[R] Geometric mean of rows in matrix
David Winsemius
dwinsemius at comcast.net
Thu Aug 20 20:45:30 CEST 2009
On Aug 20, 2009, at 2:22 PM, Edward Chen wrote:
> Is there a function or an easier way to computer geometric means of
> each
> rows in a nxn matrix and spit out in an 1xn matrix ?
> xx <- matrix(10+rnorm(100), 10)
> apply(xx, 1, function(x) exp(mean(log(x))) )
[1] 10.084711 10.034054 9.622909 9.780703 10.085467 9.800346
10.283556 9.666453 9.802996
[10] 9.917821
This of course will return NaN if there are any negative values. There
are also several implementations of geometric mean functions that can
be found with the obvious search strategy at:
http://search.r-project.org/nmz.html
--
David Winsemius, MD
Heritage Laboratories
West Hartford, CT
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