LRTesteR (version 1.3.1)

gamma_shape_one_way: Test the equality of shape parameters of gamma distributions.

Description

Test the equality of shape parameters of gamma distributions.

Usage

gamma_shape_one_way(x, fctr, conf.level = 0.95)

Value

An S3 class containing the test statistic, p value, list of likelihood based confidence intervals, overall confidence level, individual confidence level of each interval and alternative hypothesis.

Arguments

x

a numeric vector of data.

fctr

a factor vector indicating groups.

conf.level

overall confidence level of the likelihood intervals. Uses Bonferroni correction.

Details

• Null: All shapes are equal. (shape_1 = shape_2 ... shape_k).

• Alternative: At least one shape is not equal.

Examples

library(LRTesteR)

# Null is true
set.seed(1)
x <- rgamma(150, 2, 2)
fctr <- c(rep(1, 50), rep(2, 50), rep(3, 50))
fctr <- factor(fctr, levels = c("1", "2", "3"))
gamma_shape_one_way(x, fctr, .95)

# Null is false
set.seed(1)
x <- c(rgamma(50, 1, 2), rgamma(50, 2, 2), rgamma(50, 3, 2))
fctr <- c(rep(1, 50), rep(2, 50), rep(3, 50))
fctr <- factor(fctr, levels = c("1", "2", "3"))
gamma_shape_one_way(x, fctr, .95)