def test_evaluate(self):
        """ test evaluate. """

        quadratic_program = QuadraticProgram()
        x = [quadratic_program.continuous_var() for _ in range(5)]

        coefficients_list = list(range(5))
        linear = LinearExpression(quadratic_program, coefficients_list)

        values_list = list(range(len(x)))
        values_array = np.array(values_list)
        values_dict_int = {i: i for i in range(len(x))}
        values_dict_str = {'x{}'.format(i): i for i in range(len(x))}

        for values in [
                values_list, values_array, values_dict_int, values_dict_str
        ]:
            self.assertEqual(linear.evaluate(values), 30)
    def test_get_item(self):
        """ test get_item. """

        quadratic_program = QuadraticProgram()
        for _ in range(5):
            quadratic_program.continuous_var()

        coefficients = list(range(5))
        linear = LinearExpression(quadratic_program, coefficients)
        for i, v in enumerate(coefficients):
            self.assertEqual(linear[i], v)
    def test_setters(self):
        """ test setters. """

        quadratic_program = QuadraticProgram()
        for _ in range(5):
            quadratic_program.continuous_var()

        zeros = np.zeros(quadratic_program.get_num_vars())
        linear = LinearExpression(quadratic_program, zeros)

        coefficients_list = list(range(5))
        coefficients_array = np.array(coefficients_list)
        coefficients_dok = dok_matrix([coefficients_list])
        coefficients_dict_int = {i: i for i in range(1, 5)}
        coefficients_dict_str = {'x{}'.format(i): i for i in range(1, 5)}

        for coeffs in [
                coefficients_list, coefficients_array, coefficients_dok,
                coefficients_dict_int, coefficients_dict_str
        ]:
            linear.coefficients = coeffs
            self.assertEqual((linear.coefficients != coefficients_dok).nnz, 0)
            self.assertTrue((linear.to_array() == coefficients_list).all())
            self.assertDictEqual(linear.to_dict(use_name=False),
                                 coefficients_dict_int)
            self.assertDictEqual(linear.to_dict(use_name=True),
                                 coefficients_dict_str)