test_n_pairs_mc_loss.py 文件源码

def check_forward(self, f_data, f_p_data, l2_reg):
        xp = cuda.get_array_module(f_data)
        num_examples = len(f_data)
        f = chainer.Variable(f_data)
        f_p = chainer.Variable(f_p_data)

        loss = n_pair_mc_loss(f, f_p, l2_reg)

        loss_for_each = []
        for i in range(num_examples):
            exps = []
            for j in set(range(num_examples)) - {i}:
                exp_ij = xp.exp(f_data[i].dot(f_p_data[j]) -
                                f_data[i].dot(f_p_data[i]))
                exps.append(exp_ij)
            loss_i = xp.log(1.0 + sum(exps))
            loss_for_each.append(loss_i)
        loss_expected = xp.asarray(loss_for_each, dtype=np.float32).mean()

        testing.assert_allclose(loss.data, loss_expected, atol=1e-2)