Calculate the mean and 95% confidence interval of a sample of numbers under a transform

sample.mean.CI.transform <- function(x, transform.func = identity, anti.transform.func = identity)
{
    ## Purpose: 
    ##   Calculate the mean and 95% CI of a sample of numbers under a transform. 
    ## 
    ## Author: Feiming Chen
    ## 
    ## Arguments: 
    ##   - x : a vector of positive numerical values
    ##   - transform.func: a function for transforming the original values to a new scale.
    ##   - anti.transform.func: a function for back-transforming the values to the original scale.
    ## 
    ## Return: 
    ##   - m : mean based on a particular transform function. 
    ## 
    ## ________________________________________________

    y <- transform.func(x)              # transform to a new scale
    a <- t.test(y)                      # estimate the mean and 95% CI based on t-distribution
    c(anti.transform.func(a$estimate), CI = anti.transform.func(a$conf.int))
}
if (F) {                                # Unit Test
    x <- exp(1:10)
    sample.mean.CI.transform(x)             # no transform
    ## estimate the mean under the log-normal distributional assumption
    sample.mean.CI.transform(x, transform.func = log, anti.transform.func = exp) 
}