CVCL function

Confidence limits of a CV for log-normal data

The function calculates the confidence limits (either 1-sided or 2-sided) via the

distribution of the error variance the CV is based on. utf-8

CVCL(CV, df, side = c("upper", "lower", "2-sided"), alpha = 0.05)

Arguments

• CV: Coefficient of variation as ratio (not percent)
• df: degrees of freedom of the CV (error variance)
• side: Side(s) to calculate the confidence limits for, defaults to upper
• alpha: Type I error probability, aka significance level

Returns

Numeric vector of the confidence limits named as lower CL and upper CL.

In case of the one-sided upper confidence limit the lower CL is = 0.

In case of the one-sided lower confidence limit the upper CL is = Inf.

Author(s)

D. Labes

Examples

# upper one-sided 95% CL of a CV=0.3 
# from a study with df=22 (f.i. a 2x2 crossover with n=24)
# default side="upper" since not explicitly given
CVCL(0.3, df = 22)
# should give:
#  lower CL  upper CL 
# 0.0000000 0.4075525