I did specify only the three columns of interest
c('bd.n','ht.n','dbh.n')
as the second (column) index, and I did superficially check the results
which turned out as I had hoped. Only the three columns listed were
changed and existing values _in_ those columns were retained.
So, I appear to be on my way again.Thanx again, DaveT. ************************************* >-----Original Message----- >From: jim holtman [mailto:[EMAIL PROTECTED] >Sent: November 20, 2007 04:21 PM >To: Thompson, David (MNR) >Cc: r-help@r-project.org >Subject: Re: [R] Process multiple columns of data.frame > >The problem with that solution is that if any of the columns in a row >has an NA in it, then all the columns of that row will be set to zero. > Is the what you want, or do you only want the specific entries set to >0? > >On Nov 20, 2007 4:07 PM, Thompson, David (MNR) ><[EMAIL PROTECTED]> wrote: >> Jim, >> >> What I'm getting at is my lack of understanding when manipulating >> data frame indices. I have tried something like your matrix example >> with variants of: Bout[ >is.na(Bout[,c('bd.n','ht.n','dbh.n')]), ] <- 0 >> >> only to receive the following error message: >> Error in `[<-.data.frame`(`*tmp*`, is.na(Bout[, c("bd.n", "ht.n", >> "dbh.n")]), : >> non-existent rows not allowed >> >> My questions were not focussed on the assignment value but, >> on the selection of multiple columns (of a single type) to process. >> Which is what I meant by concisely. >> >> And, lo and behold, in my attempts to reframe my questions I >(finally) >> came upon a solution: >> Bout[is.na(Bout$bd.n) | is.na(Bout$ht.n) | is.na(Bout$dbh.n), >> c('bd.n','ht.n','dbh.n')] <- 0 >> >> Thank you for your time, DaveT. >> ************************************* >> >> >-----Original Message----- >> >From: jim holtman [mailto:[EMAIL PROTECTED] >> >Sent: November 20, 2007 02:25 PM >> >To: Thompson, David (MNR) >> >Cc: r-help@r-project.org >> >Subject: Re: [R] Process multiple columns of data.frame >> > >> >It really depends on what you want to set the values that >contain NAs >> >to for the various type of the columns. Do you always want numerics >> >=0, characters ="", and factors =whatever? Do you want to >do this for >> >all the columns in a dataframe? If you want to it for all >the columns >> >in a matrix, it is easy, since all are the same type, and you are >> >setting them to zero (e.g., yourMatrix[is.na(yourMatrix)] <- 0). >> > >> >You can always write a function that can take in the names of the >> >columns and then depending on their types set the corresponding >> >values. So it depends on what you mean by "concisely" and how often >> >you want to do it. >> > >> >On Nov 20, 2007 12:27 PM, Thompson, David (MNR) >> ><[EMAIL PROTECTED]> wrote: >> >> Hello, >> >> >> >> How do I do the following more concisely? >> >> Bout[is.na(Bout$bd.n), 'bd.n'] <- 0 >> >> Bout[is.na(Bout$ht.n), 'ht.n'] <- 0 >> >> Bout[is.na(Bout$dbh.n), 'dbh.n'] <- 0 >> >> >> >> Would the form of such a command be different >> >> between numeric, character and factor columns? >> >> >> >> . . . between data.frames and matrices? >> >> >> >> Thanx, DaveT. >> >> ************************************* >> >> Silviculture Data Analyst >> >> Ontario Forest Research Institute >> >> Ontario Ministry of Natural Resources >> >> [EMAIL PROTECTED] >> >> http://ofri.mnr.gov.on.ca >> >> >> >> ______________________________________________ >> >> 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. >> >> >> > >> > >> > >> >-- >> >Jim Holtman >> >Cincinnati, OH >> >+1 513 646 9390 >> > >> >What is the problem you are trying to solve? >> > >> > > > >-- >Jim Holtman >Cincinnati, OH >+1 513 646 9390 > >What is the problem you are trying to solve? > ______________________________________________ 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.
