aboutsummaryrefslogtreecommitdiff
path: root/R/tffm0.R
diff options
context:
space:
mode:
Diffstat (limited to 'R/tffm0.R')
-rw-r--r--R/tffm0.R51
1 files changed, 0 insertions, 51 deletions
diff --git a/R/tffm0.R b/R/tffm0.R
deleted file mode 100644
index 56283a5d..00000000
--- a/R/tffm0.R
+++ /dev/null
@@ -1,51 +0,0 @@
-#' Transform formation fractions as in the first published mkin version
-#'
-#' This transformation was used originally in mkin, in order to implement a
-#' constraint for the sum of formation fractions to be smaller than 1. It was
-#' later replaced by the [ilr] transformation because the ilr transformed
-#' fractions can assumed to follow normal distribution. As the ilr
-#' transformation is not available in [RxODE] and can therefore not be used in
-#' the nlmixr modelling language, the original transformation is currently used
-#' for translating mkin models with formation fractions to more than one target
-#' compartment for fitting with nlmixr in [nlmixr_model]. However, this
-#' implementation cannot be used there, as it is not accessible from RxODE.
-#'
-#' If the transformed formation fractions are restricted to the interval
-#' between 0 and 1, the sum of backtransformed values is restricted
-#' to this interval.
-#'
-#' @param ff Vector of untransformed formation fractions. The sum
-#' must be smaller or equal to one
-#' @param ff_trans Vector of transformed formation fractions that can be
-#' restricted to the interval from 0 to 1
-#' @return A vector of the transformed formation fractions
-#' @export
-#' @examples
-#' ff_example <- c(
-#' 0.10983681, 0.09035905, 0.08399383
-#' )
-#' ff_example_trans <- tffm0(ff_example)
-#' invtffm0(ff_example_trans)
-tffm0 <- function(ff) {
- n <- length(ff)
- res <- numeric(n)
- f_remaining <- 1
- for (i in 1:n) {
- res[i] <- ff[i]/f_remaining
- f_remaining <- f_remaining - ff[i]
- }
- return(res)
-}
-#' @rdname tffm0
-#' @export
-#' @return A vector of backtransformed formation fractions for natural use in degradation models
-invtffm0 <- function(ff_trans) {
- n <- length(ff_trans)
- res <- numeric(n)
- f_remaining <- 1
- for (i in 1:n) {
- res[i] <- ff_trans[i] * f_remaining
- f_remaining <- f_remaining - res[i]
- }
- return(res)
-}

Contact - Imprint