I'm trying to create an extension to data.frame with more complex row and column names, and have run into some problems:> setClass("new-data.frame", representation("data.frame"))[1] "new-data.frame" Warning message: old-style ('S3') class "data.frame" supplied as a superclass of "new-data.frame", but no automatic conversion will be peformed for S3 classes in: .validDataPartClass(clDef, name) Do I need to be worried about this?> new("new-data.frame", data.frame())Error in initialize(value, ...) : initialize method returned an object of class "data.frame" instead of the required class "new-data.frame" I guess this is related to the warning above. I presume I can fix this with an initialize function, but I'm not sure how to go about referring to the data frame that is the object. Is there a way to extend a data.frame, or do I need to create an object that contains the data frame in a slot? Thanks for your help, Hadley
the help page on "setOldClass" might help you. In particular the section "Register or Convert?". Matthias hadley wickham schrieb:>I'm trying to create an extension to data.frame with more complex row >and column names, and have run into some problems: > > > >>setClass("new-data.frame", representation("data.frame")) >> >> >[1] "new-data.frame" >Warning message: >old-style ('S3') class "data.frame" supplied as a superclass of >"new-data.frame", but no automatic conversion will be peformed for S3 >classes in: .validDataPartClass(clDef, name) > >Do I need to be worried about this? > > > >>new("new-data.frame", data.frame()) >> >> >Error in initialize(value, ...) : initialize method returned an object >of class "data.frame" instead of the required class "new-data.frame" > >I guess this is related to the warning above. I presume I can fix >this with an initialize function, but I'm not sure how to go about >referring to the data frame that is the object. >Is there a way to extend a data.frame, or do I need to create an >object that contains the data frame in a slot? > >Thanks for your help, > >Hadley > >______________________________________________ >R-help at stat.math.ethz.ch mailing list >https://stat.ethz.ch/mailman/listinfo/r-help >PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html > >-- StaMatS - Statistik + Mathematik Service Dipl.Math.(Univ.) Matthias Kohl www.stamats.de