Wrong move of NEWS item

Then, please announce the change in NEWS. For example:
The result of arithmetic and comparison operations of non-overlapping "ts" objects where either is a matrix is now a matrix.

It seems that the statement "diff(<ts-matrix>) remains matrix, even when it has length zero" was meant for the change to 'Ops.ts'. But the wording is about diff(<ts-matrix>), which is included in the previous statement.

But I've just realized this.
Suppose that
x <- ts(0)
With the change, x - lag(x, -1) and x == lag(x, -1) are NULL.
In R 4.5.2, x - lag(x, -1) is integer(0) and x == lag(x, -1) is logical(0).

________

Peter Dalgaard
? ? on Mon, 2 Mar 2026 14:37:22 +0100 writes:

? ? > I do hope Martin sees this. Code freeze for 4.5.3 is
? ? > Wednesday @0:02 ...? - Peter


Yes, I did see and think about it, but decided that it was "too
late" now, *and* not a "problem" I think:
`-` now exhibits the correct behaviour? but the diff()
? ? methods do not yet (but do in R-devel etc).

Martin

? ? >> On 28 Feb 2026, at 12.57, Suharto Anggono Suharto Anggono

? ? >>
? ? >> Now that the NEWS item is gone from "CHANGES IN R 4.5.2
? ? >> patched", please also revert the change to 'Ops.ts' in
? ? >> R-4-5-branch, as I have mentioned. In R-4-5-branch, the
? ? >> change makes diff(m) inconsistent with m - lag(m, -1) for
? ? >> 1-row ts matrix m. Previously, neither of them was a
? ? >> matrix.
? ? >>
? ? >> _______ On Monday, 23 February 2026 at 07:16:36 pm GMT+7,

? ? >>
? ? >>
? ? >>>>>>> Suharto Anggono Suharto Anggono via R-devel on Sun,
? ? >>>>>>> 22 Feb 2026 03:58:13 +0000 (UTC) writes:
? ? >>
? ? >> > diff(m, lag, dif) for matrix m now still returns >
? ? >> matrices, also when lag * dif > nrow(m) (PR#18972, thanks
? ? >> to > Mikael Jagan and Suharto Anggono).? >
? ? >> diff(<ts-matrix>) remains matrix, even when it has length
? ? >> zero.
? ? >>
? ? >> > The above NEWS item has been moved to "CHANGES IN R
? ? >> 4.5.2 patched".
? ? >>
? ? >> > In fact, in R-4-5-branch, diff(m, lag, dif) for matrix
? ? >> m is still not a matrix when lag * dif > nrow(m) (see
? ? >> https://svn.r-project.org/R/branches/R-4-5-branch/src/library/base/R/diff.R
? ? >> for 'diff.default';
? ? >> https://svn.r-project.org/R/branches/R-4-5-branch/src/library/base/R/datetime.R
? ? >> for 'diff.POSIXt';
? ? >> https://svn.r-project.org/R/branches/R-4-5-branch/src/library/base/R/dates.R
? ? >> for 'diff.Date';
? ? >> https://svn.r-project.org/R/branches/R-4-5-branch/src/library/stats/R/ts.R
? ? >> for 'diff.ts').
? ? >>
? ? >> > And I suggest keeping it so. Because it has been like
? ? >> that simce the beginning, I think changing it in a patch
? ? >> release is not appropriate.
? ? >>
? ? >> We have ported bug fixes of "forever bugs" to the "R
? ? >> patched branch", before, quite on purpose.? Typically
? ? >> they have been really rare use cases and for that reason
? ? >> probably were not detected and reported earlier... and we
? ? >> (R core) still thought these bugs should disappear as
? ? >> quickly as possible.
? ? >>
? ? >> For the above reason(s), I *had* actually planned to port
? ? >> this bug fix also to R "4.5.2 patched" ...? But then it
? ? >> has become somewhat late to do the port only now, and R
? ? >> 4.5.3 will only be a "wrap up" release anyway..
? ? >>
? ? >> Hence, I agree with your opinion and will now move the
? ? >> NEWS entry instead of porting the bug fix which was the
? ? >> original plan.
? ? >>
? ? >> Martin
? ? >>
? ? >>
? ? >> > What have been ported to R-4-5-branch are just-
? ? >> replacing 'tsLag' with 'lag' in 'diff.ts'- 'Ops.ts' to
? ? >> return matrix when e1 or e2 is matrix but e1 and e2 are
? ? >> not overlapping > I suggest reverting the port. A
? ? >> justification of diff(m) for 1-row ts matrix m not being
? ? >> a matrix was that m - lag(m, -1) was not a matrix.? >
? ? >> Replacing 'tsLag' with 'lag' in 'diff.ts' is actually OK,
? ? >> but not necessary.
? ? >>
? ? >> [[alternative HTML version deleted]]
? ? >>
? ? >> ______________________________________________
? ? >> R-devel at r-project.org mailing list
? ? >> https://stat.ethz.ch/mailman/listinfo/r-devel


? ? > --
? ? > Peter Dalgaard, Professor, Center for Statistics,
? ? > Copenhagen Business School Solbjerg Plads 3, 2000
? ? > Frederiksberg, Denmark Phone: (+45)38153501 Office: A 4.23
? ? > Email: pd.mes at cbs.dk Priv: PDalgd at gmail.com