Add actual/twa calcs for FOMC, typo

2 files changed, 38 insertions, 2 deletions

diff --git a/R/FOMC_actual_twa.R b/R/FOMC_actual_twa.R
new file mode 100644
index 0000000..dc869b5
--- /dev/null
+++ b/R/FOMC_actual_twa.R
@@ -0,0 +1,36 @@
+# Copyright (C) 2018  Johannes Ranke
+# Contact: jranke@uni-bremen.de
+# This file is part of the R package pfm
+
+# This program 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/>
+
+#' Actual and maximum moving window time average concentrations for FOMC kinetics
+#'
+#' @param alpha Parameter of the FOMC model
+#' @param beta Parameter of the FOMC model
+#' @param times The output times, and window sizes for time weighted average concentrations
+#' @export
+#' @author Johannes Ranke
+#' @source FOCUS (2014) Generic Guidance for Estimating Persistence and Degradation
+#'   Kinetics from Environmental Fate Studies on Pesticides in EU Registration, Version 1.1,
+#'   18 December 2014, p. 251
+#' @examples
+#' FOMC_actual_twa(alpha = 1.0001, beta = 10)
+FOMC_actual_twa <- function(alpha = 1.0001, beta = 10, times = c(0, 1, 2, 4, 7, 14, 21, 28, 42, 50, 100))
+{
+  result <- data.frame(actual = 1 / (times/beta + 1)^alpha,
+                       twa = (beta / (times * (1 - alpha))) * (((times / beta) + 1)^(1 - alpha) - 1),
+                       row.names = times)
+  return(result)
+}
diff --git a/R/SFO_actual_twa.R b/R/SFO_actual_twa.R
index 7facb6a..0d2015b 100644
--- a/R/SFO_actual_twa.R
+++ b/R/SFO_actual_twa.R
@@ -1,4 +1,4 @@
-# Copyright (C) 2015  Johannes Ranke
+# Copyright (C) 2015,2018  Johannes Ranke
 # Contact: jranke@uni-bremen.de
 # This file is part of the R package pfm
 
@@ -22,7 +22,7 @@
 #' @export
 #' @author Johannes Ranke
 #' @source FOCUS (2014) Generic Guidance for Estimating Persistence and Degradation
-#'   Kinetics from Environmental Fate Studies on Pesticides in EU Registratin, Version 1.1, 
+#'   Kinetics from Environmental Fate Studies on Pesticides in EU Registration, Version 1.1, 
 #'   18 December 2014, p. 251
 #' @examples
 #' SFO_actual_twa(10)