> with(dattrial, table(A_is_missing=is.na(a), Week))
Week
A_is_missing 3 4
FALSE 2 3
TRUE 1 0
> with(dattrial, table(A_is_missing=is.na(a), Week))["TRUE", ] # extract the
> missing="TRUE" row, note quotes
3 4
1 0
Bill Dunlap
Spotfire, TIBCO Software
wdunlap tibco.com
> -----Original Message-----
> From: r-help-boun...@r-project.org [mailto:r-help-boun...@r-project.org] On
> Behalf
> Of Tagmarie
> Sent: Monday, September 17, 2012 3:03 AM
> To: r-help@r-project.org
> Subject: [R] count NAs per week
>
> Even though I work with R since a year or so I still struggle with simple
> problems. I hope someone can help me with this. Been trying for days and am
> a little frustrated now.
>
> I have a data frame somewhat like the one bellow:
>
> dattrial<-data.frame(a=c(1,NA,rnorm(4,10)), Week=c(3,3,3,4,4,4))
>
> I want to know how many NAs I have in week 3 and in week 4.
>
>
>
> --
> View this message in context:
> http://r.789695.n4.nabble.com/count-NAs-per-week-
> tp4643351.html
> Sent from the R help mailing list archive at Nabble.com.
>
> ______________________________________________
> 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.
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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.
