收到此错误：没有适用于'mutate_'的适用方法应用于类“ c（'integer'，'numeric'）”的对象

Question

在r函数中操作数据框时出现此错误。代码如下所示：

daysMaintenance <- function(tid, make, component){

      df <- read.csv(paste(sep="","normal/turbine_",tid,"_running.csv"),header=T)


  check_date <- "2008-11-1"

  df <- df[,c("Time_min")]

  df <- df %>% mutate(Day = as.integer(Time_min/1445) + 1)
  df <- df %>% group_by(Day) %>% summarise_at(vars(c(Time_min)), funs(max))

  df <- df %>% mutate(Date = (as.Date(check_date) + df$Day - 1))

  full.list = seq(from = as.Date(min(df$Date)), to = as.Date(max(df$Date)), by = 1)

  diffs <- full.list[!full.list %in% df$Date]
  diffs <- data.frame(diffs)
  colnames(diffs) <- c("no_data_Date") 
  return (diffs)
}

为什么会出现此错误以及如何解决？预先谢谢你。