TypeError: can't convert CUDA tensor to numpy.

[CyKaMing]

I am running with RTX2080ti python 3.6 , pytorch 1.0.1
But this error has shown up.

STEP 1000 x 15
Source to target (backtranslation)
Traceback (most recent call last):
File "train.py", line 20, in
undreamt.train.main_train()
File "/home/{mypath}/undreamt-master/undreamt/train.py", line 307, in main_train
logger.log(step)
File "/home/{mypath}/Translation/undreamt-master/undreamt/train.py", line 415, in log
.format(self.trainer.perplexity_per_word(), self.trainer.total_time(),
File "/home/{mypath}/Translation/undreamt-master/undreamt/train.py", line 357, in perplexity_per_word
return np.exp(self.loss/self.trg_word_count)
File "/home/{mypath}/anaconda3/envs/Translation/lib/python3.6/site-packages/torch/tensor.py", line 450, in array
return self.numpy()
TypeError: can't convert CUDA tensor to numpy. Use Tensor.cpu() to copy the tensor to host memory first.

Have any solutions, please?