Hi Michael, Thanks for your reply. I suppose using a new S3/S4 class wrapping the list could solve my problem, but again I think it brings too much cost for maintaining the expected behavior. I was aware that Rmpfr package takes this approach and uses a similar structure (a S4 class wrapping a list of S4 objects) to represent the matrix or higher-order array with arbitrary precision.
And yes S4Vectors was a great package -- one can easily extend a class defined in S4Vectors and get expected behavior. However, in my case I was hoping my particular data structure could play well with matrix, data frame, etc. Best regards, Jialin On Sunday, July 7, 2019 7:04:03 PM PDT Michael Lawrence wrote: > A generic for displaying an object in a cell would be a reasonable > solution for this particular problem. However, as soon as you start > treating these objects as data (like putting them into a matrix), > you're likely going to want vectorized operations over them, which > means formalized vector and matrix classes. S4Vectors in Bioconductor > facilitates this for vectors, but not for higher-order arrays. > > Michael > > On Sun, Jul 7, 2019 at 4:44 PM Abby Spurdle <spurdl...@gmail.com> wrote: > > > I am not sure if there is an existing solution to this, but I want my S4 > > > objects inside a list matrix showing correctly. > > > R> matrix(lst, 2) > > > > > > [,1] [,2] [,3] [,4] [,5] > > > > > > [1,] ? ? ? ? ? > > > [2,] ? ? ? ? ? > > > Is it possible that the print method for matrix can call some type of > > > > generic > > > > > such as `as.character` or `format` when it encounters such cases? > > > > I had some difficulty understanding this question. > > So, I'm going to paraphrase it. > > > > R, to the best of my knowledge, does not support object arrays, as such. > > (Or if it does, I've certainly missed the memo on this one). > > > > The closest option, is to create an (S3) list of (S3 or S4) objects. > > This is sufficient in the one-dimension case. > > However, to provide functionality of two- or three-dimensional object > > arrays, one can create a matrix (or array) from the list. > > > > It's desirable to print such matrices and arrays. > > This is possible but the output contains an array of question marks, which > > isn't helpful. > > > > Would it be possible for the print method for both matrices and arrays > > (conditional on having a list type), call the format method for each > > object, possibly creating a character matrix? > > Presumably there are other approaches, but the main thing is that the > > output is useful and it's easy for R users to control the way objects (in > > matrices and arrays) are printed. > > > > > Or is there any other place that I can override without introducing a > > > new > > > > S3 class? > > > > In theory, the simplest approach is to redefine the print method for > > matrices. > > However, that would be unacceptable in a CRAN package, probably... > > > > So, unless R Core change the print method, you may have to create a matrix > > subclass. > > > > > > Abs > > > > [[alternative HTML version deleted]] > > > > ______________________________________________ > > R-devel@r-project.org mailing list > > https://stat.ethz.ch/mailman/listinfo/r-devel ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
