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diff --git a/docs/lod.html b/docs/lod.html deleted file mode 100644 index e5eb135..0000000 --- a/docs/lod.html +++ /dev/null @@ -1,199 +0,0 @@ -<!DOCTYPE html> -<html lang="en"> - <head> - <meta charset="utf-8"> -<title>lod. chemCal 0.1-37</title> -<meta name="viewport" content="width=device-width, initial-scale=1.0"> -<meta name="author" content=""> - -<link href="css/bootstrap.css" rel="stylesheet"> -<link href="css/bootstrap-responsive.css" rel="stylesheet"> -<link href="css/highlight.css" rel="stylesheet"> -<link href="css/staticdocs.css" rel="stylesheet"> - -<!--[if lt IE 9]> - <script src="http://html5shim.googlecode.com/svn/trunk/html5.js"></script> -<![endif]--> - -<script type="text/x-mathjax-config"> - MathJax.Hub.Config({ - tex2jax: { - inlineMath: [ ['$','$'], ["\\(","\\)"] ], - processEscapes: true - } - }); -</script> -<script type="text/javascript" - src="http://cdn.mathjax.org/mathjax/latest/MathJax.js?config=TeX-AMS-MML_HTMLorMML"> -</script> - </head> - - <body> - <div class="navbar"> - <div class="navbar-inner"> - <div class="container"> - <a class="brand" href="index.html">chemCal 0.1-37</a> - <div class="nav"> - <ul class="nav"> - <li><a href="index.html">Home</a></li> - <li><a href="reference.html">Reference</a></li> - </ul> - </div> - </div> - </div> -</div> - - - <div class="container"> - <header> - - </header> - - <h1>Estimate a limit of detection (LOD)</h1> - -<div class="row"> - <div class="span8"> - <h2>Usage</h2> - <pre><span class="functioncall"><a href='lod.html'>lod</a></span><span class="keyword">(</span><span class="symbol">object</span><span class="keyword">,</span> <span class="symbol">...</span><span class="keyword">,</span> <span class="argument">alpha</span> <span class="argument">=</span> <span class="number">0.05</span><span class="keyword">,</span> <span class="argument">beta</span> <span class="argument">=</span> <span class="number">0.05</span><span class="keyword">,</span> <span class="argument">method</span> <span class="argument">=</span> <span class="string">"default"</span><span class="keyword">,</span> <span class="argument">tol</span> <span class="argument">=</span> <span class="string">"default"</span><span class="keyword">)</span></pre> - - <h2>Arguments</h2> - <dl> - <dt>object</dt> - <dd> - A univariate model object of class <code><a href='http://www.rdocumentation.org/packages/stats/topics/lm'>lm</a></code> or - <code><a href='http://www.rdocumentation.org/packages/MASS/topics/rlm'>rlm</a></code> - with model formula <code>y ~ x</code> or <code>y ~ x - 1</code>, - optionally from a weighted regression. - </dd> - <dt>...</dt> - <dd> - Placeholder for further arguments that might be needed by - future implementations. - </dd> - <dt>alpha</dt> - <dd> - The error tolerance for the decision limit (critical value). - </dd> - <dt>beta</dt> - <dd> - The error tolerance beta for the detection limit. - </dd> - <dt>method</dt> - <dd> - The “default” method uses a prediction interval at the LOD - for the estimation of the LOD, which obviously requires - iteration. This is described for example in Massart, p. 432 ff. - The “din” method uses the prediction interval at - x = 0 as an approximation. - </dd> - <dt>tol</dt> - <dd> - When the “default” method is used, the default tolerance - for the LOD on the x scale is the value of the smallest non-zero standard - divided by 1000. Can be set to a numeric value to override this. - </dd> - </dl> - - <div class="Value"> - <h2>Value</h2> - - <p><dl> - A list containig the corresponding x and y values of the estimated limit of - detection of a model used for calibration. -</dl></p> - - </div> - - <div class="Description"> - <h2>Description</h2> - - <p>The decision limit (German: Nachweisgrenze) is defined as the signal or - analyte concentration that is significantly different from the blank signal - with a first order error alpha (one-sided significance test). - The detection limit, or more precise, the minimum detectable value - (German: Erfassungsgrenze), is then defined as the signal or analyte - concentration where the probability that the signal is not detected although - the analyte is present (type II or false negative error), is beta (also a - one-sided significance test).</p> - - </div> - - <div class="Note"> - <h2>Note</h2> - - <p>- The default values for alpha and beta are the ones recommended by IUPAC. - - The estimation of the LOD in terms of the analyte amount/concentration - xD from the LOD in the signal domain SD is done by simply inverting the - calibration function (i.e. assuming a known calibration function). - - The calculation of a LOD from weighted calibration models requires - a weights argument for the internally used <code><a href='http://www.rdocumentation.org/packages/stats/topics/predict.lm'>predict.lm</a></code> - function, which is currently not supported in R.</p> - - </div> - - <div class="References"> - <h2>References</h2> - - <p>Massart, L.M, Vandenginste, B.G.M., Buydens, L.M.C., De Jong, S., Lewi, P.J., - Smeyers-Verbeke, J. (1997) Handbook of Chemometrics and Qualimetrics: Part A, - Chapter 13.7.8</p> - - <p>J. Inczedy, T. Lengyel, and A.M. Ure (2002) International Union of Pure and - Applied Chemistry Compendium of Analytical Nomenclature: Definitive Rules. - Web edition.</p> - - <p>Currie, L. A. (1997) Nomenclature in evaluation of analytical methods including - detection and quantification capabilities (IUPAC Recommendations 1995). - Analytica Chimica Acta 391, 105 - 126.</p> - - </div> - - <h2 id="examples">Examples</h2> - <pre class="examples"><div class='input'><span class="functioncall"><a href='http://www.rdocumentation.org/packages/utils/topics/data'>data</a></span><span class="keyword">(</span><span class="symbol">din32645</span><span class="keyword">)</span> -<span class="symbol">m</span> <span class="assignement"><-</span> <span class="functioncall"><a href='http://www.rdocumentation.org/packages/stats/topics/lm'>lm</a></span><span class="keyword">(</span><span class="symbol">y</span> <span class="keyword">~</span> <span class="symbol">x</span><span class="keyword">,</span> <span class="argument">data</span> <span class="argument">=</span> <span class="symbol">din32645</span><span class="keyword">)</span> -<span class="functioncall"><a href='lod.html'>lod</a></span><span class="keyword">(</span><span class="symbol">m</span><span class="keyword">)</span></div> -<div class='output'>$x -[1] 0.08655484 - -$y - 1 -3317.154 - -</div> -<div class='input'> -<span class="comment"># The critical value (decision limit, German Nachweisgrenze) can be obtained</span> -<span class="comment"># by using beta = 0.5:</span> -<span class="functioncall"><a href='lod.html'>lod</a></span><span class="keyword">(</span><span class="symbol">m</span><span class="keyword">,</span> <span class="argument">alpha</span> <span class="argument">=</span> <span class="number">0.01</span><span class="keyword">,</span> <span class="argument">beta</span> <span class="argument">=</span> <span class="number">0.5</span><span class="keyword">)</span></div> -<div class='output'>$x -[1] 0.0698127 - -$y - 1 -3155.393 - -</div></pre> - </div> - <div class="span4 sidebar"> - <!-- <ul> - <li>lod</li><li>lod.lm</li><li>lod.rlm</li><li>lod.default</li> - </ul> - <ul> - <li>manip</li> - </ul> --> - - <h2>See also</h2> - <p>Examples for <code><a href='din32645.html'>din32645</a></code></p> - - - - - </div> -</div> - - <footer> - <p class="pull-right"><a href="#">Back to top</a></p> -<p>Built by <a href="https://github.com/hadley/staticdocs">staticdocs</a>. Styled with <a href="https://getbootstrap.com/2.0.4/">bootstrap</a>.</p> - </footer> - </div> - </body> -</html>
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