[R] column-wise deletion in data-frames

[Peter Dalgaard]

Chuck Cleland <ccleland at optonline.net> writes:

> > data <- as.data.frame(cbind(X1,X2,X3,X4,X5))
> > 
> > So only X1, X3 and X5 are vars without any NAs and there are some vars (X2 and
> > X4 stacked in between that have NAs). Now, how can I extract those former vars
> > in a new dataset or remove all those latter vars in between that have NAs
> > (without missing a single row)?
> > ...
> 
>    Someone else will probably suggest something more elegant, but how 
> about this:
> 
> newdata <- data[,-which(apply(data, 2, function(x){all(is.na(x))}))]

(I think that's supposed to be any(), not all(), and which() is
crossing the creek to fetch water.)

This should do it:

data[,apply(!is.na(data),2,all)]

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