汇总函数中的错误：找不到对象“ n”

Question

我正在尝试将R中的聚合命令与数据“犯罪”一起使用。 但是，当我尝试执行命令时，仍然出现此错误：

Error in FUN(X[[i]], ...) : object 'n' not found

我的代码如下：

crime<-read.csv("Crime_Reports.csv")



larcperneighborhood<-aggregate(crime, by=list(Larceny,Neighborhood), FUN = sum)
Error in FUN(X[[i]], ...) : object 'n' not found

vcoccurance<-aggregate(crime, by=list(DOJ.Violent.Crime,Neighborhood), FUN = sum)
Error in FUN(X[[i]], ...) : object 'n' not found

theftperneighborhood<-aggregate(crime, by=list(Theft,Neighborhood), FUN = sum)
Error in FUN(X[[i]], ...) : object 'n' not found

felperneighborhood<-aggregate(crime, by=list(Felony,Neighborhood), FUN = sum)
Error in FUN(X[[i]], ...) : object 'n' not found

我不确定下一步是什么，我无法在数据中找到'n'。 谢谢！