How can I ignore a data set if some column names don't exist in it?
I have a list of weather data from a stream but I think certain key weather conditions don't exist and therefore I have this error below with rbind
:
Error in rbind(deparse.level, ...) :
numbers of columns of arguments do not match
My code:
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$dailysummary
weatherDf <- rbind(weatherDf, ldply(
list(dailySummary),
function(x) c(airport, format(as.Date(date), "%Y-%m-%d"), x[["meanwindspdi"]], x[["meanwdird"]], x[["meantempm"]], x[["humidity"]])
))
}
So how can I make sure these key conditions below exist in the data:
meanwindspdi
meanwdird
meantempm
humidity
If any of them does not exit, then ignore the bunch of them. Is it possible?
EDIT:
The content of weatherData is in jsfiddle (I can't post it here as it is too long and I dunno where is the best place to show the data publicly for R...)
EDIT 2:
I get some error when I try to export the data into a txt:
> write.table(weatherData,"/home/teelou/Desktop/data/data.txt",sep="\t",row.names=FALSE)
Error in data.frame(date = list(pretty = "January 1, 1970", year = "1970", :
arguments imply differing number of rows: 1, 0
What does it mean? It seems that there are some errors in the data...
EDIT 3:
I have exported my entire data in .RData to my google drive:
https://drive.google.com/file/d/0B_w5RSQMxtRSbjdQYWJMX3pfWXM/view?usp=sharing
If you use RStudio, then you can just import the data.
EDIT 4:
target_names <- c("meanwindspdi", "meanwdird", "meantempm", "humidity")
# If it has data then loop it.
if (!is.null(weatherData)) {
# Initialize a data frame.
weatherDf <- data.frame()
for(i in weatherData) {
if (!all(target_names %in% names(i)))
next
# Get the airport code.
airport <- i$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]]))
}
Inspect the weatherDf
:
> View(weatherDf)
Error in .subset2(x, i, exact = exact) : subscript out of bounds
You can use next
to skip the current iteration of the loop and go to the next iteration:
target_names <- c("meanwindspdi", "meanwdird", "meantempm", "humidity")
for(i in weatherData) {
if (!all(target_names %in% names(i)))
next
# continue with loop...