regression_stealer.py 文件源码

def find_coeffs_bin(self, budget):
        k = len(self.classes)       # number of classes
        assert k == 2
        n = self.num_features()     # vector dimension

        X_train = self.gen_query_set(n, budget)
        y = logit(self.query_probas(X_train)[:, 1])

        X = np.hstack((X_train, np.ones((budget, 1))))

        if budget == n+1:
            try:
                w_opt = np.linalg.solve(X, y).T
            except np.linalg.linalg.LinAlgError:
                w_opt = np.linalg.lstsq(X, y)[0].T
        else:
            w_opt = np.linalg.lstsq(X, y)[0].T

        int_opt = w_opt[-1]
        w_opt = np.array([w_opt[:-1]])

        self.X_train = X_train

        return w_opt, int_opt