<!DOCTYPE html> <!-- Generated by pkgdown: do not edit by hand --><html lang="en"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8"><meta charset="utf-8"><meta http-equiv="X-UA-Compatible" content="IE=edge"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Transform formation fractions as in the first published mkin version — tffm0 • mkin</title><!-- jquery --><script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.4.1/jquery.min.js" integrity="sha256-CSXorXvZcTkaix6Yvo6HppcZGetbYMGWSFlBw8HfCJo=" crossorigin="anonymous"></script><!-- Bootstrap --><link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.4.1/css/bootstrap.min.css" integrity="sha256-bZLfwXAP04zRMK2BjiO8iu9pf4FbLqX6zitd+tIvLhE=" crossorigin="anonymous"><script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.4.1/js/bootstrap.min.js" integrity="sha256-nuL8/2cJ5NDSSwnKD8VqreErSWHtnEP9E7AySL+1ev4=" crossorigin="anonymous"></script><!-- bootstrap-toc --><link rel="stylesheet" href="../bootstrap-toc.css"><script src="../bootstrap-toc.js"></script><!-- Font Awesome icons --><link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.12.1/css/all.min.css" integrity="sha256-mmgLkCYLUQbXn0B1SRqzHar6dCnv9oZFPEC1g1cwlkk=" crossorigin="anonymous"><link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/5.12.1/css/v4-shims.min.css" integrity="sha256-wZjR52fzng1pJHwx4aV2AO3yyTOXrcDW7jBpJtTwVxw=" crossorigin="anonymous"><!-- clipboard.js --><script src="https://cdnjs.cloudflare.com/ajax/libs/clipboard.js/2.0.6/clipboard.min.js" integrity="sha256-inc5kl9MA1hkeYUt+EC3BhlIgyp/2jDIyBLS6k3UxPI=" crossorigin="anonymous"></script><!-- headroom.js --><script src="https://cdnjs.cloudflare.com/ajax/libs/headroom/0.11.0/headroom.min.js" integrity="sha256-AsUX4SJE1+yuDu5+mAVzJbuYNPHj/WroHuZ8Ir/CkE0=" crossorigin="anonymous"></script><script src="https://cdnjs.cloudflare.com/ajax/libs/headroom/0.11.0/jQuery.headroom.min.js" integrity="sha256-ZX/yNShbjqsohH1k95liqY9Gd8uOiE1S4vZc+9KQ1K4=" crossorigin="anonymous"></script><!-- pkgdown --><link href="../pkgdown.css" rel="stylesheet"><script src="../pkgdown.js"></script><meta property="og:title" content="Transform formation fractions as in the first published mkin version — tffm0"><meta property="og:description" content="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."><!-- mathjax --><script src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.5/MathJax.js" integrity="sha256-nvJJv9wWKEm88qvoQl9ekL2J+k/RWIsaSScxxlsrv8k=" crossorigin="anonymous"></script><script src="https://cdnjs.cloudflare.com/ajax/libs/mathjax/2.7.5/config/TeX-AMS-MML_HTMLorMML.js" integrity="sha256-84DKXVJXs0/F8OTMzX4UR909+jtl4G7SPypPavF+GfA=" crossorigin="anonymous"></script><!--[if lt IE 9]> <script src="https://oss.maxcdn.com/html5shiv/3.7.3/html5shiv.min.js"></script> <script src="https://oss.maxcdn.com/respond/1.4.2/respond.min.js"></script> <![endif]--></head><body data-spy="scroll" data-target="#toc"> <div class="container template-reference-topic"> <header><div class="navbar navbar-default navbar-fixed-top" role="navigation"> <div class="container"> <div class="navbar-header"> <button type="button" class="navbar-toggle collapsed" data-toggle="collapse" data-target="#navbar" aria-expanded="false"> <span class="sr-only">Toggle navigation</span> <span class="icon-bar"></span> <span class="icon-bar"></span> <span class="icon-bar"></span> </button> <span class="navbar-brand"> <a class="navbar-link" href="../index.html">mkin</a> <span class="version label label-default" data-toggle="tooltip" data-placement="bottom" title="Released version">1.1.0</span> </span> </div> <div id="navbar" class="navbar-collapse collapse"> <ul class="nav navbar-nav"><li> <a href="../reference/index.html">Functions and data</a> </li> <li class="dropdown"> <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button" aria-expanded="false"> Articles <span class="caret"></span> </a> <ul class="dropdown-menu" role="menu"><li> <a href="../articles/mkin.html">Introduction to mkin</a> </li> <li> <a href="../articles/FOCUS_D.html">Example evaluation of FOCUS Example Dataset D</a> </li> <li> <a href="../articles/FOCUS_L.html">Example evaluation of FOCUS Laboratory Data L1 to L3</a> </li> <li> <a href="../articles/web_only/dimethenamid_2018.html">Example evaluations of dimethenamid data from 2018 with nonlinear mixed-effects models</a> </li> <li> <a href="../articles/web_only/FOCUS_Z.html">Example evaluation of FOCUS Example Dataset Z</a> </li> <li> <a href="../articles/web_only/compiled_models.html">Performance benefit by using compiled model definitions in mkin</a> </li> <li> <a href="../articles/twa.html">Calculation of time weighted average concentrations with mkin</a> </li> <li> <a href="../articles/web_only/NAFTA_examples.html">Example evaluation of NAFTA SOP Attachment examples</a> </li> <li> <a href="../articles/web_only/benchmarks.html">Some benchmark timings</a> </li> </ul></li> <li> <a href="../news/index.html">News</a> </li> </ul><ul class="nav navbar-nav navbar-right"><li> <a href="https://github.com/jranke/mkin/" class="external-link"> <span class="fab fa-github fa-lg"></span> </a> </li> </ul></div><!--/.nav-collapse --> </div><!--/.container --> </div><!--/.navbar --> </header><div class="row"> <div class="col-md-9 contents"> <div class="page-header"> <h1>Transform formation fractions as in the first published mkin version</h1> <small class="dont-index">Source: <a href="https://github.com/jranke/mkin/blob/HEAD/R/tffm0.R" class="external-link"><code>R/tffm0.R</code></a></small> <div class="hidden name"><code>tffm0.Rd</code></div> </div> <div class="ref-description"> <p>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 <a href="ilr.html">ilr</a> transformation because the ilr transformed fractions can assumed to follow normal distribution. As the ilr transformation is not available in <a href="https://nlmixrdevelopment.github.io/RxODE/reference/RxODE.html" class="external-link">RxODE</a> 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 <a href="nlmixr.mmkin.html">nlmixr_model</a>. However, this implementation cannot be used there, as it is not accessible from RxODE.</p> </div> <div id="ref-usage"> <div class="sourceCode"><pre class="sourceCode r"><code><span class="fu">tffm0</span><span class="op">(</span><span class="va">ff</span><span class="op">)</span> <span class="fu">invtffm0</span><span class="op">(</span><span class="va">ff_trans</span><span class="op">)</span></code></pre></div> </div> <div id="arguments"> <h2>Arguments</h2> <dl><dt>ff</dt> <dd><p>Vector of untransformed formation fractions. The sum must be smaller or equal to one</p></dd> <dt>ff_trans</dt> <dd><p>Vector of transformed formation fractions that can be restricted to the interval from 0 to 1</p></dd> </dl></div> <div id="value"> <h2>Value</h2> <p>A vector of the transformed formation fractions A vector of backtransformed formation fractions for natural use in degradation models</p> </div> <div id="details"> <h2>Details</h2> <p>If the transformed formation fractions are restricted to the interval between 0 and 1, the sum of backtransformed values is restricted to this interval.</p> </div> <div id="ref-examples"> <h2>Examples</h2> <div class="sourceCode"><pre class="sourceCode r"><code><span class="r-in"><span class="va">ff_example</span> <span class="op"><-</span> <span class="fu"><a href="https://rdrr.io/r/base/c.html" class="external-link">c</a></span><span class="op">(</span></span> <span class="r-in"> <span class="fl">0.10983681</span>, <span class="fl">0.09035905</span>, <span class="fl">0.08399383</span></span> <span class="r-in"><span class="op">)</span></span> <span class="r-in"><span class="va">ff_example_trans</span> <span class="op"><-</span> <span class="fu">tffm0</span><span class="op">(</span><span class="va">ff_example</span><span class="op">)</span></span> <span class="r-in"><span class="fu">invtffm0</span><span class="op">(</span><span class="va">ff_example_trans</span><span class="op">)</span></span> <span class="r-out co"><span class="r-pr">#></span> [1] 0.10983681 0.09035905 0.08399383</span> </code></pre></div> </div> </div> <div class="col-md-3 hidden-xs hidden-sm" id="pkgdown-sidebar"> <nav id="toc" data-toggle="toc" class="sticky-top"><h2 data-toc-skip>Contents</h2> </nav></div> </div> <footer><div class="copyright"> <p></p><p>Developed by Johannes Ranke.</p> </div> <div class="pkgdown"> <p></p><p>Site built with <a href="https://pkgdown.r-lib.org/" class="external-link">pkgdown</a> 2.0.2.</p> </div> </footer></div> </body></html>