilon:.2f}, δ = {args.delta})" ) else: print(f"Train Epoch: {epoch} \t Loss: {np.mean(losses):.6f}")
这段代码是运行带有差分隐私的MNIST训练,其中使用矩阵项目压缩梯度矩阵。函数compress(grad, num_k, power_iter=1)用于压缩梯度矩阵,该函数返回B和G_hat。函数clip_column(tsr, clip_value=1.0)是用于每个样本的剪切函数,需要你完成代码。train函数是训练函数,其中loss_func是损失函数,clip_value是剪切值,如果不禁用差分隐私,则会计算epsilon值并打印。
Display the capital letters of the alphabet backward from Z to A.
Sure, here are the capital letters of the alphabet backward from Z to A:
Z, Y, X, W, V, U, T, S, R, Q, P, O, N, M, L, K, J, I, H, G, F, E, D, C, B, A.