Extending each element in a list, or rbind()-ing arrays of different length without recycling

(typos corrected)

Combining the various approaches on the list, here's a simple
one-liner that puts the NAs at the end:

    t(apply(mat,1,function(r) { dr<-duplicated(r); c( r[!dr],
rep(NA,sum(dr)) ) }))

If you don't care where the NAs are, the following is a tad shorter
and perhaps clearer:

    mat[ t(apply(mat,1,duplicated)) ] <- NA                  # modifies mat

        -s

On Fri, Feb 13, 2009 at 12:49 PM, Stavros Macrakis

Combining the various approaches on the list, here's a simple
one-liner that puts the NAs at the end:

    t(apply(mat,1,function(r) { dr<-duplicated(r); c( r[!dr],
rep(NA,sum(dr)) ) ))

If you don't care where the NAs are, the following is a tad shorter
and perhaps clearer:

    mat[ t(apply(mat,1,duplicated)) ] < -NA                  # modifies mat

        -s