Use roxygen for functions and methods

1 files changed, 36 insertions, 4 deletions

diff --git a/R/FOMC.solution.R b/R/FOMC.solution.R
index 8bd13d6b..f5e6a7ea 100644
--- a/R/FOMC.solution.R
+++ b/R/FOMC.solution.R
@@ -1,4 +1,36 @@
-FOMC.solution <- function(t, parent.0, alpha, beta)

-{

-	parent = parent.0 / (t/beta + 1)^alpha

-}

+#' First-Order Multi-Compartment kinetics
+#' 
+#' Function describing exponential decline from a defined starting value, with
+#' a decreasing rate constant.
+#' 
+#' The form given here differs slightly from the original reference by
+#' Gustafson and Holden (1990). The parameter \code{beta} corresponds to 1/beta
+#' in the original equation.
+#' 
+#' @param t Time.
+#' @param parent.0 Starting value for the response variable at time zero.
+#' @param alpha Shape parameter determined by coefficient of variation of rate
+#'   constant values.
+#' @param beta Location parameter.
+#' @return The value of the response variable at time \code{t}.
+#' @note The solution of the FOMC kinetic model reduces to the
+#'   \code{\link{SFO.solution}} for large values of \code{alpha} and
+#'   \code{beta} with \eqn{k = \frac{\beta}{\alpha}}{k = beta/alpha}.
+#' @references FOCUS (2006) \dQuote{Guidance Document on Estimating Persistence
+#'   and Degradation Kinetics from Environmental Fate Studies on Pesticides in
+#'   EU Registration} Report of the FOCUS Work Group on Degradation Kinetics,
+#'   EC Document Reference Sanco/10058/2005 version 2.0, 434 pp,
+#'   \url{http://esdac.jrc.ec.europa.eu/projects/degradation-kinetics}
+#' 
+#'   Gustafson DI and Holden LR (1990) Nonlinear pesticide dissipation in soil:
+#'   A new model based on spatial variability. \emph{Environmental Science and
+#'   Technology} \bold{24}, 1032-1038
+#' @examples
+#' 
+#'   plot(function(x) FOMC.solution(x, 100, 10, 2), 0, 2, ylim = c(0, 100))
+#' 
+#' @export
+FOMC.solution <- function(t, parent.0, alpha, beta)
+{
+	parent = parent.0 / (t/beta + 1)^alpha
+}