Wolski
2004-Sep-07 09:48 UTC
[Rd] package methods different behaviour R1.9.1 patched and R2.0.0
Hi! Concerning different behaviour between 1.9.1 patched and: R : Copyright 2004, The R Foundation for Statistical Computing Version 2.0.0 Under development (unstable) (2004-09-06), ISBN 3-900051-07-0 Subtitle: as(x,"vector"); x is of class "Massvector"; never enters setAs("Massvector","vector"... The same code: as(mvl[[1]],"vector") causes under R1.9.1 to enter the function setAs("Massvector","vector" ,function(from) ... This never happens under R2.0.0. The class "Massvector" contains class "Matrix" A phenomenological description of what happens instead with R2.0.0 is as(as(mvl[[1]],"Matrix"),"vector") and its not what I would expect. Is this an intended behaviour in R2.0.0? /E
Wolski
2004-Sep-07 10:29 UTC
[Rd] package methods different behaviour R1.9.1 patched and R2.0.0
I had a typo in the previous mail "Massvector" extends "matrix" not "Matrix" /E
John Chambers
2004-Sep-07 16:35 UTC
[Rd] package methods different behaviour R1.9.1 patched and R2.0.0
It's not possible to tell what you're expecting or actually seeing from this mail. We need to see your code and the results, not your interpretation of how as() is implemented. Meanwhile, here's how a simple class that extends "matrix" works in 2.0.0 With the code: setClass("mat1", representation(id="character"), contains = "matrix") mm <- matrix(1:12,3,4) mmm <- new("mat1", mm, id = "numeric") The result is: R> as(mmm, "vector") [1] 1 2 3 4 5 6 7 8 9 10 11 12 Class "vector" is one of the basic R classes; as explained in ?as, the methods for these use the exisiting as.<class> functions, as.vector in this case. The result is indeed the same as coercing mmm to "matrix" first and then to vector R> as(as(mmm, "matrix"), "vector") [1] 1 2 3 4 5 6 7 8 9 10 11 12 as one would expect, but the method for coercing class "mat1" does not go through "matrix": R> selectMethod("coerce", c("mat1", "vector")) function (from, to, strict = TRUE) { value <- as.vector(from) if (strict) attributes(value) <- NULL value } <environment: namespace:methods> Wolski wrote:> > Hi! > > Concerning different behaviour between 1.9.1 patched and: > R : Copyright 2004, The R Foundation for Statistical Computing > Version 2.0.0 Under development (unstable) (2004-09-06), ISBN 3-900051-07-0 > > Subtitle: > as(x,"vector"); x is of class "Massvector"; never enters setAs("Massvector","vector"... > > The same code: > > as(mvl[[1]],"vector") > causes under R1.9.1 to enter the function > setAs("Massvector","vector" > ,function(from) > ... > > This never happens under R2.0.0. > > The class "Massvector" contains class "Matrix" > > A phenomenological description of what happens instead with R2.0.0 is > > as(as(mvl[[1]],"Matrix"),"vector") > > and its not what I would expect. > > Is this an intended behaviour in R2.0.0? > > /E > > ______________________________________________ > R-devel@stat.math.ethz.ch mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel-- John M. Chambers Bell Labs, Lucent Technologies office: (908)582-2681 700 Mountain Avenue, Room 2C-282 fax: (908)582-3340 Murray Hill, NJ 07974