如果数据集中不存在某些列名,我该如何忽略它?
我有一个来自流的天气数据列表,但我认为某些关键天气状况不存在,因此我在rbind
下面出现此错误:
Error in rbind(deparse.level, ...) :
numbers of columns of arguments do not match
我的代码:
weatherDf <- data.frame()
for(i in weatherData) {
# Get the airport code.
airport <- i$airport
# Get the date.
date <- as.POSIXct(as.numeric(as.character(i$timestamp))/1000, origin="1970-01-01", tz="UTC-1")
# Get the data in dailysummary only.
dailySummary <- i$dailysummary
weatherDf <- rbind(weatherDf, ldply(
list(dailySummary),
function(x) c(airport, format(as.Date(date), "%Y-%m-%d"), x[["meanwindspdi"]], x[["meanwdird"]], x[["meantempm"]], x[["humidity"]])
))
}
那么如何确保数据中存在以下关键条件:
meanwindspdi
meanwdird
meantempm
humidity
如果任何没有退出,那么忽略一堆。有可能吗?
修改
weatherData的内容在jsfiddle(我不能在这里发布,因为它太长了,我不知道哪里是向R公开显示数据的最佳位置...)
编辑2:
当我尝试将数据导出到txt时出现错误:
> write.table(weatherData,"/home/teelou/Desktop/data/data.txt",sep="\t",row.names=FALSE)
Error in data.frame(date = list(pretty = "January 1, 1970", year = "1970", :
arguments imply differing number of rows: 1, 0
这是什么意思?似乎数据中存在一些错误......
编辑3:
我已将.RData中的所有数据导出到我的google驱动器:
https://drive.google.com/file/d/0B_w5RSQMxtRSbjdQYWJMX3pfWXM/view?usp=sharing
如果您使用RStudio,那么您只需导入数据。
编辑4:
target_names <- c("meanwindspdi", "meanwdird", "meantempm", "humidity")
# If it has data then loop it.
if (!is.null(weatherData)) {
# Initialize a data frame.
weatherDf <- data.frame()
for(i in weatherData) {
if (!all(target_names %in% names(i)))
next
# Get the airport code.
airport <- i$airport
# Get the date.
date <- as.POSIXct(as.numeric(as.character(i$timestamp))/1000, origin="1970-01-01", tz="UTC-1")
# Get the data in dailysummary only.
dailySummary <- i$dailysummary
weatherDf <- rbind(weatherDf, ldply(
list(dailySummary),
function(x) c(airport, format(as.Date(date), "%Y-%m-%d"), x[["meanwindspdi"]], x[["meanwdird"]], x[["meantempm"]], x[["humidity"]])
))
}
# Rename column names.
colnames(weatherDf) <- c("airport", "key_date", "ws", "wd", "tempi", 'humidity')
# Convert certain columns weatherDf type to numberic.
columns <-c("ws", "wd", "tempi", "humidity")
weatherDf[, columns] <- lapply(columns, function(x) as.numeric(weatherDf[[x]]))
}
检查weatherDf
:
> View(weatherDf)
Error in .subset2(x, i, exact = exact) : subscript out of bounds
答案 0 :(得分:1)
您可以使用next
跳过循环的当前迭代并转到下一次迭代:
target_names <- c("meanwindspdi", "meanwdird", "meantempm", "humidity")
for(i in weatherData) {
if (!all(target_names %in% names(i)))
next
# continue with loop...