From 0edd9ff5dcdc65de4f8438403fdee747335a6d5a Mon Sep 17 00:00:00 2001
From: PaulMelloy <paul@melloy.com.au>
Date: Tue, 30 Jul 2024 21:00:28 +1000
Subject: [PATCH] As per discussion in issue #22

---
 R/latent_period.R                       | 4 +++-
 tests/testthat/test-thermal_functions.R | 5 +++++
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/R/latent_period.R b/R/latent_period.R
index 5514974..a3f6fe6 100644
--- a/R/latent_period.R
+++ b/R/latent_period.R
@@ -1,7 +1,9 @@
 #' Calculate Cercospora latent period
 #'
 #' @details Calculates the latent period for *Cercospora beticola* infections on
-#' sugar beet
+#' sugar beet. Note the published formula in \insertCite{wolf_factors_2005}
+#' contains an error in the exponent. e(0.35 x (Tm - 10)) should be
+#' e(-0.35 x (Tm - 10)). See issue #22 on github for additional information.
 #'
 #' @param Tm numeric, Average temperature in degrees Celsius for a hour of the day
 #' @param ref character, method for calculating latent period. Default is `"wolf"`
diff --git a/tests/testthat/test-thermal_functions.R b/tests/testthat/test-thermal_functions.R
index 9ae2461..f677d8c 100644
--- a/tests/testthat/test-thermal_functions.R
+++ b/tests/testthat/test-thermal_functions.R
@@ -58,3 +58,8 @@ test_that("moisture_index(method =2) examples work", {
   expect_equal(moisture_index(55,rh_thresh = 50, method = 2), 0.00540259, tolerance = 0.00001)
 })
 
+# see issue #22
+plot(latent_period(9:35), x = 9:35,
+     xlab = "Temperature C",
+     ylab = "days",
+     pch = 16)