On Thu, 28 Sep 2006, Joe W. Byers wrote: > Berton Gunter wrote: >> Please folks -- use indexing. >> >> myframe<-myframe[,c(1,5,2,3,4)] >> >> Which begs the question: why bother rearranging the columns anyway, since >> one can get them used, printed, etc. in any order you wish anytime you want >> just by specifying the indices in the order you want them. I suspect the >> question was motivated by too much Sas- or Excel -ism.
> Many of the time series classes expect a date in the first column of the > matrix or data.frame when creating the date-time object. Retrieving > data in a SQL query from a dB returns a character representation of the > date that requires conversion to a date. Performing this conversion is > easy but inserting this converted date column is not straight forward. Well-written R <--> DBMS software does return a date or date-time, and if it is the first column retrieved by other software, you want to _replace_ the _first_ column, not really relevant to the topic of your subject line. (Doing that is basic data manipulation, covered in Chapter 2 of MASS4, for example.) The initial assertion is not (necessarily) true of "ts" or "irts" or "its" or "zoo", so quite a few time-series class generators expect a date or date-time to be specified separately. >>> -----Original Message----- >>> From: [EMAIL PROTECTED] >>> [mailto:[EMAIL PROTECTED] On Behalf Of Timothy Bates >>> Sent: Wednesday, September 13, 2006 3:05 PM >>> To: Jon Minton; r-help@stat.math.ethz.ch >>> Subject: Re: [R] inserting columns in the middle of a dataframe >>> >>> >>>> Is there a built-in and simple way to insert new columns in >>> a dataframe? >>> >>> You do this by collecting the columns in the new order you desire, and >>> making a new frame. >>> >>> oldframe <- data.frame(matrix(0:14,ncol=3)) >>> newcol <- data.frame(20:24) >>> names(newcol) <- "newcol" >>> newframe <- data.frame(c(oldframe[1],newcol, oldframe[2:3])) -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ R-help@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 and provide commented, minimal, self-contained, reproducible code.