1 files changed, 45 insertions, 0 deletions
diff --git a/tests/testthat/test_twa.R b/tests/testthat/test_twa.R
new file mode 100644
index 00000000..3a28e0c1
--- /dev/null
+++ b/tests/testthat/test_twa.R
@@ -0,0 +1,45 @@
+# Copyright (C) 2016 Johannes Ranke
+# Contact: jranke@uni-bremen.de
+
+# This file is part of the R package mkin
+
+# mkin is free software: you can redistribute it and/or modify it under the
+# terms of the GNU General Public License as published by the Free Software
+# Foundation, either version 3 of the License, or (at your option) any later
+# version.
+
+# This program is distributed in the hope that it will be useful, but WITHOUT
+# ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+# FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
+# details.
+
+# You should have received a copy of the GNU General Public License along with
+# this program. If not, see <http://www.gnu.org/licenses/>
+
+context("Calculation of maximum time weighted average concentrations (TWAs)")
+
+twa_models <- c("SFO", "FOMC", "DFOP")
+fits <- mmkin(twa_models, list(FOCUS_D = FOCUS_2006_D), 
+              quiet = TRUE)
+
+SFO_SFO <- mkinmod(parent = list(type = "SFO", to = "m1"),
+                   m1 = list(type = "SFO"), quiet = TRUE)
+fit.m1 <- mkinfit(SFO_SFO, FOCUS_2006_D, quiet = TRUE)
+
+test_that("Time weighted average concentrations are correct", {
+  outtimes_7 <- seq(0, 7, length.out = 10000)
+  for (model in twa_models) {
+    fit <- fits[[model, 1]]
+    bpar <- summary(fit)$bpar[, "Estimate"]
+    pred_7 <- mkinpredict(fit$mkinmod,
+                odeparms = bpar[2:length(bpar)],
+                odeini = c(parent = bpar[[1]]),
+                outtimes = outtimes_7)
+    twa_num <- mean(pred_7$parent)
+    names(twa_num) <- 7
+    twa_ana <- twa(fit, 7)
+
+    # Test for absolute difference (scale = 1)
+    expect_equal(twa_num, twa_ana, tolerance = 0.001, scale = 1)
+  }
+})