I am using zoo objects, buy my question also applies to xts objects. It looks to me like it is a one column vector with an index. In my case the index is the vector of dates and the one column vector my data. All is good except that I would like to access the dates (from the index).
For example I have the following result:
ObjZoo <- structure(c(10, 20), .Dim = c(2L, 1L), index = c(14788, 14789),
class = "zoo", .Dimnames = list(NULL, "Data"))
unclass(ObjZoo)
# Data
# [1,] 10
# [2,] 20
# attr(,"index")
# [1] 14788 14789
I want to get 14789 in a variable or a vector, but I'm not sure how to access it.
Answer
From the help for ?zoo, there are two convenience methods to access the data in zoo objects:
coredata()returns the data in the zoo objectindex()returns the index
For example:
x.Date <- as.Date("2003-02-01") + c(1, 3, 7, 9, 14) - 1
x <- zoo(rnorm(5), x.Date)
index(x)
[1] "2003-02-01" "2003-02-03" "2003-02-07" "2003-02-09" "2003-02-14"
coredata(x)
[1] -1.2487943 0.8911630 1.2713133 -0.1024638 0.2989194