如何將1*1的tensor類型的變量轉換爲Python的標量?
如下面這行代碼所示:
def ssim(img1,img2):
img1 = torch.from_numpy(np.rollaxis(img1, 2)).float().unsqueeze(0)/255.0
img2 = torch.from_numpy(np.rollaxis(img2, 2)).float().unsqueeze(0)/255.0
img1 = Variable( img1, requires_grad=False) # torch.Size([256, 256, 3])
img2 = Variable( img2, requires_grad = False)
ssim_value = pytorch_ssim.ssim(img1, img2).item()
return ssim_value
在倒數第2行中,我們想將計算得到的pytorch_ssim.ssim(img1, img2)(FloatTensor類型,1*1)轉換爲Python的Float類型標量。本來上面代碼中使用.item()的方法是可以的,但今天竟然報錯了:
*** AttributeError: 'Variable' object has no attribute 'item'
報錯原因還不清楚,猜測可能是版本的問題?
經過多次嘗試,將倒數第二行改爲下面的代碼即可:
ssim_value = float(pytorch_ssim.ssim(img1, img2))