关于alignment和uniformity？ about simgrace HOT 6 OPEN

# bsz : batch size (number of positive pairs)
# d   : latent dim
# x   : Tensor, shape=[bsz, d]
#       latents for one side of positive pairs
# y   : Tensor, shape=[bsz, d]
#       latents for the other side of positive pairs

def align_metric(x, y, alpha=2):
    return (x - y).norm(p=2, dim=1).pow(alpha).mean()

def uniform_metric(x, t=2):
    return torch.pdist(x, p=2).pow(2).mul(-t).exp().mean().log()