Sure,
You can see the loss function in here: https://www.dropbox.com/s/2kh8lnkrt41rgbv/lslrrd_pytorch.py?dl=0 176
which seems pretty complicated (sorry about that).
I also have my own norm functions as follow:
def get_fib_norm(A):
    B = torch.sqrt(torch.trace(torch.mm(torch.transpose(A,0,1),A)))
    return B
def get_nuc_norm(A):
    B = torch.trace(torch.sqrt(torch.mm(A,A)))
    return B
def get_infinity_norm(A):
    B = torch.max(torch.sum(torch.abs(A),dim=1))
    return B
def get_spec_norm(A):
    l1, B, l2 = torch.svd(A,some=False)
    C = torch.max(B)
    return C