From: Dimitris Rizopoulos <dimitris.rizopoulos_at_med.kuleuven.ac.be>

Date: Tue 03 May 2005 - 01:13:32 EST

Dimitris Rizopoulos

Ph.D. Student

Biostatistical Centre

School of Public Health

Catholic University of Leuven

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 Received on Tue May 03 01:36:03 2005

Date: Tue 03 May 2005 - 01:13:32 EST

you could try something like this:

dat <- rbind(c(1, 2, 5, 2, 3, NA, 5, NA, 1, 4),

c(3, 1, 4, 5, 2, 6, NA, 4, NA, 1))
##########

# (1)

rowSums(is.na(dat[, 6:10]))

## (2)

dat. <- dat[, 1:5]

dat.[is.na(dat[, 6:10])] <- NA

rowSums(dat., na.rm=TRUE)

rowMeans(dat., na.rm=TRUE)

I hope it helps.

Best,

Dimitris

Dimitris Rizopoulos

Ph.D. Student

Biostatistical Centre

School of Public Health

Catholic University of Leuven

Address: Kapucijnenvoer 35, Leuven, Belgium

Tel: +32/16/336899 Fax: +32/16/337015 Web: http://www.med.kuleuven.ac.be/biostat/ http://www.student.kuleuven.ac.be/~m0390867/dimitris.htm

- Original Message ----- From: "Christoph Scherber" <Christoph.Scherber@uni-jena.de> To: <r-help@stat.math.ethz.ch> Sent: Monday, May 02, 2005 4:52 PM Subject: [R] "apply" question

> Dear R users,

*>
**> Iīve got a simple question but somehow I canīt find the solution:
**>
**> I have a data frame with columns 1-5 containing one set of integer
**> values, and columns 6-10 containing another set of integer values.
**> Columns 6-10 contain NAīs at some places.
**>
**> I now want to calculate
**> (1) the number of values in each row of columns 6-10 that were NAīs
**> (2) the sum of all values on columns 1-5 for which there were no
**> missing values in the corresponding cells of columns 6-10.
**>
**>
**> Example: (letīs call the data frame "data")
**>
**> Col1 Col2 Col3 Col4 Col5 Col6 Col7 Col8 Col9 Col10
**> 1 2 5 2 3 NA 5 NA 1 4
**> 3 1 4 5 2 6 NA 4 NA 1
**>
**> The result would then be (for the first row)
**> (1) "There were 2 NAīs in columns 6-10."
**> (2) The mean of Columns 1-5 was 2+2+3=7" (because there were NAīs in
**> the 1st and 3rd position in rows 6-10)
**>
**> So far, I know how to calculate the rowSums for the data.frame, but
**> I donīt know how to condition these on the values of columns 6-10
**>
**> rowSums(data[,1:5]) #thatīs straightforward
**> apply(data[,6:19],1,function(x)sum(is.na(x))) #this also works fine
**>
**> But I donīt know how to select just the desired values of columns
**> 1-5 (as described above)
**>
**>
**> Can anyone help me? Thanks a lot in advance!
**>
**> Best regards
**> Christoph
**>
**> ______________________________________________
**> 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
**>
*

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 Received on Tue May 03 01:36:03 2005

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