[R] attr.all.equal() and all.equal(attributes(), attributes())

[Heinz Tuechler]

At 14:24 09.11.2008, Peter Dalgaard wrote:
>Heinz Tuechler wrote:
>>Dear All!
>>If I try to compare the attributes of two 
>>objects, I find a surprising behaviour of 
>>attr.all.equal(). With identical attributes I 
>>receive the answert NULL. If the attributes 
>>differ, the answer is as expecxted and differences are shown.
>>all.equal(attributes(), attributes()) instead 
>>returns TRUE, if attributes are equal.
>
>That _is_ as documented,  although if you want 
>to quibble, it should probably also have been mentioned in the Value section.

Sorry, I admit that I read only the value section.
Heinz



>I don't know if there's a a rationale for it. The actual code goes
>
>msg <- NULL
>if (....) msg <- c(msg, some text)
>if (.....
>msg
>
>so it returns NULL if none of the ifs are taken, 
>but it could easily be changed to return
>
>if (is.null(msg)) TRUE else msg
>
>("easily" depending, of course, on how much code 
>actually depends on the current behaviour...)
>
>>See example:
>>v <- 1:5
>>attr(v, 'testattribute') <- 'testattribute v'
>>v_c <- v
>>attributes(v)
>>$testattribute
>>[1] "testattribute v"
>>attributes(v_c)
>>$testattribute
>>[1] "testattribute v"
>>all.equal(v, v_c)
>>[1] TRUE
>>attr.all.equal(v, v_c)
>>NULL  << - - - - - - - - - - here is, what I don't expected
>>all.equal(attributes(v), attributes(v_c))
>>[1] TRUE
>>attr(v_c, 'testattribute') <- 'testattribute v_c'
>>attr.all.equal(v, v_c)
>>[1] "Attributes: < Component 1: 1 string mismatch >"
>>all.equal(attributes(v), attributes(v_c))
>>[1] "Component 1: 1 string mismatch"
>>Thanks for your attention
>>Heinz Tüchler
>>Version:
>>  platform = i386-pc-mingw32
>>  arch = i386
>>  os = mingw32
>>  system = i386, mingw32
>>  status = Patched
>>  major = 2
>>  minor = 8.0
>>  year = 2008
>>  month = 11
>>  day = 04
>>  svn rev = 46830
>>  language = R
>>  version.string = R version 2.8.0 Patched (2008-11-04 r46830)
>>Windows XP (build 2600) Service Pack 2
>>Locale:
>>LC_COLLATE=German_Austria.1252;LC_CTYPE=German_Austria.1252;LC_MONETARY=German_Austria.1252;LC_NUMERIC=C;LC_TIME=German_Austria.1252 
>>
>>Search Path:
>>  .GlobalEnv, package:stats, package:graphics, 
>> package:grDevices, package:utils, 
>> package:datasets, package:methods, Autoloads, package:base
>>______________________________________________
>>R-help at r-project.org mailing list
>>https://stat.ethz.ch/mailman/listinfo/r-help
>>PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
>>and provide commented, minimal, self-contained, reproducible code.
>
>
>--
>    O__  ---- Peter Dalgaard             Øster Farimagsgade 5, Entr.B
>   c/ /'_ --- Dept. of Biostatistics     PO Box 2099, 1014 Cph. K
>  (*) \(*) -- University of Copenhagen   Denmark      Ph:  (+45) 35327918
>~~~~~~~~~~ - (p.dalgaard at biostat.ku.dk)              FAX: (+45) 35327907