[Rd] Subsetted 1-D arrays (PR#4110)
brahm at alum.mit.edu
Wed Oct 22 00:25:50 MEST 2003
In R-patched_2003-10-20, subsetted 1-D arrays no longer get converted to
vectors. The NEWS file documents this change, as an indirect result of bug
report 4110. I just wanted to mention this can break code in some rather
obscure ways, such as this toy example:
R> x <- sort(tapply(1:8, rep(1:4,2), sum)) # Was vector, now is 1D array
R> y <- matrix(1:4, 1,4) # 1x4 matrix
R> x + y # Used to return a 1x4 matrix
Error in x + y : non-conformable arrays
I agree with the change, but I would beware that some puzzled users may not
associate new "tapply problems" with this news item.
Also, *should* you be able to add a (4) array to a (1,4) array?
-- David Brahm (brahm at alum.mit.edu)
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