[R] Process multiple columns of data.frame

[jim holtman]

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)
<David.John.Thompson at ontario.ca> 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$dbh.n),
> c('bd.n','ht.n','dbh.n')] <- 0
>
> Thank you for your time, DaveT.
> *************************************
>
> >-----Original Message-----
> >From: jim holtman [mailto:jholtman at gmail.com]
> >Sent: November 20, 2007 02:25 PM
> >To: Thompson, David (MNR)
> >Cc: r-help at r-project.org
> >Subject: Re: [R] Process multiple columns of data.frame
> >
> >It really depends on what you want to set the values that contain NAs
> >to for the various type of the columns.  Do you always want numerics
> >=0, characters ="", and factors =whatever?  Do you want to do this for
> >all the columns in a dataframe?  If you want to it for all the columns
> >in a matrix, it is easy, since all are the same type, and you are
> >setting them to zero (e.g., yourMatrix[is.na(yourMatrix)] <- 0).
> >
> >You can always write a function that can take in the names of the
> >columns and then depending on their types set the corresponding
> >values.  So it depends on what you mean by "concisely" and how often
> >you want to do it.
> >
> >On Nov 20, 2007 12:27 PM, Thompson, David (MNR)
> ><David.John.Thompson at ontario.ca> wrote:
> >> Hello,
> >>
> >> How do I do the following more concisely?
> >>        Bout[is.na(Bout$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
> >> david.john.thompson at ontario.ca
> >> http://ofri.mnr.gov.on.ca
> >>
> >> ______________________________________________
> >> R-help at 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?