[{'role': 'system', 'content': "You are an expert in machine learning and your task is to classify code snippets into one of the following categories: ['helper_functions', 'load_data', 'data_exploration', 'data_preprocessing', 'evaluation', 'modelling', 'prediction', 'result_visualization', 'save_results', 'comment_only']."}, {'role': 'user', 'content': 'Identify the single most appropriate category to which the provided code belongs. Provide your response as a single category label without any additional information, commentary, or personal opinions.\\nPython Code:def regression_gradient_descent(features_matrix, output, initial_weights, step_size, tolerance):\nconverged = False\nweights = np.array(initial_weights)\nwhile not converged:\npredictions = predict_outcome(features_matrix, weights)\nerrors = predictions - output\ngradient_sum_squares = 0\nfor i in range(len(weights)):\nderivative = feature_derivative(errors, features_matrix[:, i])\ngradient_sum_squares += derivative ** 2\nweights[i] -= step_size * derivative\ngradient_magnitude = math.sqrt(gradient_sum_squares)\nif(gradient_magnitude < tolerance):\nconverged = True\nreturn (weights)'}, {'role': 'assistant', 'content': 'modelling'}]