What is the `.xts` constructor/how does it work?
r, xts
Solution
No, `.xts` is not any kind of standard. `.xts` is mainly for internal use, but it's exported for convenience. `.xts` differs from `xts` in that `xts` requires `order.by` be time-based, whereas `.xts` expects `index` (its second argument, akin to `order.by`) to be numeric.
This is because the `index` attribute of xts objects is stored internally as a numeric vector with `tclass` and `tzone` attributes.
Problem
I am familiar with `as.xts` and `xts` as ways to create an `xts` object. I have just come across `.xts` as used in the following: ``` > x <- .xts(1:3,60*1:3) > is.xts(x) [1] TRUE > x [,1] 1970-01-01 01:01:00 1 1970-01-01 01:02:00 2 1970-01-01 01:03:00 3 ``` However, I can't find anything about it in the documentation. I note that the same arguments as in the example above would not work for `as.xts` or `xts`. Is `.xts` some kind of standard R construction?