From: Liaw, Andy <andy_liaw_at_merck.com>

Date: Tue 03 May 2005 - 01:06:47 EST

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 01:27:28 2005

Date: Tue 03 May 2005 - 01:06:47 EST

Try:

*> ## Number of NAs in columns 6-10.
**> colSums(is.na(data[6:10]))
*

Col6 Col7 Col8 Col9 Col10

1 1 1 1 0

*>
**> ## Number of NAs in each row of columns 6-10.
**> rowSums(is.na(data[6:10]))
*

1 2

2 2

*>
**> ## Sums of rows 1-5 omitting corresponding NAs in cols 6-10.
**> rowSums(data[,1:5] * !is.na(data[,6:10]))
*

1 2

7 9

If all entries are numeric, it'd be easier to use matrices instead of data frames.

**HTH,
**

Andy

*> From: Christoph Scherber
**>
*

> 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
**>
**> ______________________________________________
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**> 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 01:27:28 2005

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