def train(hyp):
    cfg = opt.cfg
    # data = opt.data
    epochs = opt.epochs  # 500200 batches at bs 64, 117263 images = 273 epochs
    batch_size = opt.batch_size
    accumulate = max(round(64 / batch_size),
                     1)  # accumulate n times before optimizer update (bs 64)
    weights = opt.weights  # initial training weights
    # Image Sizes
    gs = 32  # (pixels) grid size max stride
    # Configure run
    init_seeds()
    nc = 1 if opt.single_cls else int(len(open(
        opt.names_classes).readlines()))  # number of classes
    hyp['cls'] *= nc / 80  # update coco-tuned hyp['cls'] to current dataset

    # Remove previous results
    for f in glob.glob('*_batch*.jpg') + glob.glob(results_file):
        os.remove(f)

    # Initialize model
    # model = Darknet(opt.cfg, opt.input_size, opt.algorithm_type).to(device)
    from utils.model_prune import Darknet_sss
    model = Darknet_sss(opt.cfg, opt.input_size, opt.algorithm_type).to(device)
    CBL_idx, _, prune_idx, ignore_idx = parse_module_defs(model.module_defs)
    # Optimizer
    pg0, pg1, pg2 = [], [], []  # optimizer parameter groups
    for k, v in dict(model.named_parameters()).items():
        if '.bias' in k:
            pg2 += [v]  # biases
        elif 'Conv2d.weight' in k:
            pg1 += [v]  # apply weight_decay
        else:
            pg0 += [v]  # all else

    if opt.adam:
        # hyp['lr0'] *= 0.1  # reduce lr (i.e. SGD=5E-3, Adam=5E-4)
        optimizer = optim.Adam(pg0, lr=hyp['lr0'])
        # optimizer = AdaBound(pg0, lr=hyp['lr0'], final_lr=0.1)
    else:
        optimizer = optim.SGD(pg0,
                              lr=hyp['lr0'],
                              momentum=hyp['momentum'],
                              nesterov=True)
    if opt.sss:
        optimizer2 = APGNAG([{
            'params': model.lambda_block
        }],
                            lr=hyp['lr0'],
                            momentum=opt.momentum,
                            gamma=opt.gamma_data)
    optimizer.add_param_group({
        'params': pg1,
        'weight_decay': hyp['weight_decay']
    })  # add pg1 with weight_decay
    optimizer.add_param_group({'params': pg2})  # add pg2 (biases)
    print('Optimizer groups: %g .bias, %g Conv2d.weight, %g other' %
          (len(pg2), len(pg1), len(pg0)))
    del pg0, pg1, pg2

    start_epoch = 0
    best_fitness = 0.0
    # attempt_download(weights)
    if weights.endswith('.pt'):  # pytorch format
        # possible weights are '*.pt', 'yolov3-spp.pt', 'yolov3-tiny.pt' etc.
        ckpt = torch.load(weights, map_location=device)

        # load model
        try:
            # ckpt['model'] = {k: v for k, v in ckpt['model'].state_dict().items() if model.state_dict()[k].numel() == v.numel()}
            # model.load_state_dict(ckpt['model'], strict=False)
            model.load_state_dict(
                torch.load(opt.weights, map_location=device)['model'])
        except KeyError as e:
            s = "%s is not compatible with %s. Specify --weights '' or specify a --cfg compatible with %s. " \
                "See https://github.com/ultralytics/yolov3/issues/657" % (opt.weights, opt.cfg, opt.weights)
            raise KeyError(s) from e

        # load optimizer
        # if ckpt['optimizer'] is not None:
        #     optimizer.load_state_dict(ckpt['optimizer'])
        #     best_fitness = ckpt['best_fitness']
        best_fitness = 1e-5

        # load results
        if ckpt.get('training_results') is not None:
            with open(results_file, 'w') as file:
                file.write(ckpt['training_results'])  # write results.txt

        # epochs
        start_epoch = ckpt['epoch'] + 1
        if epochs < start_epoch:
            print(
                '%s has been trained for %g epochs. Fine-tuning for %g additional epochs.'
                % (opt.weights, ckpt['epoch'], epochs))
            epochs += ckpt['epoch']  # finetune additional epochs

        del ckpt

    elif len(weights) > 0:  # darknet format
        # possible weights are '*.weights', 'yolov3-tiny.conv.15',  'darknet53.conv.74' etc.
        load_darknet_weights(model, weights)

    if opt.freeze_layers:
        output_layer_indices = [
            idx - 1 for idx, module in enumerate(model.module_list)
            if isinstance(module, YOLOLayer)
        ]
        freeze_layer_indices = [
            x for x in range(len(model.module_list))
            if (x not in output_layer_indices) and (
                x - 1 not in output_layer_indices)
        ]
        for idx in freeze_layer_indices:
            for parameter in model.module_list[idx].parameters():
                parameter.requires_grad_(False)

    # Mixed precision training https://github.com/NVIDIA/apex
    if mixed_precision:
        model, optimizer = amp.initialize(model,
                                          optimizer,
                                          opt_level='O1',
                                          verbosity=0)

    # Scheduler https://arxiv.org/pdf/1812.01187.pdf
    lf = lambda x: ((
        (1 + math.cos(x * math.pi / epochs)) / 2)**1.0) * 0.95 + 0.05  # cosine
    scheduler = lr_scheduler.LambdaLR(optimizer, lr_lambda=lf)
    scheduler.last_epoch = start_epoch - 1  # see link below
    if opt.sss:
        scheduler2 = lr_scheduler.LambdaLR(optimizer2, lr_lambda=lf)
        scheduler2.last_epoch = start_epoch - 1  # see link below
    # https://discuss.pytorch.org/t/a-problem-occured-when-resuming-an-optimizer/28822

    # Plot lr schedule
    # y = []
    # for _ in range(epochs):
    #     scheduler.step()
    #     y.append(optimizer.param_groups[0]['lr'])
    # plt.plot(y, '.-', label='LambdaLR')
    # plt.xlabel('epoch')
    # plt.ylabel('LR')
    # plt.tight_layout()
    # plt.savefig('LR.png', dpi=300)

    model = torch.nn.DataParallel(model).to(device)
    model.yolo_layers = model.module.yolo_layers  # move yolo layer indices to top level
    dataloader, dataset = create_dataloader(
        opt.train_path,
        opt.input_size,
        batch_size,
        gs,
        hyp=hyp,
        augment=True,
        cache=False,
        rect=False,
        local_rank=-1,  # Model parameters
        world_size=1)
    testloader = create_dataloader(opt.val_path,
                                   opt.input_size,
                                   4,
                                   gs,
                                   hyp=hyp,
                                   augment=False,
                                   cache=False,
                                   rect=True,
                                   local_rank=-1,
                                   world_size=1)[0]
    nw = 8
    model.nc = nc  # attach number of classes to model
    model.hyp = hyp  # attach hyperparameters to model
    model.gr = 1.0  # giou loss ratio (obj_loss = 1.0 or giou)
    model.class_weights = labels_to_class_weights(dataset.labels, nc).to(
        device)  # attach class weights
    model.module_list = model.module.module_list
    # Model EMA
    ema = torch_utils.ModelEMA(model)

    # Start training
    nb = len(dataloader)  # number of batches
    n_burn = max(3 * nb,
                 500)  # burn-in iterations, max(3 epochs, 500 iterations)
    maps = np.zeros(nc)  # mAP per class
    # torch.autograd.set_detect_anomaly(True)
    results = (
        0, 0, 0, 0, 0, 0, 0
    )  # 'P', 'R', 'mAP', 'F1', 'val GIoU', 'val Objectness', 'val Classification'
    t0 = time.time()
    # print('Image sizes %g - %g train, %g test' % (imgsz_min, imgsz_max, imgsz_test))
    print('Using %g dataloader workers' % nw)
    print('Starting training for %g epochs...' % epochs)
    start_epoch = 0
    for epoch in range(
            start_epoch, epochs
    ):  # epoch ------------------------------------------------------------------
        model.train()
        # Update image weights (optional)
        if dataset.image_weights:
            w = model.class_weights.cpu().numpy() * (1 -
                                                     maps)**2  # class weights
            image_weights = labels_to_image_weights(dataset.labels,
                                                    nc=nc,
                                                    class_weights=w)
            dataset.indices = random.choices(range(dataset.n),
                                             weights=image_weights,
                                             k=dataset.n)  # rand weighted idx

        mloss = torch.zeros(4).to(device)  # mean losses
        print(('\n' + '%10s' * 8) % ('Epoch', 'gpu_mem', 'GIoU', 'obj', 'cls',
                                     'total', 'targets', 'img_size'))
        pbar = tqdm(enumerate(dataloader), total=nb)  # progress bar
        for i, (
                imgs, targets, paths, _
        ) in pbar:  # batch -------------------------------------------------------------
            # for i, (imgs, targets, paths, _) in enumerate(dataloader):  # batch -------------------------------------------------------------
            ni = i + nb * epoch  # number integrated batches (since train start)
            imgs = imgs.to(device).float(
            ) / 255.0  # uint8 to float32, 0 - 255 to 0.0 - 1.0
            if opt.multi_scale:
                sz = random.randrange(
                    opt.input_size * 0.5,
                    opt.input_size * 1.5 + gs) // gs * gs  # size
                sf = sz / max(imgs.shape[2:])  # scale factor
                if sf != 1:
                    ns = [math.ceil(x * sf / gs) * gs for x in imgs.shape[2:]
                          ]  # new shape (stretched to gs-multiple)
                    imgs = F.interpolate(imgs,
                                         size=ns,
                                         mode='bilinear',
                                         align_corners=False)
            targets = targets.to(device)

            # Burn-in
            if ni <= n_burn:
                xi = [0, n_burn]  # x interp
                model.gr = np.interp(
                    ni, xi,
                    [0.0, 1.0])  # giou loss ratio (obj_loss = 1.0 or giou)
                accumulate = max(
                    1,
                    np.interp(ni, xi, [1, 64 / batch_size]).round())
                for j, x in enumerate(optimizer.param_groups):
                    # bias lr falls from 0.1 to lr0, all other lrs rise from 0.0 to lr0
                    x['lr'] = np.interp(
                        ni, xi,
                        [0.1 if j == 2 else 0.0, x['initial_lr'] * lf(epoch)])
                    x['weight_decay'] = np.interp(
                        ni, xi, [0.0, hyp['weight_decay'] if j == 1 else 0.0])
                    if 'momentum' in x:
                        x['momentum'] = np.interp(ni, xi,
                                                  [0.9, hyp['momentum']])
            # Forward
            # if opt.sss:
            pred = model(imgs)
            # else:
            #     pred = model(imgs)
            # Loss
            loss, loss_items = compute_loss(pred, targets, model)
            if not torch.isfinite(loss):
                print('WARNING: non-finite loss, ending training ', loss_items)
                return results
            # Backward
            loss *= batch_size / 64  # scale loss
            if mixed_precision:
                with amp.scale_loss(loss, optimizer) as scaled_loss:
                    scaled_loss.backward()
            else:
                loss.backward()
            # Optimize
            idx2mask = None
            # if opt.sr and opt.prune==1 and epoch > opt.epochs * 0.5:
            #     idx2mask = get_mask2(model, prune_idx, 0.85)

            # BNOptimizer.updateBN(opt.sr_flag, model.module_list, opt.gamma, prune_idx, idx2mask)
            if ni % accumulate == 0:
                optimizer.step()
                optimizer.zero_grad()
                if opt.sss:
                    optimizer2.step()
                    optimizer2.zero_grad()
                ema.update(model)

            # Print
            mloss = (mloss * i + loss_items) / (i + 1)  # update mean losses
            mem = '%.3gG' % (torch.cuda.memory_cached() /
                             1E9 if torch.cuda.is_available() else 0)  # (GB)
            s = ('%10s' * 2 + '%10.3g' * 6) % (
                '%g/%g' %
                (epoch, epochs - 1), mem, *mloss, len(targets), imgs.shape[-1])
            pbar.set_description(s)

            # Plot
            if ni < 1:
                f = 'train_batch%g.jpg' % i  # filename
                res = plot_images(images=imgs,
                                  targets=targets,
                                  paths=paths,
                                  fname=f)
                if tb_writer:
                    tb_writer.add_image(f,
                                        res,
                                        dataformats='HWC',
                                        global_step=epoch)
                    # tb_writer.add_graph(model, imgs)  # add model to tensorboard
            # end batch ------------------------------------------------------------------------------------------------
        # Update scheduler
        scheduler.step()
        # Process epoch results
        ema.update_attr(model)
        final_epoch = epoch + 1 == epochs
        if not opt.notest or final_epoch:  # Calculate mAP
            results, maps, times = test.test(
                cfg=opt.cfg,
                names_file=opt.names_classes,
                batch_size=8,
                img_size=opt.input_size,
                conf_thres=0.01,
                save_json=False,
                # model=ema.ema.module if hasattr(ema.ema, 'module') else ema.ema,
                model=ema.ema,
                single_cls=False,
                dataloader=testloader,
                save_dir=wdir)
        if opt.sss:
            print("lambda '{}'\n".format(model.module.lambda_block if hasattr(
                model, 'module') else model.lambda_block))
        if epoch % opt.interval_prune == 0:
            #------------------------------  begin soft prune ---------------------------------------------#
            obtain_num_parameters = lambda model: sum(
                [param.nelement() for param in model.parameters()])
            origin_nparameters = obtain_num_parameters(model)
            from utils.prune_utils import parse_module_defs2, get_global_norm_thr, obtain_filters_mask_norm, merge_mask, prune_soft_model_code, get_layer_norm_thr, obtain_filters_mask_norm_per_layer
            CBL_idx, Conv_idx, prune_idx, _, _ = parse_module_defs2(
                model.module.module_defs if hasattr(model, 'module'
                                                    ) else model.module_defs)
            # norm_thr = get_global_norm_thr(model, prune_idx, opt.global_percent)
            norm_thr_list, norm_prune_index = get_layer_norm_thr(
                model, prune_idx, opt.global_percent)
            print("norm_thr_list is", norm_thr_list)
            # print("norm index is", norm_prune_index)
            num_filters_l2, filters_mask_l2 = obtain_filters_mask_norm_per_layer(
                model,
                norm_thr_list,
                CBL_idx,
                prune_idx,
                layer_keep=opt.layer_keep)
            CBLidx2mask = {
                idx: mask
                for idx, mask in zip(CBL_idx, filters_mask_l2)
            }
            CBLidx2filters = {
                idx: filters
                for idx, filters in zip(CBL_idx, num_filters_l2)
            }
            for i in model.module.module_defs if hasattr(
                    model, 'module') else model.module_defs:
                if i['type'] == 'shortcut':
                    i['is_access'] = False
            # print('merge the mask of layers connected to shortcut!')
            merge_mask(model.module if hasattr(model, 'module') else model,
                       CBLidx2mask, CBLidx2filters)
            prune_soft_model_code(
                model.module if hasattr(model, 'module') else model, CBL_idx,
                CBLidx2mask)
            print("after soft prune, map test ")
            results_sfp, maps_sfp, times_sfp = test.test(
                cfg=opt.cfg,
                names_file=opt.names_classes,
                batch_size=8,
                img_size=opt.input_size,
                conf_thres=0.01,
                save_json=False,
                model=model.module if hasattr(model, 'module') else model,
                single_cls=False,
                dataloader=testloader,
                save_dir=wdir)

        # Write
        with open(results_file, 'a') as f:
            f.write(s + '%10.3g' * 7 % results +
                    '\n')  # P, R, mAP, F1, test_losses=(GIoU, obj, cls)
        if len(opt.name) and opt.bucket:
            os.system('gsutil cp results.txt gs://%s/results/results%s.txt' %
                      (opt.bucket, opt.name))

        # Tensorboard
        if tb_writer:
            tags = [
                'train/giou_loss', 'train/obj_loss', 'train/cls_loss',
                'metrics/precision', 'metrics/recall', 'metrics/mAP_0.5',
                'metrics/F1', 'val/giou_loss', 'val/obj_loss', 'val/cls_loss'
            ]
            for x, tag in zip(list(mloss[:-1]) + list(results), tags):
                tb_writer.add_scalar(tag, x, epoch)
            bn_weights = gather_bn_weights(model.module_list, prune_idx)
            tb_writer.add_histogram('bn_weights/hist',
                                    bn_weights.numpy(),
                                    epoch,
                                    bins='doane')
        # Update best mAP
        fi = fitness(np.array(results).reshape(
            1, -1))  # fitness_i = weighted combination of [P, R, mAP, F1]
        # fisfp = fitness(np.array(results_sfp).reshape(1, -1))  # fitness_i = weighted combination of [P, R, mAP, F1]
        # if fi-fisfp < 0.05:
        #     with open(results_file, 'r') as f:  # create checkpoint
        #         ckpt = {'epoch': epoch,
        #                 'best_fitness': str(fisfp),
        #                 'training_results': f.read(),
        #                 # 'model': ema.ema.module.state_dict() if hasattr(model, 'module') else ema.ema.state_dict(),
        #                 'model': ema.ema.module if hasattr(ema, 'module') else ema.ema,
        #                 'optimizer': None if final_epoch else optimizer.state_dict()}
        #         torch.save(ckpt, last)
        #         if (best_fitness == fi) and not final_epoch:
        #             torch.save(ckpt, best)
        #         del ckpt
        if fi > best_fitness:
            best_fitness = fi

        # Save model
        save = (not opt.nosave) or (final_epoch and not opt.evolve)
        if save:
            with open(results_file, 'r') as f:  # create checkpoint
                ckpt = {
                    'epoch': epoch,
                    'best_fitness': best_fitness,
                    'training_results': f.read(),
                    # 'model': ema.ema.module.state_dict() if hasattr(model, 'module') else ema.ema.state_dict(),
                    'model':
                    ema.ema.module if hasattr(ema, 'module') else ema.ema,
                    'optimizer':
                    None if final_epoch else optimizer.state_dict()
                }

            # Save last, best and delete
            torch.save(ckpt, last)
            if (best_fitness == fi) and not final_epoch:
                torch.save(ckpt, best)
            del ckpt

        # end epoch ----------------------------------------------------------------------------------------------------
    # end training

    n = opt.name
    if len(n):
        n = '_' + n if not n.isnumeric() else n
        fresults, flast, fbest = 'results%s.txt' % n, wdir + 'last%s.pt' % n, wdir + 'best%s.pt' % n
        for f1, f2 in zip([wdir + 'last.pt', wdir + 'best.pt', 'results.txt'],
                          [flast, fbest, fresults]):
            if os.path.exists(f1):
                os.rename(f1, f2)  # rename
                ispt = f2.endswith('.pt')  # is *.pt
                strip_optimizer(f2) if ispt else None  # strip optimizer
                os.system('gsutil cp %s gs://%s/weights' % (
                    f2, opt.bucket)) if opt.bucket and ispt else None  # upload

    if not opt.evolve:
        plot_results()  # save as results.png
    print('%g epochs completed in %.3f hours.\n' % (epoch - start_epoch + 1,
                                                    (time.time() - t0) / 3600))
    dist.destroy_process_group() if torch.cuda.device_count() > 1 else None
    torch.cuda.empty_cache()
    return results
Exemple #2
0
def train(hyp, opt, device, tb_writer=None, wandb=None):
    logger.info(f'Hyperparameters {hyp}')
    save_dir, epochs, batch_size, total_batch_size, weights, rank = \
        Path(opt.save_dir), opt.epochs, opt.batch_size, opt.total_batch_size, opt.weights, opt.global_rank

    # Directories
    wdir = save_dir / 'weights'
    wdir.mkdir(parents=True, exist_ok=True)  # make dir
    last = wdir / 'last.pt'
    best = wdir / 'best.pt'
    results_file = save_dir / 'results.txt'

    # Save run settings
    with open(save_dir / 'hyp.yaml', 'w') as f:
        yaml.dump(hyp, f, sort_keys=False)
    with open(save_dir / 'opt.yaml', 'w') as f:
        yaml.dump(vars(opt), f, sort_keys=False)

    # Configure
    plots = not opt.evolve  # create plots
    cuda = device.type != 'cpu'
    init_seeds(2 + rank)
    with open(opt.data) as f:
        data_dict = yaml.load(f, Loader=yaml.FullLoader)  # data dict
    with torch_distributed_zero_first(rank):
        check_dataset(data_dict)  # check
    train_path = data_dict['train']
    test_path = data_dict['val']
    nc = 1 if opt.single_cls else int(data_dict['nc'])  # number of classes
    names = ['item'] if opt.single_cls and len(
        data_dict['names']) != 1 else data_dict['names']  # class names
    assert len(names) == nc, '%g names found for nc=%g dataset in %s' % (
        len(names), nc, opt.data)  # check

    # Model
    pretrained = weights.endswith('.pt')
    if pretrained:
        # with torch_distributed_zero_first(rank):
        #     attempt_download(weights)  # download if not found locally
        ckpt = torch.load(weights, map_location=device)  # load checkpoint
        if hyp.get('anchors'):
            ckpt['model'].yaml['anchors'] = round(
                hyp['anchors'])  # force autoanchor
        model = Model(opt.cfg or ckpt['model'].yaml, ch=3,
                      nc=nc).to(device)  # create
        exclude = ['anchor'] if opt.cfg or hyp.get('anchors') else [
        ]  # exclude keys
        state_dict = ckpt['model'].float().state_dict()  # to FP32
        state_dict = intersect_dicts(state_dict,
                                     model.state_dict(),
                                     exclude=exclude)  # intersect
        model.load_state_dict(state_dict, strict=False)  # load
        logger.info(
            'Transferred %g/%g items from %s' %
            (len(state_dict), len(model.state_dict()), weights))  # report
    else:
        model = Model(opt.cfg, ch=3, nc=nc).to(device)  # create

    # Freeze
    freeze = []  # parameter names to freeze (full or partial)
    for k, v in model.named_parameters():
        v.requires_grad = True  # train all layers
        if any(x in k for x in freeze):
            print('freezing %s' % k)
            v.requires_grad = False

    # Optimizer
    nbs = 64  # nominal batch size
    accumulate = max(round(nbs / total_batch_size),
                     1)  # accumulate loss before optimizing
    hyp['weight_decay'] *= total_batch_size * accumulate / nbs  # scale weight_decay
    logger.info(f"Scaled weight_decay = {hyp['weight_decay']}")

    pg0, pg1, pg2 = [], [], []  # optimizer parameter groups
    for k, v in model.named_modules():
        if hasattr(v, 'bias') and isinstance(v.bias, nn.Parameter):
            pg2.append(v.bias)  # biases
        if isinstance(v, nn.BatchNorm2d):
            pg0.append(v.weight)  # no decay
        elif hasattr(v, 'weight') and isinstance(v.weight, nn.Parameter):
            pg1.append(v.weight)  # apply decay

    if opt.adam:
        optimizer = optim.Adam(pg0,
                               lr=hyp['lr0'],
                               betas=(hyp['momentum'],
                                      0.999))  # adjust beta1 to momentum
    else:
        optimizer = optim.SGD(pg0,
                              lr=hyp['lr0'],
                              momentum=hyp['momentum'],
                              nesterov=True)

    optimizer.add_param_group({
        'params': pg1,
        'weight_decay': hyp['weight_decay']
    })  # add pg1 with weight_decay
    optimizer.add_param_group({'params': pg2})  # add pg2 (biases)
    logger.info('Optimizer groups: %g .bias, %g conv.weight, %g other' %
                (len(pg2), len(pg1), len(pg0)))
    del pg0, pg1, pg2

    # Scheduler https://arxiv.org/pdf/1812.01187.pdf
    # https://pytorch.org/docs/stable/_modules/torch/optim/lr_scheduler.html#OneCycleLR
    lf = one_cycle(1, hyp['lrf'], epochs)  # cosine 1->hyp['lrf']
    scheduler = lr_scheduler.LambdaLR(optimizer, lr_lambda=lf)
    # plot_lr_scheduler(optimizer, scheduler, epochs)

    # Logging
    if rank in [-1, 0] and wandb and wandb.run is None:
        opt.hyp = hyp  # add hyperparameters
        wandb_run = wandb.init(
            config=opt,
            resume="allow",
            project='YOLOv5'
            if opt.project == 'runs/train' else Path(opt.project).stem,
            name=save_dir.stem,
            id=ckpt.get('wandb_id') if 'ckpt' in locals() else None)
    loggers = {'wandb': wandb}  # loggers dict

    # Resume
    start_epoch, best_fitness = 0, 0.0
    if pretrained:
        # Optimizer
        if ckpt['optimizer'] is not None:
            optimizer.load_state_dict(ckpt['optimizer'])
            best_fitness = ckpt['best_fitness']

        # Results
        if ckpt.get('training_results') is not None:
            with open(results_file, 'w') as file:
                file.write(ckpt['training_results'])  # write results.txt

        # Epochs
        start_epoch = ckpt['epoch'] + 1
        if opt.resume:
            assert start_epoch > 0, '%s training to %g epochs is finished, nothing to resume.' % (
                weights, epochs)
        if epochs < start_epoch:
            logger.info(
                '%s has been trained for %g epochs. Fine-tuning for %g additional epochs.'
                % (weights, ckpt['epoch'], epochs))
            epochs += ckpt['epoch']  # finetune additional epochs

        del ckpt, state_dict

    # Image sizes
    gs = int(model.stride.max())  # grid size (max stride)
    nl = model.model[
        -1].nl  # number of detection layers (used for scaling hyp['obj'])
    imgsz, imgsz_test = [check_img_size(x, gs) for x in opt.img_size
                         ]  # verify imgsz are gs-multiples

    # TODO 将cfg添加到配置变量中
    cfg_model = Darknet('cfg/yolov5s_v4.cfg',
                        (opt.img_size[0], opt.img_size[0])).to(device)
    # cfg_model = Darknet('cfg/yolov5s_v3.cfg', (416, 416)).to(device)
    copy_weight_v4(model, cfg_model)
    # 剪枝操作  sr开启稀疏训练  prune 不同的剪枝策略
    # 剪枝操作
    if opt.prune == 1:
        CBL_idx, _, prune_idx, shortcut_idx, _ = parse_module_defs2(
            cfg_model.module_defs)
        if opt.sr:
            print('shortcut sparse training')
    elif opt.prune == 0:
        CBL_idx, _, prune_idx = parse_module_defs(cfg_model.module_defs)
        if opt.sr:
            print('normal sparse training ')

    # DP mode
    if cuda and rank == -1 and torch.cuda.device_count() > 1:
        model = torch.nn.DataParallel(model)

    # SyncBatchNorm
    if opt.sync_bn and cuda and rank != -1:
        model = torch.nn.SyncBatchNorm.convert_sync_batchnorm(model).to(device)
        logger.info('Using SyncBatchNorm()')

    # EMA
    ema = ModelEMA(model) if rank in [-1, 0] else None

    # DDP mode
    if cuda and rank != -1:
        model = DDP(model,
                    device_ids=[opt.local_rank],
                    output_device=opt.local_rank)

    # Trainloader
    dataloader, dataset = create_dataloader(train_path,
                                            imgsz,
                                            batch_size,
                                            gs,
                                            opt,
                                            hyp=hyp,
                                            augment=True,
                                            cache=opt.cache_images,
                                            rect=opt.rect,
                                            rank=rank,
                                            world_size=opt.world_size,
                                            workers=opt.workers,
                                            image_weights=opt.image_weights,
                                            quad=opt.quad)
    mlc = np.concatenate(dataset.labels, 0)[:, 0].max()  # max label class
    nb = len(dataloader)  # number of batches
    assert mlc < nc, 'Label class %g exceeds nc=%g in %s. Possible class labels are 0-%g' % (
        mlc, nc, opt.data, nc - 1)

    # Process 0
    if rank in [-1, 0]:
        ema.updates = start_epoch * nb // accumulate  # set EMA updates
        testloader = create_dataloader(
            test_path,
            imgsz_test,
            total_batch_size,
            gs,
            opt,  # testloader
            hyp=hyp,
            cache=opt.cache_images and not opt.notest,
            rect=True,
            rank=-1,
            world_size=opt.world_size,
            workers=opt.workers,
            pad=0.5)[0]

        if not opt.resume:
            labels = np.concatenate(dataset.labels, 0)
            c = torch.tensor(labels[:, 0])  # classes
            # cf = torch.bincount(c.long(), minlength=nc) + 1.  # frequency
            # model._initialize_biases(cf.to(device))
            if plots:
                plot_labels(labels, save_dir, loggers)
                if tb_writer:
                    tb_writer.add_histogram('classes', c, 0)

            # Anchors
            if not opt.noautoanchor:
                check_anchors(dataset,
                              model=model,
                              thr=hyp['anchor_t'],
                              imgsz=imgsz)

    # Model parameters
    hyp['cls'] *= nc / 80.  # scale hyp['cls'] to class count
    hyp['obj'] *= imgsz**2 / 640.**2 * 3. / nl  # scale hyp['obj'] to image size and output layers
    model.nc = nc  # attach number of classes to model
    model.hyp = hyp  # attach hyperparameters to model
    model.gr = 1.0  # iou loss ratio (obj_loss = 1.0 or iou)
    model.class_weights = labels_to_class_weights(
        dataset.labels, nc).to(device) * nc  # attach class weights
    model.names = names

    for idx in prune_idx:
        bn_weights = gather_bn_weights(cfg_model.module_list, [idx])
        tb_writer.add_histogram('before_train_perlayer_bn_weights/hist',
                                bn_weights.numpy(),
                                idx,
                                bins='doane')

    # Start training
    t0 = time.time()
    nw = max(round(hyp['warmup_epochs'] * nb),
             1000)  # number of warmup iterations, max(3 epochs, 1k iterations)
    # nw = min(nw, (epochs - start_epoch) / 2 * nb)  # limit warmup to < 1/2 of training
    maps = np.zeros(nc)  # mAP per class
    results = (0, 0, 0, 0, 0, 0, 0
               )  # P, R, [email protected], [email protected], val_loss(box, obj, cls)
    scheduler.last_epoch = start_epoch - 1  # do not move
    scaler = amp.GradScaler(enabled=cuda)
    logger.info('Image sizes %g train, %g test\n'
                'Using %g dataloader workers\nLogging results to %s\n'
                'Starting training for %g epochs...' %
                (imgsz, imgsz_test, dataloader.num_workers, save_dir, epochs))
    for epoch in range(
            start_epoch, epochs
    ):  # epoch ------------------------------------------------------------------
        model.train()

        # Update image weights (optional)
        if opt.image_weights:
            # Generate indices
            if rank in [-1, 0]:
                cw = model.class_weights.cpu().numpy() * (
                    1 - maps)**2 / nc  # class weights
                iw = labels_to_image_weights(dataset.labels,
                                             nc=nc,
                                             class_weights=cw)  # image weights
                dataset.indices = random.choices(
                    range(dataset.n), weights=iw,
                    k=dataset.n)  # rand weighted idx
            # Broadcast if DDP
            if rank != -1:
                indices = (torch.tensor(dataset.indices)
                           if rank == 0 else torch.zeros(dataset.n)).int()
                dist.broadcast(indices, 0)
                if rank != 0:
                    dataset.indices = indices.cpu().numpy()

        # Update mosaic border
        # b = int(random.uniform(0.25 * imgsz, 0.75 * imgsz + gs) // gs * gs)
        # dataset.mosaic_border = [b - imgsz, -b]  # height, width borders

        mloss = torch.zeros(4, device=device)  # mean losses
        if rank != -1:
            dataloader.sampler.set_epoch(epoch)
        pbar = enumerate(dataloader)
        logger.info(
            ('\n' + '%10s' * 8) % ('Epoch', 'gpu_mem', 'box', 'obj', 'cls',
                                   'total', 'targets', 'img_size'))
        if rank in [-1, 0]:
            pbar = tqdm(pbar, total=nb)  # progress bar
        optimizer.zero_grad()
        sr_flag = get_sr_flag(epoch, opt.sr)
        for i, (
                imgs, targets, paths, _
        ) in pbar:  # batch -------------------------------------------------------------
            ni = i + nb * epoch  # number integrated batches (since train start)
            imgs = imgs.to(device, non_blocking=True).float(
            ) / 255.0  # uint8 to float32, 0-255 to 0.0-1.0

            # Warmup
            if ni <= nw:
                xi = [0, nw]  # x interp
                # model.gr = np.interp(ni, xi, [0.0, 1.0])  # iou loss ratio (obj_loss = 1.0 or iou)
                accumulate = max(
                    1,
                    np.interp(ni, xi, [1, nbs / total_batch_size]).round())
                for j, x in enumerate(optimizer.param_groups):
                    # bias lr falls from 0.1 to lr0, all other lrs rise from 0.0 to lr0
                    x['lr'] = np.interp(ni, xi, [
                        hyp['warmup_bias_lr'] if j == 2 else 0.0,
                        x['initial_lr'] * lf(epoch)
                    ])
                    if 'momentum' in x:
                        x['momentum'] = np.interp(
                            ni, xi, [hyp['warmup_momentum'], hyp['momentum']])

            # Multi-scale
            if opt.multi_scale:
                sz = random.randrange(imgsz * 0.5,
                                      imgsz * 1.5 + gs) // gs * gs  # size
                sf = sz / max(imgs.shape[2:])  # scale factor
                if sf != 1:
                    ns = [math.ceil(x * sf / gs) * gs for x in imgs.shape[2:]
                          ]  # new shape (stretched to gs-multiple)
                    imgs = F.interpolate(imgs,
                                         size=ns,
                                         mode='bilinear',
                                         align_corners=False)

            # Forward
            # with amp.autocast(enabled=cuda):
            #     pred = model(imgs)  # forward
            #     loss, loss_items = compute_loss(pred, targets.to(device), model)  # loss scaled by batch_size
            #     if rank != -1:
            #         loss *= opt.world_size  # gradient averaged between devices in DDP mode
            #     if opt.quad:
            #         loss *= 4.

            # Forward
            pred = model(imgs)
            # Loss
            loss, loss_items = compute_loss(pred, targets.to(device),
                                            model)  # scaled by batch_size
            if rank != -1:
                loss *= opt.world_size  # gradient averaged between devices in DDP mode
            if not torch.isfinite(loss):
                print('WARNING: non-finite loss, ending training ', loss_items)
                return results
            # Backward
            # scaler.scale(loss).backward()
            loss.backward()

            idx2mask = None
            # if opt.sr and opt.prune==1 and epoch > opt.epochs * 0.5:
            #     idx2mask = get_mask2(model, prune_idx, 0.85)
            # copy_weight(model,cfg_model)
            BNOptimizer.updateBN(sr_flag, cfg_model.module_list, opt.s,
                                 prune_idx, epoch, idx2mask, opt)

            # Optimize
            if ni % accumulate == 0:
                # scaler.step(optimizer)  # optimizer.step
                # scaler.update()
                optimizer.step()
                optimizer.zero_grad()
                if ema:
                    ema.update(model)

            # Print
            if rank in [-1, 0]:
                mloss = (mloss * i + loss_items) / (i + 1
                                                    )  # update mean losses
                mem = '%.3gG' % (torch.cuda.memory_reserved() / 1E9
                                 if torch.cuda.is_available() else 0)  # (GB)
                s = ('%10s' * 2 +
                     '%10.4g' * 6) % ('%g/%g' % (epoch, epochs - 1), mem,
                                      *mloss, targets.shape[0], imgs.shape[-1])
                pbar.set_description(s)

                # Plot
                if plots and ni < 3:
                    f = save_dir / f'train_batch{ni}.jpg'  # filename
                    Thread(target=plot_images,
                           args=(imgs, targets, paths, f),
                           daemon=True).start()
                    # if tb_writer:
                    #     tb_writer.add_image(f, result, dataformats='HWC', global_step=epoch)
                    #     tb_writer.add_graph(model, imgs)  # add model to tensorboard
                elif plots and ni == 3 and wandb:
                    wandb.log({
                        "Mosaics": [
                            wandb.Image(str(x), caption=x.name)
                            for x in save_dir.glob('train*.jpg')
                        ]
                    })

            # end batch ------------------------------------------------------------------------------------------------
        # end epoch ----------------------------------------------------------------------------------------------------

        # Scheduler
        lr = [x['lr'] for x in optimizer.param_groups]  # for tensorboard
        scheduler.step()

        # DDP process 0 or single-GPU
        if rank in [-1, 0]:
            # mAP
            if ema:
                ema.update_attr(model,
                                include=[
                                    'yaml', 'nc', 'hyp', 'gr', 'names',
                                    'stride', 'class_weights'
                                ])
            final_epoch = epoch + 1 == epochs
            if not opt.notest or final_epoch:  # Calculate mAP
                results, maps, times = test.test(
                    opt.data,
                    batch_size=total_batch_size,
                    imgsz=imgsz_test,
                    model=ema.ema,
                    single_cls=opt.single_cls,
                    dataloader=testloader,
                    save_dir=save_dir,
                    plots=plots and final_epoch,
                    log_imgs=opt.log_imgs if wandb else 0)

            # Write
            with open(results_file, 'a') as f:
                f.write(
                    s + '%10.4g' * 7 % results +
                    '\n')  # P, R, [email protected], [email protected], val_loss(box, obj, cls)
            if len(opt.name) and opt.bucket:
                os.system('gsutil cp %s gs://%s/results/results%s.txt' %
                          (results_file, opt.bucket, opt.name))

            # Log
            tags = [
                'train/box_loss',
                'train/obj_loss',
                'train/cls_loss',  # train loss
                'metrics/precision',
                'metrics/recall',
                'metrics/mAP_0.5',
                'metrics/mAP_0.5:0.95',
                'val/box_loss',
                'val/obj_loss',
                'val/cls_loss',  # val loss
                'x/lr0',
                'x/lr1',
                'x/lr2'
            ]  # params
            for x, tag in zip(list(mloss[:-1]) + list(results) + lr, tags):
                if tb_writer:
                    tb_writer.add_scalar(tag, x, epoch)  # tensorboard

                if wandb:
                    wandb.log({tag: x})  # W&B
            #剪枝后bn层权重
            bn_weights = gather_bn_weights(cfg_model.module_list, prune_idx)
            tb_writer.add_histogram('bn_weights/hist',
                                    bn_weights.numpy(),
                                    epoch,
                                    bins='doane')

            # Update best mAP
            fi = fitness(np.array(results).reshape(
                1, -1))  # weighted combination of [P, R, [email protected], [email protected]]
            if fi > best_fitness:
                best_fitness = fi

            # Save model
            save = (not opt.nosave) or (final_epoch and not opt.evolve)
            if save:
                with open(results_file, 'r') as f:  # create checkpoint
                    ckpt = {
                        'epoch':
                        epoch,
                        'best_fitness':
                        best_fitness,
                        'training_results':
                        f.read(),
                        'model':
                        ema.ema,
                        'optimizer':
                        None if final_epoch else optimizer.state_dict(),
                        'wandb_id':
                        wandb_run.id if wandb else None
                    }

                # Save last, best and delete
                torch.save(ckpt, last)
                if best_fitness == fi:
                    torch.save(ckpt, best)
                del ckpt
        # end epoch ----------------------------------------------------------------------------------------------------
    # end training
    for idx in prune_idx:
        bn_weights = gather_bn_weights(cfg_model.module_list, [idx])
        tb_writer.add_histogram('after_train_perlayer_bn_weights/hist',
                                bn_weights.numpy(),
                                idx,
                                bins='doane')

    if rank in [-1, 0]:
        # Strip optimizers
        final = best if best.exists() else last  # final model
        for f in [last, best]:
            if f.exists():
                strip_optimizer(f)  # strip optimizers
        if opt.bucket:
            os.system(f'gsutil cp {final} gs://{opt.bucket}/weights')  # upload

        # Plots
        if plots:
            plot_results(save_dir=save_dir)  # save as results.png
            if wandb:
                files = [
                    'results.png', 'precision_recall_curve.png',
                    'confusion_matrix.png'
                ]
                wandb.log({
                    "Results": [
                        wandb.Image(str(save_dir / f), caption=f)
                        for f in files if (save_dir / f).exists()
                    ]
                })
                if opt.log_artifacts:
                    wandb.log_artifact(artifact_or_path=str(final),
                                       type='model',
                                       name=save_dir.stem)

        # Test best.pt
        logger.info('%g epochs completed in %.3f hours.\n' %
                    (epoch - start_epoch + 1, (time.time() - t0) / 3600))
        if opt.data.endswith('coco.yaml') and nc == 80:  # if COCO
            for conf, iou, save_json in ([0.25, 0.45,
                                          False], [0.001, 0.65,
                                                   True]):  # speed, mAP tests
                results, _, _ = test.test(opt.data,
                                          batch_size=total_batch_size,
                                          imgsz=imgsz_test,
                                          conf_thres=conf,
                                          iou_thres=iou,
                                          model=attempt_load(final,
                                                             device).half(),
                                          single_cls=opt.single_cls,
                                          dataloader=testloader,
                                          save_dir=save_dir,
                                          save_json=save_json,
                                          plots=False)

    else:
        dist.destroy_process_group()

    wandb.run.finish() if wandb and wandb.run else None
    torch.cuda.empty_cache()
    return results
def train(hyp, opt, device, tb_writer=None):
    print(f'Hyperparameters {hyp}')
    log_dir = tb_writer.log_dir if tb_writer else 'runs/evolve'  # run directory
    wdir = str(Path(log_dir) / 'weights') + os.sep  # weights directory
    os.makedirs(wdir, exist_ok=True)
    last = wdir + 'last.pt'
    best = wdir + 'best.pt'
    results_file = log_dir + os.sep + 'results.txt'
    epochs, batch_size, total_batch_size, weights, rank = \
        opt.epochs, opt.batch_size, opt.total_batch_size, opt.weights, opt.local_rank
    # TODO: Use DDP logging. Only the first process is allowed to log.

    # Save run settings
    with open(Path(log_dir) / 'hyp.yaml', 'w') as f:
        yaml.dump(hyp, f, sort_keys=False)
    with open(Path(log_dir) / 'opt.yaml', 'w') as f:
        yaml.dump(vars(opt), f, sort_keys=False)

    # Configure
    cuda = device.type != 'cpu'
    init_seeds(2 + rank)
    with open(opt.data) as f:
        data_dict = yaml.load(f, Loader=yaml.FullLoader)  # model dict
    train_path = data_dict['train']
    test_path = data_dict['val']
    nc, names = (1, ['item']) if opt.single_cls else (int(data_dict['nc']), data_dict['names'])  # number classes, names
    assert len(names) == nc, '%g names found for nc=%g dataset in %s' % (len(names), nc, opt.data)  # check

    # Remove previous results
    if rank in [-1, 0]:
        for f in glob.glob('*_batch*.jpg') + glob.glob(results_file):
            os.remove(f)

    # Create model
    model = Model(opt.cfg, nc=nc).to(device)
    #TODO 将cfg添加到配置变量中
    cfg_model = Darknet('cfg/yolov5s_v2_hand.cfg', (opt.img_size[0], opt.img_size[0])).to(device)

    # Image sizes
    gs = int(max(model.stride))  # grid size (max stride)
    imgsz, imgsz_test = [check_img_size(x, gs) for x in opt.img_size]  # verify imgsz are gs-multiples

    # Optimizer
    nbs = 64  # nominal batch size
    # default DDP implementation is slow for accumulation according to: https://pytorch.org/docs/stable/notes/ddp.html
    # all-reduce operation is carried out during loss.backward().
    # Thus, there would be redundant all-reduce communications in a accumulation procedure,
    # which means, the result is still right but the training speed gets slower.
    # TODO: If acceleration is needed, there is an implementation of allreduce_post_accumulation
    # in https://github.com/NVIDIA/DeepLearningExamples/blob/master/PyTorch/LanguageModeling/BERT/run_pretraining.py
    accumulate = max(round(nbs / total_batch_size), 1)  # accumulate loss before optimizing
    hyp['weight_decay'] *= total_batch_size * accumulate / nbs  # scale weight_decay

    pg0, pg1, pg2 = [], [], []  # optimizer parameter groups
    for k, v in model.named_parameters():
        if v.requires_grad:
            if '.bias' in k:
                pg2.append(v)  # biases
            elif '.weight' in k and '.bn' not in k:
                pg1.append(v)  # apply weight decay
            else:
                pg0.append(v)  # all else

    if opt.adam:
        optimizer = optim.Adam(pg0, lr=hyp['lr0'], betas=(hyp['momentum'], 0.999))  # adjust beta1 to momentum
    else:
        optimizer = optim.SGD(pg0, lr=hyp['lr0'], momentum=hyp['momentum'], nesterov=True)

    optimizer.add_param_group({'params': pg1, 'weight_decay': hyp['weight_decay']})  # add pg1 with weight_decay
    optimizer.add_param_group({'params': pg2})  # add pg2 (biases)
    print('Optimizer groups: %g .bias, %g conv.weight, %g other' % (len(pg2), len(pg1), len(pg0)))
    del pg0, pg1, pg2

    # Scheduler https://arxiv.org/pdf/1812.01187.pdf
    # https://pytorch.org/docs/stable/_modules/torch/optim/lr_scheduler.html#OneCycleLR
    lf = lambda x: (((1 + math.cos(x * math.pi / epochs)) / 2) ** 1.0) * 0.8 + 0.2  # cosine
    scheduler = lr_scheduler.LambdaLR(optimizer, lr_lambda=lf)
    # plot_lr_scheduler(optimizer, scheduler, epochs)

    # Load Model
    with torch_distributed_zero_first(rank):
        attempt_download(weights)
    start_epoch, best_fitness = 0, 0.0
    if weights.endswith('.pt'):  # pytorch format
        ckpt = torch.load(weights, map_location=device)  # load checkpoint

        # load model
        try:
            exclude = ['anchor']  # exclude keys
            ckpt['model'] = {k: v for k, v in ckpt['model'].float().state_dict().items()
                             if k in model.state_dict() and not any(x in k for x in exclude)
                             and model.state_dict()[k].shape == v.shape}
            model.load_state_dict(ckpt['model'], strict=False)
            print('Transferred %g/%g items from %s' % (len(ckpt['model']), len(model.state_dict()), weights))
        except KeyError as e:
            s = "%s is not compatible with %s. This may be due to model differences or %s may be out of date. " \
                "Please delete or update %s and try again, or use --weights '' to train from scratch." \
                % (weights, opt.cfg, weights, weights)
            raise KeyError(s) from e

        # load optimizer
        if ckpt['optimizer'] is not None:
            optimizer.load_state_dict(ckpt['optimizer'])
            best_fitness = ckpt['best_fitness']

        # load results
        if ckpt.get('training_results') is not None:
            with open(results_file, 'w') as file:
                file.write(ckpt['training_results'])  # write results.txt

        # epochs
        start_epoch = ckpt['epoch'] + 1
        if epochs < start_epoch:
            print('%s has been trained for %g epochs. Fine-tuning for %g additional epochs.' %
                  (weights, ckpt['epoch'], epochs))
            epochs += ckpt['epoch']  # finetune additional epochs

        del ckpt

    #复制模型权重 目前只支持yolov5s
    copy_weight(model,cfg_model)
    # 剪枝操作  sr开启稀疏训练  prune 不同的剪枝策略
    # 剪枝操作
    if opt.prune == 1:
        CBL_idx, _, prune_idx, shortcut_idx, _ = parse_module_defs2(cfg_model.module_defs)
        if opt.sr:
            print('shortcut sparse training')
    elif opt.prune == 0:
        CBL_idx, _, prune_idx = parse_module_defs(cfg_model.module_defs)
        if opt.sr:
            print('normal sparse training ')

    # DP mode
    if cuda and rank == -1 and torch.cuda.device_count() > 1:
        model = torch.nn.DataParallel(model)

    # SyncBatchNorm
    if opt.sync_bn and cuda and rank != -1:
        model = torch.nn.SyncBatchNorm.convert_sync_batchnorm(model).to(device)
        print('Using SyncBatchNorm()')

    # Exponential moving average
    ema = ModelEMA(model) if rank in [-1, 0] else None

    # DDP mode
    if cuda and rank != -1:
        model = DDP(model, device_ids=[rank], output_device=rank)

    # Trainloader
    dataloader, dataset = create_dataloader(train_path, imgsz, batch_size, gs, opt, hyp=hyp, augment=True,
                                            cache=opt.cache_images, rect=opt.rect, local_rank=rank,
                                            world_size=opt.world_size)
    mlc = np.concatenate(dataset.labels, 0)[:, 0].max()  # max label class
    nb = len(dataloader)  # number of batches
    assert mlc < nc, 'Label class %g exceeds nc=%g in %s. Possible class labels are 0-%g' % (mlc, nc, opt.data, nc - 1)

    # Testloader
    if rank in [-1, 0]:
        # local_rank is set to -1. Because only the first process is expected to do evaluation.
        testloader = create_dataloader(test_path, imgsz_test, total_batch_size, gs, opt, hyp=hyp, augment=False,
                                       cache=opt.cache_images, rect=True, local_rank=-1, world_size=opt.world_size)[0]

    # Model parameters
    hyp['cls'] *= nc / 80.  # scale coco-tuned hyp['cls'] to current dataset
    model.nc = nc  # attach number of classes to model
    model.hyp = hyp  # attach hyperparameters to model
    model.gr = 1.0  # giou loss ratio (obj_loss = 1.0 or giou)
    model.class_weights = labels_to_class_weights(dataset.labels, nc).to(device)  # attach class weights
    model.names = names

    # Class frequency
    if rank in [-1, 0]:
        labels = np.concatenate(dataset.labels, 0)
        c = torch.tensor(labels[:, 0])  # classes
        # cf = torch.bincount(c.long(), minlength=nc) + 1.
        # model._initialize_biases(cf.to(device))
        plot_labels(labels, save_dir=log_dir)
        if tb_writer:
            # tb_writer.add_hparams(hyp, {})  # causes duplicate https://github.com/ultralytics/yolov5/pull/384
            tb_writer.add_histogram('classes', c, 0)

        # Check anchors
        if not opt.noautoanchor:
            check_anchors(dataset, model=model, thr=hyp['anchor_t'], imgsz=imgsz)

    #剪枝前bn层权重
    for idx in prune_idx:
        bn_weights = gather_bn_weights(cfg_model.module_list, [idx])
        tb_writer.add_histogram('before_train_perlayer_bn_weights/hist', bn_weights.numpy(), idx, bins='doane')

    # Start training
    t0 = time.time()
    nw = max(3 * nb, 1e3)  # number of warmup iterations, max(3 epochs, 1k iterations)
    # nw = min(nw, (epochs - start_epoch) / 2 * nb)  # limit warmup to < 1/2 of training
    maps = np.zeros(nc)  # mAP per class
    results = (0, 0, 0, 0, 0, 0, 0)  # 'P', 'R', 'mAP', 'F1', 'val GIoU', 'val Objectness', 'val Classification'
    scheduler.last_epoch = start_epoch - 1  # do not move
    # scaler = amp.GradScaler(enabled=cuda)
    if rank in [0, -1]:
        print('Image sizes %g train, %g test' % (imgsz, imgsz_test))
        print('Using %g dataloader workers' % dataloader.num_workers)
        print('Starting training for %g epochs...' % epochs)
    # torch.autograd.set_detect_anomaly(True)
    for epoch in range(start_epoch, epochs):  # epoch ------------------------------------------------------------------
        model.train()

        # Update image weights (optional)
        if dataset.image_weights:
            # Generate indices
            if rank in [-1, 0]:
                w = model.class_weights.cpu().numpy() * (1 - maps) ** 2  # class weights
                image_weights = labels_to_image_weights(dataset.labels, nc=nc, class_weights=w)
                dataset.indices = random.choices(range(dataset.n), weights=image_weights,
                                                 k=dataset.n)  # rand weighted idx
            # Broadcast if DDP
            if rank != -1:
                indices = torch.zeros([dataset.n], dtype=torch.int)
                if rank == 0:
                    indices[:] = torch.from_tensor(dataset.indices, dtype=torch.int)
                dist.broadcast(indices, 0)
                if rank != 0:
                    dataset.indices = indices.cpu().numpy()

        # Update mosaic border
        # b = int(random.uniform(0.25 * imgsz, 0.75 * imgsz + gs) // gs * gs)
        # dataset.mosaic_border = [b - imgsz, -b]  # height, width borders

        mloss = torch.zeros(4, device=device)  # mean losses
        if rank != -1:
            dataloader.sampler.set_epoch(epoch)
        pbar = enumerate(dataloader)
        if rank in [-1, 0]:
            print(('\n' + '%10s' * 8) % ('Epoch', 'gpu_mem', 'GIoU', 'obj', 'cls', 'total', 'targets', 'img_size'))
            pbar = tqdm(pbar, total=nb)  # progress bar
        optimizer.zero_grad()
        sr_flag = get_sr_flag(epoch, opt.sr)
        for i, (imgs, targets, paths, _) in pbar:  # batch -------------------------------------------------------------
            ni = i + nb * epoch  # number integrated batches (since train start)
            imgs = imgs.to(device, non_blocking=True).float() / 255.0  # uint8 to float32, 0-255 to 0.0-1.0
            # Warmup
            if ni <= nw:
                xi = [0, nw]  # x interp
                # model.gr = np.interp(ni, xi, [0.0, 1.0])  # giou loss ratio (obj_loss = 1.0 or giou)
                accumulate = max(1, np.interp(ni, xi, [1, nbs / total_batch_size]).round())
                for j, x in enumerate(optimizer.param_groups):
                    # bias lr falls from 0.1 to lr0, all other lrs rise from 0.0 to lr0
                    x['lr'] = np.interp(ni, xi, [0.1 if j == 2 else 0.0, x['initial_lr'] * lf(epoch)])
                    if 'momentum' in x:
                        x['momentum'] = np.interp(ni, xi, [0.9, hyp['momentum']])

            # Multi-scale
            if opt.multi_scale:
                sz = random.randrange(imgsz * 0.5, imgsz * 1.5 + gs) // gs * gs  # size
                sf = sz / max(imgs.shape[2:])  # scale factor
                if sf != 1:
                    ns = [math.ceil(x * sf / gs) * gs for x in imgs.shape[2:]]  # new shape (stretched to gs-multiple)
                    imgs = F.interpolate(imgs, size=ns, mode='bilinear', align_corners=False)

            # Forward
            pred = model(imgs)

            # Loss
            loss, loss_items = compute_loss(pred, targets.to(device), model)  # scaled by batch_size
            if rank != -1:
                loss *= opt.world_size  # gradient averaged between devices in DDP mode
            if not torch.isfinite(loss):
                print('WARNING: non-finite loss, ending training ', loss_items)
                return results

            # Backward
            loss.backward()

            # Autocast
            # with amp.autocast(enabled=cuda):
            #     # Forward
            #     pred = model(imgs)

            #     # Loss
            #     loss, loss_items = compute_loss(pred, targets.to(device), model)  # scaled by batch_size
            #     if rank != -1:
            #         loss *= opt.world_size  # gradient averaged between devices in DDP mode
            #     # if not torch.isfinite(loss):
            #     #     print('WARNING: non-finite loss, ending training ', loss_items)
            #     #     return results

            # # Backward
            # scaler.scale(loss).backward()

            idx2mask = None
            # if opt.sr and opt.prune==1 and epoch > opt.epochs * 0.5:
            #     idx2mask = get_mask2(model, prune_idx, 0.85)
            # copy_weight(model,cfg_model)
            BNOptimizer.updateBN(sr_flag, cfg_model.module_list, opt.s, prune_idx, epoch, idx2mask, opt)

            # Optimize
            if ni % accumulate == 0:
                # scaler.step(optimizer)  # optimizer.step
                # scaler.update()
                optimizer.step()
                optimizer.zero_grad()
                if ema is not None:
                    ema.update(model)

            # Print
            if rank in [-1, 0]:
                mloss = (mloss * i + loss_items) / (i + 1)  # update mean losses
                mem = '%.3gG' % (torch.cuda.memory_reserved() / 1E9 if torch.cuda.is_available() else 0)  # (GB)
                s = ('%10s' * 2 + '%10.4g' * 6) % (
                    '%g/%g' % (epoch, epochs - 1), mem, *mloss, targets.shape[0], imgs.shape[-1])
                pbar.set_description(s)

                # Plot
                if ni < 3:
                    f = str(Path(log_dir) / ('train_batch%g.jpg' % ni))  # filename
                    result = plot_images(images=imgs, targets=targets, paths=paths, fname=f)
                    if tb_writer and result is not None:
                        tb_writer.add_image(f, result, dataformats='HWC', global_step=epoch)
                        # tb_writer.add_graph(model, imgs)  # add model to tensorboard

            # end batch ------------------------------------------------------------------------------------------------

        # Scheduler
        scheduler.step()

        # DDP process 0 or single-GPU
        if rank in [-1, 0]:
            # mAP
            if ema is not None:
                ema.update_attr(model, include=['yaml', 'nc', 'hyp', 'gr', 'names', 'stride'])
            final_epoch = epoch + 1 == epochs
            if not opt.notest or final_epoch:  # Calculate mAP
                results, maps, times = test.test(opt.data,
                                                 batch_size=total_batch_size,
                                                 imgsz=imgsz_test,
                                                 save_json=final_epoch and opt.data.endswith(os.sep + 'coco.yaml'),
                                                 model=ema.ema.module if hasattr(ema.ema, 'module') else ema.ema,
                                                 single_cls=opt.single_cls,
                                                 dataloader=testloader,
                                                 save_dir=log_dir)

            # Write
            with open(results_file, 'a') as f:
                f.write(s + '%10.4g' * 7 % results + '\n')  # P, R, mAP, F1, test_losses=(GIoU, obj, cls)
            if len(opt.name) and opt.bucket:
                os.system('gsutil cp %s gs://%s/results/results%s.txt' % (results_file, opt.bucket, opt.name))

            # Tensorboard
            if tb_writer:
                tags = ['train/giou_loss', 'train/obj_loss', 'train/cls_loss',
                        'metrics/precision', 'metrics/recall', 'metrics/mAP_0.5', 'metrics/mAP_0.5:0.95',
                        'val/giou_loss', 'val/obj_loss', 'val/cls_loss']
                for x, tag in zip(list(mloss[:-1]) + list(results), tags):
                    tb_writer.add_scalar(tag, x, epoch)
                #剪枝后bn层权重
                bn_weights = gather_bn_weights(cfg_model.module_list, prune_idx)
                tb_writer.add_histogram('bn_weights/hist', bn_weights.numpy(), epoch, bins='doane')

            # Update best mAP
            fi = fitness(np.array(results).reshape(1, -1))  # fitness_i = weighted combination of [P, R, mAP, F1]
            if fi > best_fitness:
                best_fitness = fi

            # Save model
            save = (not opt.nosave) or (final_epoch and not opt.evolve)
            if save:
                with open(results_file, 'r') as f:  # create checkpoint
                    ckpt = {'epoch': epoch,
                            'best_fitness': best_fitness,
                            'training_results': f.read(),
                            'model': ema.ema.module if hasattr(ema, 'module') else ema.ema,
                            'optimizer': None if final_epoch else optimizer.state_dict()}

                # Save last, best and delete
                torch.save(ckpt, last)
                if best_fitness == fi:
                    torch.save(ckpt, best)
                del ckpt
        # end epoch ----------------------------------------------------------------------------------------------------
    # end training

    if rank in [-1, 0]:
        # Strip optimizers
        n = ('_' if len(opt.name) and not opt.name.isnumeric() else '') + opt.name
        fresults, flast, fbest = 'results%s.txt' % n, wdir + 'last%s.pt' % n, wdir + 'best%s.pt' % n
        for f1, f2 in zip([wdir + 'last.pt', wdir + 'best.pt', 'results.txt'], [flast, fbest, fresults]):
            if os.path.exists(f1):
                os.rename(f1, f2)  # rename
                ispt = f2.endswith('.pt')  # is *.pt
                strip_optimizer(f2) if ispt else None  # strip optimizer
                os.system('gsutil cp %s gs://%s/weights' % (f2, opt.bucket)) if opt.bucket and ispt else None  # upload
        # Finish
        if not opt.evolve:
            plot_results(save_dir=log_dir)  # save as results.png
        print('%g epochs completed in %.3f hours.\n' % (epoch - start_epoch + 1, (time.time() - t0) / 3600))

    dist.destroy_process_group() if rank not in [-1, 0] else None
    torch.cuda.empty_cache()
    return results