Python 如何从pytorch中给定位置的每行中获取值?
如何根据包含每行位置的一维数组从二维火炬数组中获取值: 例如:Python 如何从pytorch中给定位置的每行中获取值?,python,pytorch,Python,Pytorch,如何根据包含每行位置的一维数组从二维火炬数组中获取值: 例如: a = torch.randn((5,5)) >>> a tensor([[ 0.0740, -0.3129, 0.7814, -0.0519, 1.3503], [ 1.1985, 0.2098, -0.0326, 0.3922, 0.5037], [-1.4334, 1.4047, -0.6607, -1.8024, -0.0088], [ 1.211
a = torch.randn((5,5))
>>> a
tensor([[ 0.0740, -0.3129, 0.7814, -0.0519, 1.3503],
[ 1.1985, 0.2098, -0.0326, 0.3922, 0.5037],
[-1.4334, 1.4047, -0.6607, -1.8024, -0.0088],
[ 1.2116, 0.5928, 1.4041, 1.0494, -0.1146],
[ 0.4173, 1.0482, 0.5244, -2.1767, 0.5264]])
b = torch.randint(0,5, (5,))
>>> b
tensor([1, 0, 1, 3, 2])
desired output:
tensor([-0.3129,
1.1985,
1.4047,
1.0494,
0.5244])
我想在张量b
例如:
a = torch.randn((5,5))
>>> a
tensor([[ 0.0740, -0.3129, 0.7814, -0.0519, 1.3503],
[ 1.1985, 0.2098, -0.0326, 0.3922, 0.5037],
[-1.4334, 1.4047, -0.6607, -1.8024, -0.0088],
[ 1.2116, 0.5928, 1.4041, 1.0494, -0.1146],
[ 0.4173, 1.0482, 0.5244, -2.1767, 0.5264]])
b = torch.randint(0,5, (5,))
>>> b
tensor([1, 0, 1, 3, 2])
desired output:
tensor([-0.3129,
1.1985,
1.4047,
1.0494,
0.5244])
这里,通过张量b
选择给定位置的每个元素
我试过:
for index in range(b.size(-1)):
val = torch.cat((val,a[index,b[index]].view(1,-1)), dim=0) if val is not None else a[index,b[index]].view(1,-1)
>>> val
tensor([[-0.3129],
[ 1.1985],
[ 1.4047],
[ 1.0494],
[ 0.5244]])
然而,有张量索引的方法吗?
我尝试了两种使用张量索引的解决方案,但没有一种有效。您可以使用
a.聚集(1,b.取消聚集(1))
张量([-0.3129],
[ 1.1985],
[ 1.4047],
[ 1.0494],
[ 0.5244]])
或
>a[范围(len(a)),b].取消查询(1)
张量([-0.3129],
[ 1.1985],
[ 1.4047],
[ 1.0494],
[ 0.5244]])