[{'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 dccGARCH(returns):\ncov_matrix=np.cov(returns)\ndiag=cov_matrix.diagonal()\ndiag_matrix=np.diag(np.diag(cov_matrix))\ngarch11 = arch_model(diag, p=1, q=1)\nres = garch11.fit(update_freq=10)\nalpha=res.params[2]\nbeta=res.params[3]\nesubt.append(np.matmul(np.linalg.inv(diag_matrix),returns))\nqdash=np.cov(esubt[-2])\nq_list.append(((1-alpha-beta)*qdash) +\n(alpha*np.matmul(esubt[-2],esubt[-2].T)) + ((beta)*q_list[-1]))\nqstar=np.diag(np.diag(cov_matrix))\nqstar=np.sqrt(qstar)\nr=np.matmul(np.linalg.inv(qstar),q_list[-1],np.linalg.inv(qstar))\npred_cov_temp=np.matmul(diag_matrix,r)\npred_cov.append(np.matmul(pred_cov_temp,diag_matrix))'}, {'role': 'assistant', 'content': 'modelling'}]