LRTesteR (version 1.2.1)

inverse_gaussian_shape_one_way: Test the equality of shape parameters of inverse gaussian distributions.

Description

Test the equality of shape parameters of inverse gaussian distributions.

Usage

inverse_gaussian_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 at least 50 data values per group.

fctr

a factor vector indicating groups.

conf.level

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

Details

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

• Alternative: At least one shape is not equal.

Examples

library(LRTesteR)
library(statmod)

# Null is true
set.seed(1)
x <- rinvgauss(n = 150, mean = 1, shape = 2)
fctr <- c(rep(1, 50), rep(2, 50), rep(3, 50))
fctr <- factor(fctr, levels = c("1", "2", "3"))
inverse_gaussian_shape_one_way(x, fctr, .95)

# Null is false
set.seed(1)
x <- c(
  rinvgauss(n = 50, mean = 1, shape = 1),
  rinvgauss(n = 50, mean = 1, shape = 3),
  rinvgauss(n = 50, mean = 1, shape = 4)
)
fctr <- c(rep(1, 50), rep(2, 50), rep(3, 50))
fctr <- factor(fctr, levels = c("1", "2", "3"))
inverse_gaussian_shape_one_way(x, fctr, .95)