following is the definition of torch.addmm 's parameters:
torch. addmm ( beta=1 ,  mat ,  alpha=1 ,  mat1 ,  mat2 ,  out=None ) → Tensor
from https://pytorch.org/docs/stable/torch.html?highlight=addmm#torch.addmm 239
but under it there is an example:



M = torch.randn(2, 3)
mat1 = torch.randn(2, 3)
mat2 = torch.randn(3, 3)
torch.addmm(M, mat1, mat2)
tensor([[-4.8716, 1.4671, -1.3746],
[ 0.7573, -3.9555, -2.8681]])
the call of torch.addmm in the example only uses 3 parameters, when addmm’s last 2 parameters don’t heve a default value.
This is all my confusion about it.