There is a maintainer for this contributed package... However, a zero column vector _is_ numeric(0) -- with dimension attributes c(3,0).
structure(numeric(0),dim=c(3,0)) c(Null(diag(3))) I.e., the ambiguity is pretty slight. Presumably, the help file wording goes back to S-PLUS which (to my recollection) didn't allow zero-extent matrices. The actual behaviour is a clear improvement. - Peter D. On 10 Nov 2014, at 13:49 , Georgi Boshnakov <georgi.boshna...@manchester.ac.uk> wrote: > Hi, > > Function Null from package MASS seems to return a matrix with zero columns > and the expected number of rows when > the null space of the argument contains only the zero vector, e.g. > >> library(MASS) >> diag(nrow=3) > [,1] [,2] [,3] > [1,] 1 0 0 > [2,] 0 1 0 > [3,] 0 0 1 > >> Null(diag(nrow=3)) > > [1,] > [2,] > [3,] > > But the documentation of Null seems to imply that the result is numeric(0): > > ----------------------------------------------- > > Value: > > The matrix 'N' with the basis for the null space, or an empty > vector if the matrix 'M' is square and of maximal rank. > > ----------------------------------------------- > > (R version 3.1.1 Patched (2014-09-21 r66653) -- "Sock it to Me") > > Georgi > > ______________________________________________ > R-devel@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 Email: pd....@cbs.dk Priv: pda...@gmail.com ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
