I tried this - I get an empty set: <0 rows> (or 0-length row.names)
I guess this happens because the z variable takes only one value per row?? What works is: DFsub<-DF[DF$z == 1 | DF$z == 2,] but then, I do not eliminate the entries where there is only one entry for z given an a and c combination. Any idea what to do? -Ralph > Date: Wed, 13 Aug 2008 13:05:25 -0500 > From: [EMAIL PROTECTED] > Subject: RE: [R] subsetting matrix according to columns with character index > To: [EMAIL PROTECTED] > > it must be a dataframe so, if it was DF, then, assuming i understand > what you want then either of the following should work: > > DFsub<-DF[DF$z == 1 & DF$z == 2,] > > or > > DFsub<-subset(DF, z == 1 & z == 2 ) > > > On Wed, Aug 13, 2008 at 2:00 PM, Ralph S. wrote: > > > Hi, > > > > I have a long matrix of the following form which I would like to > > subset according to the third column: > > > > [x y z]: > > > > a1 c1 1 > > a1 c1 2 > > a2 c1 1 > > a1 c2 1 > > a1 c2 2 > > . . . > > > > > > The first two columns a characters ai and cj. > > > > I would like to keep all the rows where there are two entries for z, 1 > > and 2. > > > > That is, I want: > > a1 c1 1 > > a1 c1 2 > > a1 c2 1 > > a1 c2 2 > > . . . > > > > I try to use something like df[by(df,c(df$x,df$y),sum(z)==3),] but > > that only gives me one line of data per x y combination. > > > > Is there an easy way of coding to keep all rows for a and c > > combinations where z has entries both 1 and 2? > > Many thanks, > > > > Ralph > > > > _________________________________________________________________ > > > > > > LM_WLYIA_whichathlete_us > > ______________________________________________ > > R-help@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. _________________________________________________________________ [[alternative HTML version deleted]] ______________________________________________ R-help@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.
