Hi Heather thanks for this. (I have messed up quote level somewhere. Sorry for that).
On Jun 20, 2005, at 02:01 pm, Heather Turner wrote: > >>>> Robin Hankin <[EMAIL PROTECTED]> 06/20/05 10:32am >>> >> Hi >> >> [snip] >> I would expect sweep() to give >> me a warning if the elements don't recycle nicely > [snip] > >> behave as expected, But >> >> >> sweep(X,1,1:5,"+") >> >> and >> >> sweep(X,2,1:5,"+") >> >> >> >> are identical! >> > ...which is also expected since the matrix is square. Perhaps the >> following will help you see why: > > matrix(1:5,6,6) > matrix(1:5,6,6, byrow = TRUE) Yes, after thinking about your example for a few minutes, it was a bit foolish of me to use a square matrix to illustrate this problem. Thinking about it, it is the coincidence that ncol(X) %% n == nrow(X)%%n == 1 that caused the phenomenon I remarked on [here n=length(x)]. I should have known better, as I use this phenomenon deliberately in magic square construction! (although not by using sweep()). > I agree with your main point however, it would be useful if 'sweep' > would give a warning when the length of the vector of statistics to be > swept out was not a sub-multiple or multiple of the corresponding array > dimension. yes, that would be good. Can anyone think of a situation in which one would want to ignore such a warning? Conversely, does anyone deliberately use sweep() with non-recycling vector? > -- Robin Hankin Uncertainty Analyst National Oceanography Centre, Southampton European Way, Southampton SO14 3ZH, UK tel 023-8059-7743 ______________________________________________ R-help@stat.math.ethz.ch mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
