From b048c4dd84653dc703038481fa5fd92a1fbea37c Mon Sep 17 00:00:00 2001
From: Dolly Ye <1375373964@qq.com>
Date: Sat, 17 Feb 2018 22:09:20 -0800
Subject: [PATCH] torch.dot does not broadcast

torch.dot() can only work for 1 dimension tensor.

http://pytorch.org/docs/master/torch.html
https://github.com/pytorch/pytorch/issues/2313
---
 tutorial-contents-notebooks/201_torch_numpy.ipynb | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/tutorial-contents-notebooks/201_torch_numpy.ipynb b/tutorial-contents-notebooks/201_torch_numpy.ipynb
index d2cec63..ecf445a 100644
--- a/tutorial-contents-notebooks/201_torch_numpy.ipynb
+++ b/tutorial-contents-notebooks/201_torch_numpy.ipynb
@@ -279,10 +279,11 @@
    "source": [
     "# incorrect method\n",
     "data = np.array(data)\n",
+    "tensor = torch.Tensor([1,2,3,4]\n",
     "print(\n",
     "    '\\nmatrix multiplication (dot)',\n",
     "    '\\nnumpy: ', data.dot(data),        # [[7, 10], [15, 22]]\n",
-    "    '\\ntorch: ', tensor.dot(tensor)     # this will convert tensor to [1,2,3,4], you'll get 30.0\n",
+    "    '\\ntorch: ', torch.dot(tensor.dot(tensor)     # 30.0. Beware that torch.dot does not broadcast, only works for 1-dimensional tensor\n",
     ")"
    ]
   },
@@ -360,7 +361,8 @@
     }
    ],
    "source": [
-    "tensor.dot(tensor)"
+    "torch.dot(torch.Tensor([2, 3]), torch.Tensor([2, 1]))
+7.0"
    ]
   },
   {