median by geometric mean
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