Format printing inside a matrix
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 <spurdle.a at 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
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