From 0818986e2d9a0e68d3d1de26ac381836e0cf5a6f Mon Sep 17 00:00:00 2001 From: Johannes Ranke Date: Wed, 18 Sep 2019 12:17:34 +0200 Subject: Add hockey stick formulas to maximum twa vignette --- vignettes/twa.Rmd | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) (limited to 'vignettes/twa.Rmd') diff --git a/vignettes/twa.Rmd b/vignettes/twa.Rmd index 93b2b372..92a0cd4b 100644 --- a/vignettes/twa.Rmd +++ b/vignettes/twa.Rmd @@ -36,6 +36,12 @@ $$c_\textrm{twa} = \frac{c_0}{t} \left( \frac{g}{k_1} \left( 1 - e^{- k_1 t} \right) + \frac{1-g}{k_2} \left( 1 - e^{- k_2 t} \right) \right) $$ +HS for $t > t_b$: + +$$c_\textrm{twa} = \frac{c_0}{t} \left( + \frac{1}{k_1} \left( 1 - e^{- k_1 t_b} \right) + + \frac{e^{- k_1 t_b}}{k_2} \left( 1 - e^{- k_2 (t - t_b)} \right) \right) $$ + Often, the ratio between the time weighted average concentration $c_\textrm{twa}$ and the initial concentration $c_0$ @@ -60,8 +66,13 @@ $$f_\textrm{twa} = \frac{1}{t} \left( \frac{g}{k_1} \left( 1 - e^{- k_1 t} \right) + \frac{1-g}{k_2} \left( 1 - e^{- k_2 t} \right) \right) $$ +HS for $t > t_b$: + +$$f_\textrm{twa} = \frac{1}{t} \left( + \frac{1}{k_1} \left( 1 - e^{- k_1 t_b} \right) + + \frac{e^{- k_1 t_b}}{k_2} \left( 1 - e^{- k_2 (t - t_b)} \right) \right) $$ + Note that a method for calculating maximum moving window time weighted average concentrations for any model fitted by 'mkinfit', and also for metabolites in -such models, can be found in the 'pfm' package, which is currently not published on -CRAN, but available from [github](https://github.com/jranke/pfm) and -[documented](https://pkgdown.jrwb.de/pfm) at my website. +such models, is integrated in the 'mkin' package, see the +[documentation](https://pkgdown.jrwb.de/pfm/reference/max_twa_parent.html) at my website. -- cgit v1.2.1