integer data frame to date in R -


i have data frame 10 dates read r integers. here data frame:

19820509 19550503 20080505 19590505 19940517 19690504 20050420 20060503 19840427 19550513

we'll called df.

i have attempted few different lines of code here change each value date format in r this: "1982-05-09"

df <-  as.date(df, "%y%m%d")

doesn't work , neither 

 df <- as.posixlt(df, format = "%y/%m/%d")

or

df <- as.posixct(df), format = "%y/%m/%d", origin = "19820509")

i keep getting error saying "do not know how convert 'df' class "date" or either of posix formats.

i thought more simple. ideas?

thank you.

you have reference specific columns rather referencing data frame. if variable containing integer dates in data frame df , called x, can this:

df <- transform(df, x = as.date(as.character(x), "%y%m%d"))  #             x #  1 1982-05-09 #  2 1955-05-03 #  3 2008-05-05 #  4 1959-05-05 #  5 1994-05-17 #  6 1969-05-04 #  7 2005-04-20 #  8 2006-05-03 #  9 1984-04-27 # 10 1955-05-13

this converts integers character strings, interprets strings dates.

if multiple columns containing dates in format, can convert them in 1 fell swoop, have differently:

df <- data.frame(lapply(df, function(x) as.date(as.character(x), "%y%m%d")))

or better, docendo discimus mentioned in comment:

df[] <- lapply(df, function(x) as.date(as.character(x), "%y%m%d"))

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