#context("binGP functions")

# We check the functions pbingp and qbingp.

# Set a tolerance for the comparison of the simulated values
my_tol <- 1e-5

# 1. Check that calling qgp with probabilities p and then calling pgp with
#    the results gets us back to the initial probabilities.

pqbingp_test_fn <- function(x, p) {
  p_u <- x[1]
  loc <- x[2]
  scale <- x[3]
  shape <- x[4]
  qs <- qbingp(p = p, p_u = p_u, loc = loc, scale = scale, shape = shape)
  ps <- pbingp(qs, p_u = p_u, loc = loc, scale = scale, shape = shape)
  return(list(p = p, ps = ps))
}

test_function <- function(x, test_string) {
  testthat::test_that(test_string, {
    testthat::expect_equal(x$p, x$ps, tolerance = my_tol)
  })
}

ep <- 1e-10
pu_check <- 0.4
loc_check <- 0
scale_check <- 2
shape_check <- c(-1, -0.5, -0.1, -ep, 0, ep, 0.1, 0.5, 1)
par_vals <- cbind(pu_check, loc_check, scale_check, shape_check)
p_vals <- 1 - pu_check + c(0.01, 0.1, 0.5, 0.9, 0.99) * pu_check
for (i in 1:nrow(par_vals)) {
  test_string <- paste("GP shape = ", par_vals[i, 4])
  x <- pqbingp_test_fn(x = par_vals[i, ], p = p_vals)
  test_function(x, test_string)
}