def _L1_reg(self, lambda_, w1, w2):
        return ((lambda_ / 2.0) * (np.abs(w1[:, 1:]).sum() +
                np.abs(w2[:, 1:]).sum()))
Compute L1-regularization cost.
dataset/ETHPy150Open rasbt/mlxtend/mlxtend/classifier/neuralnet_mlp.py/NeuralNetMLP._L1_reg