def loss_func()

in utils.py [0:0]

• 4 lines of code
• 1 McCabe index (conditional complexity)

def loss_func(probs, Q_mat):
    """
    Function to compute cost value for given probability of spin [prob(+1)] and predefined Q matrix.

    Input:
        probs: Probability of each node belonging to each class, as a vector
        Q_mat: QUBO as torch tensor
    """

    probs_ = torch.unsqueeze(probs, 1)

    # minimize cost = x.T * Q * x
    cost = (probs_.T @ Q_mat @ probs_).squeeze()

    return cost