[R] Finding NAs in DF

[Ivan Calandra]

Maybe something along the lines:
apply(df,1, FUN=function(x) which(is.na(x)))

It's not exactly what you want, but it might work combined with the 
other solutions

HTH,
Ivan

Le 1/17/2011 12:23, Johannes Graumann a écrit :
> Both versions do not do what I am looking for, as they do not differentiate
> where the NA is, if there is just one.
> My original wished for result therefore holts, but should probably be
> rewritten
> 	c(NA,"B","AB","A")
>
> Joh
>
> On Monday 17 January 2011 14:06:30 Patrick Burns wrote:
>> Simpler would be:
>>
>> rowSums(is.na(df))
>>
>> On 17/01/2011 10:13, Ivan Calandra wrote:
>>> Hi,
>>>
>>> I hope you made a mistake in c(NA,"TWO","BOTH","ONE") because if not, I
>>> have no idea what you're looking for...
>>>
>>> But would that do?
>>> df<- data.frame(A=c(1,2,NA,NA),B=c(1,NA,NA,4))
>>> apply(df,1, FUN=function(x) length(x[is.na(x)]))
>>> [1] 0 1 2 1
>>>
>>> There might be better ways to do it, but it works
>>> HTH,
>>> Ivan
>>>
>>> Le 1/17/2011 11:01, Johannes Graumann a écrit :
>>>> Hi,
>>>>
>>>> What is an efficient way to take this DF
>>>>
>>>> data.frame(A=c(1,2,NA,NA),B=c(1,NA,NA,4))
>>>>
>>>> and get
>>>> c(NA,"TWO","BOTH","ONE")
>>>>
>>>> as the result, where NA corresponds to a row without "NA"s, TWO
>>>> indicates NA
>>>> in the second and ONE in the first column.
>>>>
>>>> Thanks for any pointers.
>>>>
>>>> Joh
>>>>
>>>> ______________________________________________
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>>>> PLEASE do read the posting guide
>>>> http://www.R-project.org/posting-guide.html
>>>> and provide commented, minimal, self-contained, reproducible code.
>>>>
>>>>
>>>> ______________________________________________
>>>> 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.

-- 
Ivan CALANDRA
PhD Student
University of Hamburg
Biozentrum Grindel und Zoologisches Museum
Abt. Säugetiere
Martin-Luther-King-Platz 3
D-20146 Hamburg, GERMANY
+49(0)40 42838 6231
ivan.calandra at uni-hamburg.de

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