From ec2052d68950745380c2724757b3ba8b116605fc Mon Sep 17 00:00:00 2001 From: Johannes Ranke Date: Fri, 8 Jun 2018 14:54:40 +0200 Subject: Add actual/twa calcs for FOMC, typo --- R/FOMC_actual_twa.R | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) create mode 100644 R/FOMC_actual_twa.R (limited to 'R/FOMC_actual_twa.R') 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 + +#' 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) +} -- cgit v1.2.1