I guess that the matrix dimension changed because matrix in R are filled by columns. Since you try: apply(b, 1, function(y) sort(y, na.last=F)) The second parameter make it scan matrix b row by row but store result by columns, which make the result be a matrix transposed. If you try: apply(b, 2, function(y) sort(y, na.last=F)) The second parameter means scan column by column, and the result matrix will have the same dimension with origin.
On Tue, Jan 19, 2010 at 6:31 PM, Tal Galili <tal.gal...@gmail.com> wrote: > Hello Marco > > What I would do, is use "t" to transpose the matrix. > Why it is that apply switches the matrix, is beyond my knowledge - and I > would love to read more informed replies. > > Tal > > > > ----------------Contact > Details:------------------------------------------------------- > Contact me: tal.gal...@gmail.com | 972-52-7275845 > Read me: www.talgalili.com (Hebrew) | www.biostatistics.co.il (Hebrew) | > www.r-statistics.com/ (English) > ---------------------------------------------------------------------------------------------- > > > > > On Tue, Jan 19, 2010 at 12:27 PM, marco salvini > <marco.salv...@gmail.com>wrote: > >> Can you please help on the issue? >> I using the apply command on a matrix below the example: >> >> Create a vector >> x =c(5, 3, 2:4, NA, 7, 3, 9, 2, 1, 5) >> >> create a matrix of 2 rows by 6 columns >> b=matrix(x, 2,6) >> print(b) >> [,1] [,2] [,3] [,4] [,5] [,6] >> [1,] 5 2 4 7 9 1 >> [2,] 3 3 NA 3 2 5 >> >> using the command apply >> print(apply(b, 1, function(y) sort(y, na.last=F))) >> >> the output is a matrix of 6 rows by 2 columns. >> [,1] [,2] >> [1,] 1 NA >> [2,] 2 2 >> [3,] 4 3 >> [4,] 5 3 >> [5,] 7 3 >> [6,] 9 5 >> >> As you can see in the example I start with a matrix of (2 by 6) and the >> output of apply is a mtraxi of (6 by 2). >> This is very strange because I was expecting as output a matrix of the same >> dim (2 by 6) of the input matrix. I can solve this issues using an if >> statment on the dim of the matrix but if I am using a square matrix I am >> not >> able to control if the result of the apply is correct. >> >> Do anyone find a solution to this issue? >> thanks >> Marco >> >> [[alternative HTML version deleted]] >> >> ______________________________________________ >> R-help@r-project.org mailing list >> https://stat.ethz.ch/mailman/listinfo/r-help >> PLEASE do read the posting guide >> http://www.R-project.org/posting-guide.html >> and provide commented, minimal, self-contained, reproducible code. >> > > [[alternative HTML version deleted]] > > ______________________________________________ > R-help@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide http://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. > ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
