PyTorch——(3) tensor基本运算

矩阵乘法

只对2d矩阵有效，因为矩阵乘法是定义在2d矩阵上的

torch.mm(a,b)
torch.matmul(a,b)
a@b

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对tensor中的每一个元素都进行幂运算
![在这里插入图片描述]( https://img-blog.csdnimg.cn/20210425200604365.png?x-oss-process=image/watermark ,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM0MjEzMjYw,size_16,color_FFFFFF,t_70)

![在这里插入图片描述]( https://img-blog.csdnimg.cn/20210425200742825.png?x-oss-process=image/watermark ,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM0MjEzMjYw,size_16,color_FFFFFF,t_70)

![在这里插入图片描述]( https://img-blog.csdnimg.cn/20210425200852826.png?x-oss-process=image/watermark ,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM0MjEzMjYw,size_16,color_FFFFFF,t_70)

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将小于10的都等于10
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将大于10的都等于10
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参数为几范数
![在这里插入图片描述]( https://img-blog.csdnimg.cn/20210425201402403.png?x-oss-process=image/watermark ,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM0MjEzMjYw,size_16,color_FFFFFF,t_70)
![在这里插入图片描述]( https://img-blog.csdnimg.cn/20210425201445567.png?x-oss-process=image/watermark ,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM0MjEzMjYw,size_16,color_FFFFFF,t_70)

![在这里插入图片描述]( https://img-blog.csdnimg.cn/20210425201750534.png?x-oss-process=image/watermark ,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM0MjEzMjYw,size_16,color_FFFFFF,t_70)- 指定维度
![在这里插入图片描述]( https://img-blog.csdnimg.cn/20210425201821436.png?x-oss-process=image/watermark ,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM0MjEzMjYw,size_16,color_FFFFFF,t_70)
将结果的维度和输入的数据维度一致

keepdim = True

![在这里插入图片描述]( https://img-blog.csdnimg.cn/20210425202257651.png?x-oss-process=image/watermark ,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM0MjEzMjYw,size_16,color_FFFFFF,t_70)

max()相当于topk(1)

largest=True 表示最大的k个 
largest = False 表示最小的k个

![在这里插入图片描述]( https://img-blog.csdnimg.cn/20210425202425286.png?x-oss-process=image/watermark ,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM0MjEzMjYw,size_16,color_FFFFFF,t_70)

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![在这里插入图片描述]( https://img-blog.csdnimg.cn/20210425202922490.png?x-oss-process=image/watermark ,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM0MjEzMjYw,size_16,color_FFFFFF,t_70)![在这里插入图片描述]( https://img-blog.csdnimg.cn/20210425202939967.png?x-oss-process=image/watermark ,type_ZmFuZ3poZW5naGVpdGk,shadow_10,text_aHR0cHM6Ly9ibG9nLmNzZG4ubmV0L3FxXzM0MjEzMjYw,size_16,color_FFFFFF,t_70)