如何将R函数特定报错替换为「尝试其他种子范围」指引？

问题场景 #

• 调用参数abc(a = 280000, z = 281000, n = 10, p = 1, d = 0, q = 0, ar11 = 0.8, sd = 1, j1 = 4, arr1 = "0.80")时触发报错：Error in order(res2$seed): argument 1 is not a vector
• 更换种子范围（如a = 289800, z = 289989）后可正常返回预期数据框

错误根源 #

当指定的种子范围内没有符合筛选条件的结果时，res1会变成空列表。后续通过Reduce合并空列表会生成无seed列的空对象，调用order(res2$seed)时因找不到有效向量触发报错。

修改后的函数代码 #

abc <- function(a, z, n, ar11, p, d, q, sd = sd, j1, arr1, n_cores){
  future::plan(future::multisession)
  n_cores <- parallel::detectCores()
  cl <- parallel::makeCluster(n_cores)
  doParallel::registerDoParallel(cores = n_cores)

  message('processing...')
  `%dopar%` <- foreach::`%dopar%`
  res <- foreach::foreach(i = a:z, .packages = c('foreach', 'forecast')) %dopar% {
    set.seed(i)
    mod <- stats::arima.sim(n = n, model = list(ar = c(ar11), order = c(p, d, q)), sd = sd)
    best.mod <- forecast::auto.arima(mod, ic = "aicc")
    cf <- best.mod$coef
    if (length(cf) == 0) {
      rep(NA, 2)
    } else if (all(grepl(c("ar1|intercept"), names(cf))) &
               substr(cf["ar1"], 1, j1) %in% arr1) {
      c(cf, seed = i)
    } else {
      rep(NA, 2)
    }
  }
  message(' done!\n')

  res1 <- res[!sapply(res, anyNA)]

  parallel::stopCluster(cl)
  options(max.print = .Machine$integer.max)

  # 新增空结果判断与错误捕获
  if (length(res1) == 0) {
    message("请尝试其他种子范围")
    return(tibble::tibble())
  }

  res2 <- Reduce(function(...) merge(..., all = T), lapply(res1, function(x) as.data.frame(t(x))))
  
  # 用tryCatch捕获排序报错
  tryCatch({
    res2[order(res2$seed), ]
  }, error = function(e) {
    if (grepl("argument 1 is not a vector", e$message)) {
      message("请尝试其他种子范围")
    }
    return(res2)
  })
}

修改说明 #

1. 前置空结果判断：先检查res1是否为空，直接提示用户更换种子范围并返回空数据框，避免后续无效运算
2. 排序阶段错误捕获：用tryCatch包裹排序逻辑，精准匹配目标报错信息并输出指引
3. 冗余代码清理：移除原函数中重复的res2赋值语句，优化代码结构

内容的提问来源于stack exchange，提问作者Daniel James