Re: [R] empty array

2008-03-18 Thread Robin Hankin
Hello everyone I know other, more knowledgeable, people have replied to Christophe's question, but perhaps the List would be interested to know that zero-extent arrays are useful (to me at least) because although such an array has no content, the dimname are nevertheless retained: > a <- arr

Re: [R] empty array

2008-03-15 Thread Christophe Genolini
John Kane a écrit : > Will > mymatrix <- NULL do what you want? > Well, in your code, 'mymatrix' is not a matrix : a<-array(dim=c(0,0)) # Solution of Gabor Csardi <0 x 0 matrix> class(a) [1] "matrix" b<-NULL class(b) [1] "NULL" Your definition will probably works in most case, but in S4, the

Re: [R] empty array

2008-03-15 Thread John Kane
Will mymatrix <- NULL do what you want? --- Christophe Genolini <[EMAIL PROTECTED]> wrote: > Hi the list > > Is it possible to create an empty matrix ? I do not > mean an matrix with > a single value that is NA (which is not empty) but a > real empty one, > with length=0. > > I do not understa

Re: [R] empty array

2008-03-15 Thread Prof Brian Ripley
On Sat, 15 Mar 2008, Gabor Csardi wrote: > On Sat, Mar 15, 2008 at 04:33:32PM +0100, Christophe Genolini wrote: >> Hi the list >> >> Is it possible to create an empty matrix ? I do not mean an matrix with >> a single value that is NA (which is not empty) but a real empty one, >> with length=0. > >

Re: [R] empty array

2008-03-15 Thread Gabor Csardi
On Sat, Mar 15, 2008 at 04:33:32PM +0100, Christophe Genolini wrote: > Hi the list > > Is it possible to create an empty matrix ? I do not mean an matrix with > a single value that is NA (which is not empty) but a real empty one, > with length=0. Sure: > matrix(nrow=0, ncol=5) [,1] [,2] [

[R] empty array

2008-03-15 Thread Christophe Genolini
Hi the list Is it possible to create an empty matrix ? I do not mean an matrix with a single value that is NA (which is not empty) but a real empty one, with length=0. I do not understand why we have length(numeric()), length(factor()) and length(character()) to zero, and length(array()) to on