dates
is a 1-column data.frame. as.Date
and xts' order.by
argument require vectors.
births <- xts(births, dates$Month)
문제
births and dates are from same file and share same length.
format of dates seems to be good. But xts
cannot recogize it as date,why?! Thanks for your help!
dates <- read.xlsx("TimeSeriesCourseworkData.xls", 1,colIndex=1,as.data.frame=TRUE)
dates
Month
1 2009-01-01
2 2009-02-01
3 2009-03-01
4 2009-04-01
............
26 2011-02-01
27 2011-03-01
28 2011-04-01
29 2011-05-01
30 2011-06-01
births <- xts(births, order.by = dates)
# Error in xts(births, order.by = dates) :
# order.by requires an appropriate time-based object
births <- xts(births, order.by = as.Date(dates))
# Error in as.Date.default(dates) :
# do not know how to convert 'dates' to class “Date”
해결책
dates
is a 1-column data.frame. as.Date
and xts' order.by
argument require vectors.
births <- xts(births, dates$Month)