这在 R 中对我有用：
# Setting up the first inner while-loop controller, the start of the next water year
NextH2OYear <- as.POSIXlt(firstDate)
NextH2OYear$year <- NextH2OYear$year + 1
NextH2OYear<-as.Date(NextH2OYear)
但这不会：
# Setting up the first inner while-loop controller, the start of the next water month
NextH2OMonth <- as.POSIXlt(firstDate)
NextH2OMonth$mon <- NextH2OMonth$mon + 1
NextH2OMonth <- as.Date(NextH2OMonth)
我收到此错误：
as.Date.POSIXlt(NextH2OMonth) 中的错误：非空 POSIXlt 结构中的零长度分量
任何想法为什么？我需要系统地添加一年（对于一个循环）和一个月（对于另一个循环），并将生成的更改变量与 Date 类的值进行比较，这就是使用 as.Date() 将它们转换回的原因。
谢谢，汤姆
编辑：
下面是整个代码部分。我正在使用 RStudio（版本 0.97.306）。下面的代码表示一个函数，它传递了一个包含两列（日期（CLass=Date）和排放数据（Class=Numeric））的数组，用于计算每月平均值。因此，firstDate 和 lastDate 是类 Date 并由传递的数组。此代码改编自计算年度平均值的成功代码 - 可能还有一两件事我仍然需要更改，但由于我在使用 POSIXlt 时遇到的早期错误，我无法检查后面的部分. 这里是代码：
MonthlyAvgDischarge<-function(values){
#determining the number of values - i.e. the number of rows
dataCount <- nrow(values)
# Determining first and last dates
firstDate <- (values[1,1])
lastDate <- (values[dataCount,1])
# Setting up vectors for results
WaterMonths <- numeric(0)
class(WaterMonths) <- "Date"
numDays <- numeric(0)
MonthlyAvg <- numeric(0)
# while loop variables
loopDate1 <- firstDate
loopDate2 <- firstDate
# Setting up the first inner while-loop controller, the start of the next water month
NextH2OMonth <- as.POSIXlt(firstDate)
NextH2OMonth$mon <- NextH2OMonth$mon + 1
NextH2OMonth <- as.Date(NextH2OMonth)
# Variables used in the loops
dayCounter <- 0
dischargeTotal <- 0
dischargeCounter <- 1
resultsCounter <- 1
loopCounter <- 0
skipcount <- 0
# Outer while-loop, controls the progression from one year to another
while(loopDate1 <= lastDate)
{
# Inner while-loop controls adding up the discharge for each water year
# and keeps track of day count
while(loopDate2 < NextH2OMonth)
{
if(is.na(values[resultsCounter,2]))
{
# Skip this date
loopDate2 <- loopDate2 + 1
# Skip this value
resultsCounter <- resultsCounter + 1
#Skipped counter
skipcount<-skipcount+1
} else{
# Adding up discharge
dischargeTotal <- dischargeTotal + values[resultsCounter,2]
}
# Adding a day
loopDate2 <- loopDate2 + 1
#Keeping track of days
dayCounter <- dayCounter + 1
# Keeping track of Dicharge position
resultsCounter <- resultsCounter + 1
}
# Adding the results/water years/number of days into the vectors
WaterMonths <- c(WaterMonths, as.Date(loopDate2, format="%mm/%Y"))
numDays <- c(numDays, dayCounter)
MonthlyAvg <- c(MonthlyAvg, round((dischargeTotal/dayCounter), digits=0))
# Resetting the left hand side variables of the while-loops
loopDate1 <- NextH2OMonth
loopDate2 <- NextH2OMonth
# Resetting the right hand side variable of the inner while-loop
# moving it one year forward in time to the next water year
NextH2OMonth <- as.POSIXlt(NextH2OMonth)
NextH2OMonth$year <- NextH2OMonth$Month + 1
NextH2OMonth<-as.Date(NextH2OMonth)
# Resettting vraiables that need to be reset
dayCounter <- 0
dischargeTotal <- 0
loopCounter <- loopCounter + 1
}
WaterMonths <- format(WaterMonthss, format="%mm/%Y")
# Uncomment the line below and return AvgAnnualDailyAvg if you want the water years also
# AvgAnnDailyAvg <- data.frame(WaterYears, numDays, YearlyDailyAvg)
return((MonthlyAvg))
}
常规 R 中也会出现同样的错误。当逐行执行时，它不是问题，当它作为脚本运行时，它就是它。