[R] efficient is.na tabulation?

[Chuck Cleland]

On 2/25/2008 8:59 AM, Angelo Passalacqua wrote:
> I am aware of
> 
> table(is.na(df$var))
> 
> but is there an efficient way of create a table that shows the number of
> missing values in each variable of a data frame?
> 
> Right now I am forced to create a new variable, varna<-is.na(df$var), for
> each variable of the data frame, bind them to a new data frame and tabulate
> it, but surely there is a simpler way?
> 
> any help is greatly appreciated,
> angelo

   Are you looking for colSums(is.na(df)) or colMeans(is.na(df)) ?  The 
is.na function can be applied to whole data frames.

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Chuck Cleland, Ph.D.
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