If you only want a subset, then use that in the function:
Dataset.target <- apply(x,1,function(.row) sum(is.na(.row[3:8])))
This will put it back in column1:
> x <- matrix(1,10,10)
> x[sample(1:100,10)] <- NA
> x[,1] <- 0 # make sure column 1 has no NAs so sums are correct
> x
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
[1,] 0 1 NA 1 1 1 1 NA 1 1
[2,] 0 1 1 1 1 1 1 1 1 1
[3,] 0 1 1 1 1 1 1 1 1 NA
[4,] 0 1 1 1 1 1 1 NA 1 1
[5,] 0 1 1 NA 1 1 1 1 1 1
[6,] 0 1 1 1 1 1 1 1 1 1
[7,] 0 1 1 1 1 1 1 1 1 1
[8,] 0 NA 1 NA NA 1 NA 1 1 NA
[9,] 0 1 1 1 1 1 1 1 1 1
[10,] 0 1 1 1 1 1 1 1 1 1
> # get the sums of NA in 3:8 and put in column 1
> x[,1] <- apply(x, 1, function(.row) sum(is.na(.row[3:8])))
>
>
> x
[,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
[1,] 2 1 NA 1 1 1 1 NA 1 1
[2,] 0 1 1 1 1 1 1 1 1 1
[3,] 0 1 1 1 1 1 1 1 1 NA
[4,] 1 1 1 1 1 1 1 NA 1 1
[5,] 1 1 1 NA 1 1 1 1 1 1
[6,] 0 1 1 1 1 1 1 1 1 1
[7,] 0 1 1 1 1 1 1 1 1 1
[8,] 3 NA 1 NA NA 1 NA 1 1 NA
[9,] 0 1 1 1 1 1 1 1 1 1
[10,] 0 1 1 1 1 1 1 1 1 1
>
On Jan 21, 2008 8:47 PM, Jon Erik Ween <[EMAIL PROTECTED]> wrote:
> Thanks Jim
>
> I see how this works. Problem is, I need to interrogate only a subset
> of fields. In your example, I need to put the total number of "NA"
> fields out of fields 3..8, excluding 1,2 9 10. Also, I don't see how
> the method inserts the sum into a particular field in a row. I guess
> you could do
>
> Dataset.target <- apply(x,1,function(.row) sum(is.na(.row)))
>
> Thanks
>
> Jon
>
>
> Soli Deo Gloria
>
> Jon Erik Ween, MD, MS
> Scientist, Kunin-Lunenfeld Applied Research Unit
> Director, Stroke Clinic, Brain Health Clinic
> Baycrest Centre for Geriatric Care
> Assistant Professor, Dept. of Medicine, Div. of Neurology
> University of Toronto Faculty of Medicine
>
> Posluns Building, 6th Floor, Room 644
> Baycrest Centre for Geriatric Care
> 3560 Bathurst Street
> Toronto, Ontario M6A 2E1
> Canada
>
> Phone: 416-785-2500 x3636
> Fax: 416-785-2484
> Email: [EMAIL PROTECTED]
>
>
> Confidential: This communication and any attachment(s) may contain
> confidential or privileged information and is intended solely for the
> address(es) or the entity representing the recipient(s). If you have
> received this information in error, you are hereby advised to destroy
> the document and any attachment(s), make no copies of same and inform
> the sender immediately of the error. Any unauthorized use or
> disclosure of this information is strictly prohibited.
>
>
>
> On 21-Jan-08, at 8:28 PM, jim holtman wrote:
>
> > You need to do 'is.na(x)' instead of "x == NA".. Here is a way of
> > doing it:
> >
> >> x <- matrix(1,10,10)
> >> x[sample(1:100,10)] <- NA
> >> x
> > [,1] [,2] [,3] [,4] [,5] [,6] [,7] [,8] [,9] [,10]
> > [1,] 1 1 1 1 1 1 1 1 1 1
> > [2,] 1 1 1 1 1 1 NA 1 1 1
> > [3,] 1 1 1 1 1 1 1 1 1 1
> > [4,] 1 1 1 1 1 1 1 1 1 1
> > [5,] 1 1 1 1 1 1 1 1 1 1
> > [6,] NA 1 1 1 1 1 1 1 NA 1
> > [7,] 1 1 NA NA 1 NA 1 1 1 NA
> > [8,] 1 1 1 1 1 NA 1 1 1 1
> > [9,] 1 1 1 1 1 1 1 1 NA 1
> > [10,] 1 NA 1 1 1 1 1 1 1 1
> >>
> >> apply(x,1,function(.row) sum(is.na(.row)))
> > [1] 0 1 0 0 0 2 4 1 1 1
> >>
> >
> >
> > On Jan 21, 2008 7:23 PM, Jon Erik Ween <[EMAIL PROTECTED]>
> > wrote:
> >> Hi!
> >>
> >> I need to conditionally update a dataframe field based on values in
> >> other fields and can't find even how to search for this right. Sorry
> >> if this has been asked before.
> >>
> >> But, specifically, I have a 490 X 221 dataframe and need to count, by
> >> row, how many fields in Dataframe$field_a...Dataframe$field_zz are
> >> non-null and enter this value in Dataset$ABCtaskNum. I have field
> >> name definitions in a vector "vars" and tried writing a custom
> >> function to handle the within-row calculation
> >>
> >> myfunct <-function () {for (i in 1:length(vars)) {if (vars[i] != NA)
> >> {Dataset$ABCtaskNum<-Dataset$ABCtaskNum+1}}}
> >>
> >> and then use "apply" to handle the row to row calculation
> >>
> >> Dataset <- apply(Dataset, 1, myfunc) Where Dataset already has field
> >> Dataset$ABCtaskNum set to 0 in all rows.
> >>
> >> But that didn't work. Doesn't help if I declare variables (vars and
> >> ABCtaskNum) in the function declaration either, but then I haven't
> >> quite figured out how best to do variable substitutions in R.
> >>
> >> Thanks for any help. Cheers
> >>
> >> Jon
> >>
> >> Soli Deo Gloria
> >>
> >> Jon Erik Ween, MD, MS
> >> Scientist, Kunin-Lunenfeld Applied Research Unit
> >> Director, Stroke Clinic, Brain Health Clinic
> >> Baycrest Centre for Geriatric Care
> >> Assistant Professor, Dept. of Medicine, Div. of Neurology
> >> University of Toronto Faculty of Medicine
> >>
> >> Posluns Building, 6th Floor, Room 644
> >> Baycrest Centre for Geriatric Care
> >> 3560 Bathurst Street
> >> Toronto, Ontario M6A 2E1
> >> Canada
> >>
> >> Phone: 416-785-2500 x3636
> >> Fax: 416-785-2484
> >> Email: [EMAIL PROTECTED]
> >>
> >>
> >> Confidential: This communication and any attachment(s) may contain
> >> confidential or privileged information and is intended solely for the
> >> address(es) or the entity representing the recipient(s). If you have
> >> received this information in error, you are hereby advised to destroy
> >> the document and any attachment(s), make no copies of same and inform
> >> the sender immediately of the error. Any unauthorized use or
> >> disclosure of this information is strictly prohibited.
> >>
> >>
> >>
> >> [[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.
> >>
> >
> >
> >
> > --
> > 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.
>
--
Jim Holtman
Cincinnati, OH
+1 513 646 9390
What is the problem you are trying to solve?
______________________________________________
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