asymptotic_test2 {cvequality}

Asymptotic test for the equality of coefficients of variation from k populations, using summary statistics when raw measurement data are not available.

Description

Test for k samples (k sample populations with unequal sized) from Feltz CJ, Miller GE (1996) An asymptotic test for the equality of coefficients of variation from k population. Stat Med 15:647–658

Usage

asymptotic_test2(k, n, s, x, seed)

Arguments

k

a numeric vector the number of groups

n

a numeric vector the numer of measurements in each group

s

a numeric vector the standard deviation of each group

x

a numeric vector the mean of each group

seed

optional, an integer that is the starting point used in the generation of a sequence of random numbers. Include a seed if you want reproducible output.

Value

a list with the test statistic and p-value

Examples

# Summary stats from Feltz and Miller 1996

miller <- data.frame(test = c('ELISA', 'WEHI', '`Viral inhibition`'),
                    Mean = c(6.8, 8.5, 6.0),
                    CV =   c(0.090, 0.462, 0.340),
                    N =    c(5, 5, 5))
# compute SD from mean and cv
miller$SD <- with(miller, CV * Mean)

 asymptotic_test2(k = nrow(miller), n = miller$N, s = miller$SD, x = miller$Mean)