[R] How can I map by results to original list of indices or first difference of column of data.frame with two factors?

Hello! I’m having stacked data in a data.frame with 2 factors, ordered POSIXct, and actual value as numeric (as if for lattice::xyplot). I would like to calculate first difference using “diff” function within corresponding subsets/partitions. Since data.frame is organized by factors and has

Re: [R] How can I map by results to original list of indices or first difference of column of data.frame with two factors?

If you would post a subset of your data so that we can see what you are talking about, we could probably help you come up with a solution. On Sat, Mar 3, 2012 at 7:50 PM, Mikhail Titov m...@gmx.us wrote: Hello! I’m having stacked data in a data.frame with 2 factors, ordered POSIXct, and

Re: [R] How can I map by results to original list of indices or first difference of column of data.frame with two factors?

It'd be doubly helpful if you could post desired output as well. If you haven't seen it before, the easiest way to post R data is to use the dput() function to get a plain-text (mailing list friendly) representation. If your data is large, dput(head(DATA, 30)) should suffice. (We wouldn't want

Re: [R] How can I map by results to original list of indices or first difference of column of data.frame with two factors?

R. Michael Weylandt michael.weyla...@gmail.com writes: It'd be doubly helpful if you could post desired output as well. I beg alls pardon, I suddenly realized that in my case the solution is trivial. Here is an example with a mock-up data. Let's generate some data #+begin_src R qq -