<!-- Generated by pkgdown: do not edit by hand --> <!DOCTYPE html> <html lang="en"> <head> <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>Calculated the log-likelihood of a fitted mkinfit object — logLik.mkinfit • mkin</title> <!-- jquery --> <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js" integrity="sha256-FgpCb/KJQlLNfOu91ta32o/NMZxltwRo8QtmkMRdAu8=" crossorigin="anonymous"></script> <!-- Bootstrap --> <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/css/bootstrap.min.css" integrity="sha256-916EbMg70RQy9LHiGkXzG8hSg9EdNy97GazNG/aiY1w=" crossorigin="anonymous" /> <script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.3.7/js/bootstrap.min.js" integrity="sha256-U5ZEeKfGNOja007MMD3YBI0A3OSZOQbeG6z2f2Y0hu8=" crossorigin="anonymous"></script> <!-- Font Awesome icons --> <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css" integrity="sha256-eZrrJcwDc/3uDhsdt61sL2oOBY362qM3lon1gyExkL0=" crossorigin="anonymous" /> <!-- clipboard.js --> <script src="https://cdnjs.cloudflare.com/ajax/libs/clipboard.js/2.0.4/clipboard.min.js" integrity="sha256-FiZwavyI2V6+EXO1U+xzLG3IKldpiTFf3153ea9zikQ=" crossorigin="anonymous"></script> <!-- sticky kit --> <script src="https://cdnjs.cloudflare.com/ajax/libs/sticky-kit/1.1.3/sticky-kit.min.js" integrity="sha256-c4Rlo1ZozqTPE2RLuvbusY3+SU1pQaJC0TjuhygMipw=" crossorigin="anonymous"></script> <!-- pkgdown --> <link href="../pkgdown.css" rel="stylesheet"> <script src="../pkgdown.js"></script> <meta property="og:title" content="Calculated the log-likelihood of a fitted mkinfit object — logLik.mkinfit" /> <meta property="og:description" content="This function simply calculates the product of the likelihood densities calculated using dnorm, i.e. assuming normal distribution. The total number of estimated parameters returned with the value of the likelihood is calculated as the sum of fitted degradation model parameters and the fitted error model parameters. For the case of unweighted least squares fitting, we calculate one constant standard deviation from the residuals using sd and add one to the number of fitted degradation model parameters. For the case of manual weighting, we use the weight given for each observation as standard deviation in calculating its likelihood and the total number of estimated parameters is equal to the number of fitted degradation model parameters. In the case of iterative reweighting, the variances obtained by this procedure are used in the likelihood calculations, and the number of estimated parameters is obtained by the number of degradation model parameters plus the number of variance model parameters, i.e. the number of observed variables if the reweighting method is "obs", and two if the reweighting method is "tc"." /> <meta name="twitter:card" content="summary" /> <!-- 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> 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<div class="row"> <div class="col-md-9 contents"> <div class="page-header"> <h1>Calculated the log-likelihood of a fitted mkinfit object</h1> <div class="hidden name"><code>logLik.mkinfit.Rd</code></div> </div> <div class="ref-description"> <p>This function simply calculates the product of the likelihood densities calculated using <code><a href='https://www.rdocumentation.org/packages/stats/topics/Normal'>dnorm</a></code>, i.e. assuming normal distribution.</p> <p>The total number of estimated parameters returned with the value of the likelihood is calculated as the sum of fitted degradation model parameters and the fitted error model parameters.</p> <p>For the case of unweighted least squares fitting, we calculate one constant standard deviation from the residuals using <code><a href='https://www.rdocumentation.org/packages/stats/topics/sd'>sd</a></code> and add one to the number of fitted degradation model parameters.</p> <p>For the case of manual weighting, we use the weight given for each observation as standard deviation in calculating its likelihood and the total number of estimated parameters is equal to the number of fitted degradation model parameters.</p> <p>In the case of iterative reweighting, the variances obtained by this procedure are used in the likelihood calculations, and the number of estimated parameters is obtained by the number of degradation model parameters plus the number of variance model parameters, i.e. the number of observed variables if the reweighting method is "obs", and two if the reweighting method is "tc".</p> </div> <pre class="usage"><span class='co'># S3 method for mkinfit</span> <span class='fu'><a href='https://www.rdocumentation.org/packages/stats/topics/logLik'>logLik</a></span>(<span class='no'>object</span>, <span class='no'>...</span>)</pre> <h2 class="hasAnchor" id="arguments"><a class="anchor" href="#arguments"></a>Arguments</h2> <table class="ref-arguments"> <colgroup><col class="name" /><col class="desc" /></colgroup> <tr> <th>object</th> <td><p>An object of class <code><a href='mkinfit.html'>mkinfit</a></code>.</p></td> </tr> <tr> <th>…</th> <td><p>For compatibility with the generic method</p></td> </tr> </table> <h2 class="hasAnchor" id="value"><a class="anchor" href="#value"></a>Value</h2> <p>An object of class <code><a href='https://www.rdocumentation.org/packages/stats/topics/logLik'>logLik</a></code> with the number of estimated parameters (degradation model parameters plus variance model parameters) as attribute.</p> <h2 class="hasAnchor" id="see-also"><a class="anchor" href="#see-also"></a>See also</h2> <div class='dont-index'><p>Compare the AIC of columns of <code><a href='mmkin.html'>mmkin</a></code> objects using <code><a href='AIC.mmkin.html'>AIC.mmkin</a></code>.</p></div> <h2 class="hasAnchor" id="examples"><a class="anchor" href="#examples"></a>Examples</h2> <pre class="examples"><div class='input'> </div><div class='input'> <span class='no'>sfo_sfo</span> <span class='kw'><-</span> <span class='fu'><a href='mkinmod.html'>mkinmod</a></span>( <span class='kw'>parent</span> <span class='kw'>=</span> <span class='fu'><a href='mkinsub.html'>mkinsub</a></span>(<span class='st'>"SFO"</span>, <span class='kw'>to</span> <span class='kw'>=</span> <span class='st'>"m1"</span>), <span class='kw'>m1</span> <span class='kw'>=</span> <span class='fu'><a href='mkinsub.html'>mkinsub</a></span>(<span class='st'>"SFO"</span>) )</div><div class='output co'>#> <span class='message'>Successfully compiled differential equation model from auto-generated C code.</span></div><div class='input'> <span class='no'>d_t</span> <span class='kw'><-</span> <span class='no'>FOCUS_2006_D</span> <span class='no'>d_t</span>[<span class='fl'>23</span>:<span class='fl'>24</span>, <span class='st'>"value"</span>] <span class='kw'><-</span> <span class='fu'><a href='https://www.rdocumentation.org/packages/base/topics/c'>c</a></span>(<span class='fl'>NA</span>, <span class='fl'>NA</span>) <span class='co'># can't cope with zero values at the moment</span> <span class='no'>f_nw</span> <span class='kw'><-</span> <span class='fu'><a href='mkinfit.html'>mkinfit</a></span>(<span class='no'>sfo_sfo</span>, <span class='no'>d_t</span>, <span class='kw'>quiet</span> <span class='kw'>=</span> <span class='fl'>TRUE</span>) <span class='co'># no weighting (weights are unity)</span> <span class='no'>f_obs</span> <span class='kw'><-</span> <span class='fu'><a href='mkinfit.html'>mkinfit</a></span>(<span class='no'>sfo_sfo</span>, <span class='no'>d_t</span>, <span class='kw'>reweight.method</span> <span class='kw'>=</span> <span class='st'>"obs"</span>, <span class='kw'>quiet</span> <span class='kw'>=</span> <span class='fl'>TRUE</span>) <span class='no'>f_tc</span> <span class='kw'><-</span> <span class='fu'><a href='mkinfit.html'>mkinfit</a></span>(<span class='no'>sfo_sfo</span>, <span class='no'>d_t</span>, <span class='kw'>reweight.method</span> <span class='kw'>=</span> <span class='st'>"tc"</span>, <span class='kw'>quiet</span> <span class='kw'>=</span> <span class='fl'>TRUE</span>) <span class='no'>d_t</span>$<span class='no'>err</span> <span class='kw'><-</span> <span class='no'>d_t</span>$<span class='no'>value</span> <span class='co'># Manual weighting assuming sigma ~ y</span> <span class='no'>f_man</span> <span class='kw'><-</span> <span class='fu'><a href='mkinfit.html'>mkinfit</a></span>(<span class='no'>sfo_sfo</span>, <span class='no'>d_t</span>, <span class='kw'>err</span> <span class='kw'>=</span> <span class='st'>"err"</span>, <span class='kw'>quiet</span> <span class='kw'>=</span> <span class='fl'>TRUE</span>) <span class='fu'><a href='https://www.rdocumentation.org/packages/stats/topics/AIC'>AIC</a></span>(<span class='no'>f_nw</span>, <span class='no'>f_obs</span>, <span class='no'>f_tc</span>, <span class='no'>f_man</span>)</div><div class='output co'>#> df AIC #> f_nw 5 204.4619 #> f_obs 6 205.8727 #> f_tc 6 143.8773 #> f_man 4 291.8000</div><div class='input'> </div></pre> </div> <div class="col-md-3 hidden-xs hidden-sm" id="sidebar"> <h2>Contents</h2> <ul class="nav nav-pills nav-stacked"> <li><a href="#arguments">Arguments</a></li> <li><a href="#value">Value</a></li> <li><a href="#see-also">See also</a></li> <li><a href="#examples">Examples</a></li> </ul> <h2>Author</h2> <p>Johannes Ranke</p> </div> </div> <footer> <div class="copyright"> <p>Developed by Johannes Ranke.</p> </div> <div class="pkgdown"> <p>Site built with <a href="https://pkgdown.r-lib.org/">pkgdown</a> 1.3.0.9000.</p> </div> </footer> </div> </body> </html>