R-聚合函数创建子列表

我正在使用聚合函数来总结一些数据。数据是贷款数据，我有ContractNum和LoanAmount。我想按StartDate汇总数据，计算贷款数量并平均贷款金额。 以下是我使用的数据和函数示例：

ContractNum <- c("RHL-1","RHL-2","RHL-3","RHL-3")
StartDate <- c("2016-11-01","2016-11-01","2016-12-01","2016-12-01")
LoanPurpose <- c("Personal","Personal","HomeLoan","Investment")
LoanAmount <- c(200,500,600,150)

dat <- data.frame(ContractNum,StartDate,LoanPurpose,LoanAmount)



 aggr.data <- aggregate(
  cbind(LoanAmount,ContractNum) ~ StartDate + LoanPurpose  
  ,data = dat
  ,FUN = function(x)c(count = mean(x),length(x))
)

但当我看到它的结构时，它似乎创建了一个子列表：

> str(aggr.data)
'data.frame':   3 obs. of  4 variables:
 $ StartDate  : Factor w/ 2 levels "2016-11-01","2016-12-01": 2 2 1
 $ LoanPurpose: Factor w/ 3 levels "HomeLoan","Investment",..: 1 2 3
 $ LoanAmount : num [1:3, 1:2] 600 150 350 1 1 2
  ..- attr(*, "dimnames")=List of 2
  .. ..$ : NULL
  .. ..$ : chr  "count" ""
 $ ContractNum: num [1:3, 1:2] 3 3 1.5 1 1 2
  ..- attr(*, "dimnames")=List of 2
  .. ..$ : NULL
  .. ..$ : chr  "count" ""

我如何摆脱这个子列表，以便能够以通常访问DF的方式访问每个列？我知道在代码中我要求给我一个ContractNum的平均值，这是没有意义的，但是我可以去掉这个列

谢谢

只需执行do.calldata.frame。。。在aggr.data上取消对矩阵的测试

aggr.data <- do.call(data.frame, aggr.data);
str(aggr.data);
#'data.frame':  3 obs. of  6 variables:
# $ StartDate        : Factor w/ 2 levels "2016-11-01","2016-12-01": 2 2 1
# $ LoanPurpose      : Factor w/ 3 levels "HomeLoan","Investment",..: 1 2 3
# $ LoanAmount.count : num  600 150 350
# $ LoanAmount.V2    : num  1 1 2
# $ ContractNum.count: num  3 3 1.5
# $ ContractNum.V2   : num  1 1 2

---

为什么会被否决？您的示例代码可能不起作用？制作aggr.data时，您有一个额外的参数。顺便说一句，我不是最悲观的选民。

aggr.data <- do.call(data.frame, aggr.data);
str(aggr.data);
#'data.frame':  3 obs. of  6 variables:
# $ StartDate        : Factor w/ 2 levels "2016-11-01","2016-12-01": 2 2 1
# $ LoanPurpose      : Factor w/ 3 levels "HomeLoan","Investment",..: 1 2 3
# $ LoanAmount.count : num  600 150 350
# $ LoanAmount.V2    : num  1 1 2
# $ ContractNum.count: num  3 3 1.5
# $ ContractNum.V2   : num  1 1 2