1.
np.array才可以broadcasting
![](https://img.haomeiwen.com/i5040713/5154776bf29ecb54.png)
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2.
![](https://img.haomeiwen.com/i5040713/3d94e59b63a65145.png)
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![](https://img.haomeiwen.com/i5040713/de037fdde6aa7f4d.png)
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![](https://img.haomeiwen.com/i5040713/dca5d5f08ca7a1e7.png)
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3.
乘* 号表示在每个维度上,都是元素对应相乘,得到新的向量。
![](https://img.haomeiwen.com/i5040713/72b6cfa702064307.png)
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![](https://img.haomeiwen.com/i5040713/e18573f452cd3164.png)
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![](https://img.haomeiwen.com/i5040713/27ddc40bb6e1dee9.png)
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4.
-1出现在reshape中
![](https://img.haomeiwen.com/i5040713/ee10a7e490ae8d98.png)
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5.
![](https://img.haomeiwen.com/i5040713/1edc4996f4dbc895.png)
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![](https://img.haomeiwen.com/i5040713/6917975018456397.png)
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6.
![](https://img.haomeiwen.com/i5040713/9f08411d9682fb0b.png)
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7.
![](https://img.haomeiwen.com/i5040713/b7fe129628be3220.png)
Screen Shot 2017-10-14 at 12.44.00 PM.png