Added test_that test

Author: damontoth

tests/testthat/test-pNextGenSize.R

@@ -10,3 +10,15 @@ test_that("pNextGenSize() with multiple transmitters matches brute-force dnbinom
 
   expect_equal(pngs, dnb, tolerance = sqrt(.Machine$double.eps))
 })
+
+test_that("pFinalSize() matches brute-force calculation", {
+  pfs <- pFinalSize(n=1, j=4, R=1.2, k=0.33)
+  
+  d <- dnbinom(0:3, mu=1.2, size=0.33)
+  dnb <- d[4] * d[1]^3 +
+    d[3] * d[2] * d[1]^2 * 2 +
+    d[2] * d[3] * d[1]^2 +
+    d[2]^3 * d[1]
+  
+  expect_equal(pfs, dnb, tolerance = sqrt(.Machine$double.eps))
+})