tests/testthat/test_01_ST4.R

In Stan125/gamlss.dist: Distributions for Generalized Additive Models for Location Scale and Shape

#########################################
#######     gamlss.dist        ##########
#######   Distribution tests 2 ##########
##### Skew Student t type 4: ST4() ######
#########################################

## Context
testthat::context("ST4 2")

## Seed
set.seed(241)

## Family
fam <- ST4()

## Random Values
i <- 1
n <- 1e6
mu <- 0 + i
sigma <- 1 + i
nu <- 10 + i
tau <- 10 + i
rvec <- rST4(n, mu, sigma, nu, tau)  

## Empirical Moments
ex_emp <- mean(rvec)
vx_emp <- var(rvec)

## Theoretical moments
ex_theo <- fam$mean(mu, sigma, nu, tau) 
vx_theo <- fam$variance(mu, sigma, nu, tau)

## Test here if they are about the same
expect_true(abs(ex_emp - ex_theo) < 0.02)  
expect_true(abs(vx_emp - vx_theo) < 0.02)