Add likelihood ratio test and other methods, fixes

The likelihood ratio test method is lrtest, in addition,
methods for update and residuals were added.

1 files changed, 27 insertions, 0 deletions

diff --git a/tests/testthat/test_tests.R b/tests/testthat/test_tests.R
new file mode 100644
index 00000000..523edc4a
--- /dev/null
+++ b/tests/testthat/test_tests.R
@@ -0,0 +1,27 @@
+context("Hypothesis tests")
+
+test_that("The likelihood ratio test works", {
+
+  expect_error(lrtest(fit_tc_1, f_tc_2), "not been fitted to the same data")
+
+  res <- lrtest(fit_nw_1, fit_tc_1)
+  expect_equal(res[["2", "Pr(>Chisq)"]], 0.9999998)
+
+})
+
+test_that("We can conveniently fix parameters using 'fixed_parms'", {
+  f_k2_fixed <- mkinfit("DFOP", FOCUS_2006_C, fixed_parms = c(k2 = 0.05), quiet = TRUE)
+  expect_equivalent(f_k2_fixed$bparms.ode["k2"], 0.05)
+})
+
+test_that("Updating fitted models works", {
+  f_dfop_const <- mkinfit("DFOP", FOCUS_2006_C, quiet = TRUE)
+  f_dfop_tc <- update(f_dfop_const, error_model = "tc")
+
+  f_soil_1_nw <- update(f_soil_1_tc, error_model = "const")
+  f_soil_1_nw_A2 <- update(f_soil_1_nw, fixed_parms = c(k_A2 = 0))
+  test_nw_tc <- lrtest(f_soil_1_nw, f_soil_1_tc)
+  expect_equivalent(test_nw_tc[["2", "Pr(>Chisq)"]], 2.113e-6)
+  test_nw_A2 <- lrtest(f_soil_1_nw, f_soil_1_nw_A2)
+  expect_equivalent(test_nw_A2[["2", "Pr(>Chisq)"]], 0.9999468)
+})