我正在尝试使用多 GPU 的 yolov3...

    def evaluate(self):
        self.models.eval()

        labels = []
        sample_metrics = []  # List of tuples (TP,confs,pred)
        for batch_i,(_,imgs,targets) in enumerate(tqdm.tqdm(self.valid_dataloader,desc="Detecting objects")):
            # Extract labels
            labels += targets[:,1].tolist()
            # Rescale target
            targets[:,2:] = xywh2xyxy(targets[:,2:])
            targets[:,2:] *= self.img_size

            #targets = targets.cuda()

            #imgs = Variable(imgs.type(Tensor),requires_grad=False)

            imgs = imgs.cuda()

            with torch.no_grad():
                outputs = self.models(imgs)
                outputs = non_max_suppression(outputs,conf_thres=self.conf_thres,nms_thres=self.nms_thres)

            sample_metrics += get_batch_statistics(outputs,targets,iou_threshold=self.iou_thres)

        # concatenate sample statistics
        true_positives,pred_scores,pred_labels = [np.concatenate(x,0) for x in list(zip(*sample_metrics))]
        precision,recall,AP,f1,ap_class = ap_per_class(true_positives,pred_labels,labels)

        return precision,ap_class

如果我使用那两条注释行，我将面临

TypeError: can’t convert CUDA tensor to numpy. Use Tensor.cpu() to copy the tensor to host memory first

但如果我不这样做，我会面对

RuntimeError: Expected all tensors to be on the same device,but found at least two devices,cuda:0 and cpu!

如何解决？

跟踪：

    Traceback (most recent call last):
    File "D:/Code/DeblurGANv2-master/train.py",line 415,in <module>
        trainer.train()
    File "D:/Code/DeblurGANv2-master/train.py",line 253,in train
        self._run_epoch(epoch)
    File "D:/Code/DeblurGANv2-master/train.py",line 287,in _run_epoch
        loss_detect = self.calculate()
    File "D:/Code/DeblurGANv2-master/train.py",line 224,in calculate
        precision,ap_class = self.evaluate()
    File "D:/Code/DeblurGANv2-master/train.py",line 160,in evaluate
        sample_metrics += get_batch_statistics(outputs,iou_threshold=self.iou_thres)
    File "D:\Code\DeblurGANv2-master\util\utils.py",line 172,in 
    get_batch_statistics
        if pred_label not in target_labels:
    File "D:\soft\Anaconda3\envs\DeblurGANv2-master\lib\site- 
    packages\torch\tensor.py",line 659,in __contains__
        return (element == self).any().item()  # type: ignore[union-attr]
    File "D:\soft\Anaconda3\envs\DeblurGANv2-master\lib\site- 
   packages\torch\tensor.py",line 27,in wrapped
        return f(*args,**kwargs)
    RuntimeError: Expected all tensors to be on the same device,but found 
    at least two devices,cuda:0 and cpu!

我假设问题出在sample_metrics上，无论是把这个张量放在GPU还是CPU上，总是有问题......