I've been reminded by Prof. Brian Ripley that R's
log() function will indeed handle zeros appropriately.
Apologies to S Ellison and Hadley Wickham.
Peter Ehlers
On 2011-01-17 06:55, Peter Ehlers wrote:
On 2011-01-17 02:19, S Ellison wrote:
Will this do?
x<- runif(20, 1, 100)
exp( median( log( x) ) )
S Ellison
That's what Hadley proposed, too. It's fine for
your example, but there is potentially a small
problem with this method: the data must be positive.
Since it's not unusual to see data with some zeros,
the log() would fail.
Depending on what type of data I was going to use
this modification of the median for, I would consider
modifying the (quite short) median.default function,
with appropriate additional data checks.
Peter Ehlers
Skull Crossbones<witch.of.agnessi at gmail.com> 15/01/2011 16:26>>>
Hi All,
I need to calculate the median for even number of data points.However
instead of calculating
the arithmetic mean of the two middle values,I need to calculate their
geometric mean.
Though I can code this in R, possibly in a few lines, but wondering if
there
is
already some built in function.
Can somebody give a hint?
Thanks in advance