einsum 简介 | Python技术交流与分享

文章目录

import torch
a = torch.arange(6).reshape(2, 3)
#对a进行转置
torch.einsum('ij->ji', [a])

import torch

a = torch.arange(6).reshape(2, 3)

#对a进行转置

torch.einsum('ij->ji', [a])

$b=\sum_i\sum_j A_{ij}$

a = torch.arange(6).reshape(2, 3)
#对矩阵a进行求和
torch.einsum('ij->', [a])

a = torch.arange(6).reshape(2, 3)

#对矩阵a进行求和

torch.einsum('ij->', [a])

$b_j=\sum_i A_{ij}$

#对矩阵按列求和，即对下标j进行求和
torch.einsum('ij->j', [a])

1 2	#对矩阵按列求和，即对下标j进行求和 torch.einsum('ij->j', [a])

a = torch.arange(6).reshape(2, 3)
b = torch.arange(3)
#a与b的内积，a乘以b的转置
torch.einsum('ik,k->i', [a, b])

a = torch.arange(6).reshape(2, 3)

b = torch.arange(3)

#a与b的内积，a乘以b的转置

torch.einsum('ik,k->i', [a, b])

a = torch.arange(6).reshape(2, 3)
b = torch.arange(15).reshape(3, 5)
torch.einsum('ik,kj->ij', [a, b])

a = torch.arange(6).reshape(2, 3)

b = torch.arange(15).reshape(3, 5)

torch.einsum('ik,kj->ij', [a, b])

同阶矩阵相乘

a = torch.arange(6).reshape(2, 3)
b = torch.arange(6,12).reshape(2, 3)
torch.einsum('ij,ij->ij', [a, b])

a = torch.arange(6).reshape(2, 3)

b = torch.arange(6,12).reshape(2, 3)

torch.einsum('ij,ij->ij', [a, b])

a = torch.randn(3,2,5)
b = torch.randn(3,5,3)
torch.einsum('ijk,ikl->ijl', [a, b])

a = torch.randn(3,2,5)

b = torch.randn(3,5,3)

torch.einsum('ijk,ikl->ijl', [a, b])

测试表格