如何解决时间(time <= time_end) {：在真/假需要时缺少值的错误？

Question

我以为我在逻辑语句中解释了NULL，但它仍然是一个错误。我不知道为什么。我无法删除数据中的NULL。Visual是一个数据，它包含一个时间值作为整数(即8:00 == 800)以及其他一些字符数据。final_1和final_2只是的空版本。我还需要为时间逻辑编写一些代码，这样当值达到60时，时间就会跳到100。

 for (i in 1:nrow(Visual)){
  time <- Visual[i,]$Start_Time
  time_end <- Visual[i,]$End_Time
  if(is.null(time)){
    time <- min_time
    if(is.null(time_end)){
      while(time <= max_time){
        final_2[i,]$Time <- time
        final_2[i,]$Appointment_AIM <- Visual[i,]$Appointment
        final_2[i,]$AIM_Abbreviation <- Visual[i,]$Abbreviation
        final_2[i,]$Standard_Duration <- Visual[i,]$Standard_Duration
        final_2[i,]$Booking_Factor <- Visual[i,]$Booking_Factor
        final_2[i,]$Appointment_Categories_ACM <- Visual[i,]$Appointment_Categories
        final_2[i,]$ACM_Abbreviation <- Visual[i,]$ACM_Abbreviation
        final_2[i,]$Color_Code <- Visual[i,]$Color_Code
        final_1 <- rbind(final_1, final_2)
        time <- time + Visual[i,]$Standard_Duration
      }
    }else{
      while(time <= time_end){
        final_2[i,]$Time <- time
        final_2[i,]$Appointment_AIM <- Visual[i,]$Appointment
        final_2[i,]$AIM_Abbreviation <- Visual[i,]$Abbreviation
        final_2[i,]$Standard_Duration <- Visual[i,]$Standard_Duration
        final_2[i,]$Booking_Factor <- Visual[i,]$Booking_Factor
        final_2[i,]$Appointment_Categories_ACM <- Visual[i,]$Appointment_Categories
        final_2[i,]$ACM_Abbreviation <- Visual[i,]$Abbreviation
        final_2[i,]$Color_Code <- Visual[i,]$Color_Code
        final_1 <- rbind(final_1, final_2)
        time <- time + Visual[i,]$Standard_Duration
      }
    }
  }else{
    if(is.null(time_end)){
      while(time <= max_time){
        final_2[i,]$Time <- time
        final_2[i,]$Appointment_AIM <- Visual[i,]$Appointment
        final_2[i,]$AIM_Abbreviation <- Visual[i,]$Abbreviation
        final_2[i,]$Standard_Duration <- Visual[i,]$Standard_Duration
        final_2[i,]$Booking_Factor <- Visual[i,]$Booking_Factor
        final_2[i,]$Appointment_Categories_ACM <- Visual[i,]$Appointment_Categories
        final_2[i,]$ACM_Abbreviation <- Visual[i,]$Abbreviation
        final_2[i,]$Color_Code <- Visual[i,]$Color_Code
        final_1 <- rbind(final_1, final_2)
        time <- time + Visual[i,]$Standard_Duration
      }
    }else{
      while(time <= time_end){
        final_2[i,]$Time <- time
        final_2[i,]$Appointment_AIM <- Visual[i,]$Appointment
        final_2[i,]$AIM_Abbreviation <- Visual[i,]$Abbreviation
        final_2[i,]$Standard_Duration <- Visual[i,]$Standard_Duration
        final_2[i,]$Booking_Factor <- Visual[i,]$Booking_Factor
        final_2[i,]$Appointment_Categories_ACM <- Visual[i,]$Appointment_Categories
        final_2[i,]$ACM_Abbreviation <- Visual[i,]$Abbreviation
        final_2[i,]$Color_Code <- Visual[i,]$Color_Code
        final_1 <- rbind(final_1, final_2)
        time <- time + Visual[i,]$Standard_Duration
      }
    }
  }
}

Answer 1

注意NAs和NULL值之间的区别。选择下列表达式的输出：

is.null(NA)
[1] FALSE


while(NA) {TRUE}
"Error in while (NA) { : missing value where TRUE/FALSE needed"

如果我们正在寻找需要嵌套if/else或ifelse的条件转换，那么我们最好使用dplyr::case_when。