Hi all I was wondering whether there has ever been an update on the rownames and colnames behaviour as described by Eric below?
I still get the same behaviour, exactly as described by Eric, on my WinXP installation of R-2.3.0. I also posted a message to r-help on Friday but looking through the online archives it seems to have not made it to the list. I would agree with Eric that a consistent use of the typecast would be a reasonable solution. Any comments? Tobias Brandt Quantitative Analyst Taquanta Asset Managers Nedbank Clock Tower Victoria & Alfred Waterfront, Cape Town 8001 Tel : +27 (0) 21 416 6602 Fax : +27 (0) 21 416 9945 Email : [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> >-----Original Message----- >From: [EMAIL PROTECTED] >[mailto:[EMAIL PROTECTED] On Behalf Of Erich Neuwirth >Sent: 21 March 2006 01:31 PM >To: [email protected] >Cc: Christian Prinoth >Subject: [R] rownames, colnames, and date and time > >I noticed something surprising (in R 2.2.1 on WinXP) According >to the documentation, rownames and colnames are character vectors. >Assigning a vector of class POSIXct or POSIXlt as rownames or >colnames therefore is not strictly according to the rules. >In some cases, R performs a reasonable typecast, but in some >other cases where the same typecast also would be possible, it >does not. > >Assigning a vector of class POSIXct to the rownames or names >of a dataframe creates a reasonable string representation of >the dates (and possibly times). >Assigning such a vector to the rownames or colnames of a >matrix produces rownames or colnames consisting of the integer >representation of the date-time value. >Trying to assign a vector of class POSIXlt in all cases >(dataframes and matrices, rownames, colnames, names) produces an error. > >Demonstration code is given below. > >This is somewhat inconsistent. >Perhaps a reasonable solution could be that the typecast used >for POSIXct and dataframes is used in all the other cases also. > >Code: > >mymat<-matrix(1:4,nrow=2,ncol=2) >mydf<-data.frame(mymat) >mydates<-as.POSIXct(c("2001-1-24","2005-12-25")) > >rownames(mydf)<-mydates >names(mydf)<-mydates >rownames(mymat)<-mydates >colnames(mymat)<-mydates > >print(deparse(mydates)) >print(deparse(rownames(mydf))) >print(deparse(names(mydf))) >print(deparse(rownames(mymat))) >print(deparse(colnames(mymat))) > >mydates1<-as.POSIXlt(mydates) > ># the following lines will not work and ># produce errors > >rownames(mydf)<-mydates1 >names(mydf)<-mydates1 >rownames(mymat)<-mydates1 >colnames(mymat)<-mydates1 > > >-- >Erich Neuwirth >Institute for Scientific Computing and >Didactic Center for Computer Science >University of Vienna >phone: +43-1-4277-39464 fax: +43-1-4277-39459 > >______________________________________________ >[email protected] mailing list >https://stat.ethz.ch/mailman/listinfo/r-help >PLEASE do read the posting guide! >http://www.R-project.org/posting-guide.html > ******************** Nedbank Limited Reg No 1951/000009/06. The following link displays the names of the Nedbank Board of Directors and Company Secretary. [ http://www.nedbank.co.za/terms/DirectorsNedbank.htm ] This email is confidential and is intended for the addressee only. The following link will take you to Nedbank's legal notice. [ http://www.nedbank.co.za/terms/EmailDisclaimer.htm ] ******************** [[alternative HTML version deleted]] ______________________________________________ [email protected] mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide! http://www.R-project.org/posting-guide.html
