cumulative geometric mean

[spsanderson]

Function:

#' Cumulative Geometric Mean
#' 
#' @family Vector Function
#' 
#' @author Steven P. Sanderson II, MPH
#' 
#' @details
#' A function to return the cumulative geometric mean of a vector.
#' `exp(cummean(log(.x)))`
#' 
#' @description 
#' A function to return the cumulative geometric mean of a vector.
#' 
#' @parm .x A numeric vector
#' 
#' @examples 
#' x <- mtcars$mpg
#' 
#' cgmean(x)
#' 
#' @return 
#' A numeric vector
#' 
#' @export
#' 

cgmean <- function(.x){
  exp(cummean(log(.x)))
}

Example:

> cgmean(x)
 [1] 21.00000 21.00000 21.58363 21.53757 20.93755 20.43547 19.41935 19.98155
 [9] 20.27666 20.16633 19.93880 19.61678 19.42805 19.09044 18.33287 17.69470
[17] 17.50275 18.11190 18.61236 19.17879 19.28342 19.09293 18.90457 18.62961
[25] 18.65210 18.92738 19.15126 19.46993 19.33021 19.34242 19.18443 19.25006