[R] Issues with the way Apply handled NA's

S Ellison S.Ellison at LGCGroup.com
Wed Nov 16 15:57:59 CET 2016

> -----Original Message-----
> You can check for an empty vector as follows:
> ...
> vals <- apply(plabor[c("colA","colB","colC")],1,function(x) length(na.omit(x)))
> vals # [1] 3 0 3 2 
> <- ifelse(vals>0, plabor$colD, NA) 

A slightly more compact variant that avoids the intermediate 'vals' variable is to apply an anonymous function that does the check internally:

plabor$colD <- apply(plabor, 1, function(x) if(all(is.na(x))) NA else prod(x, na.rm=TRUE))

S Ellison

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