Hi,

I am trying to modify my code which currently uses standard 2-D R matrices,
so that it can use ff (file-based) matrices instead. After pouring through
the documentation, I am still having a hard time understanding how to (or if
it is possible to) index my ff's using logical matrices. For example,
without bringing the entire matrix back into memory via 'm[,]', how would I
do the equivalent of any of these (where 'm' and 'm2' are 'ff's of the same
dimension):

m[ m > 5 ] <- NA

or

tmp.vec <- m[ m2 == 1 ]

or

inds <- which( m2 == 1 )

??

Thanks in advance for any insights.
-David




-- 
*David J Reiss, PhD <http://baliga.systemsbiology.net/drupal/users/dreiss>*
Senior Research Scientist, Computational Biology, Baliga
Lab<http://baliga.systemsbiology.net/>
Institute for Systems Biology <http://www.systemsbiology.org>
1441 N 34th St., Seattle, WA  98103 (USA)

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