diff options
author | Johannes Ranke <jranke@uni-bremen.de> | 2018-07-17 17:29:14 +0200 |
---|---|---|
committer | Johannes Ranke <jranke@uni-bremen.de> | 2018-07-17 17:38:29 +0200 |
commit | 280d36230052de4f94e384648c1283031fbc9840 (patch) | |
tree | df0ba9e07386b593cc396b8b6976210d42ee1a46 /docs/reference/massart97ex3.html | |
parent | e636c17f0d354a8e74546fc1469431dbe502dc76 (diff) |
Fix inverse predictions for replicate measurements
For details, see NEWS.md
Diffstat (limited to 'docs/reference/massart97ex3.html')
-rw-r--r-- | docs/reference/massart97ex3.html | 63 |
1 files changed, 36 insertions, 27 deletions
diff --git a/docs/reference/massart97ex3.html b/docs/reference/massart97ex3.html index 434fc7b..e9fa06a 100644 --- a/docs/reference/massart97ex3.html +++ b/docs/reference/massart97ex3.html @@ -61,17 +61,26 @@ </button> <span class="navbar-brand"> <a class="navbar-link" href="../index.html">chemCal</a> - <span class="label label-default" data-toggle="tooltip" data-placement="bottom" title="Released package">0.1.37.9001</span> + <span class="label label-default" data-toggle="tooltip" data-placement="bottom" title="Released package">0.2.1</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> + <a href="../index.html"> + <span class="fa fa-home fa-lg"></span> + + </a> </li> <li> - <a href="../articles/chemCal.pdf">Short manual (pdf)</a> + <a href="../articles/chemCal.html">Get started</a> +</li> +<li> + <a href="../reference/index.html">Reference</a> +</li> +<li> + <a href="../news/index.html">Changelog</a> </li> </ul> @@ -100,7 +109,7 @@ </div> - <pre class="usage"><span class='fu'>data</span>(<span class='no'>massart97ex3</span>)</pre> + <pre class="usage"><span class='no'>massart97ex3</span></pre> <h2 class="hasAnchor" id="format"><a class="anchor" href="#format"></a>Format</h2> @@ -115,18 +124,21 @@ <h2 class="hasAnchor" id="examples"><a class="anchor" href="#examples"></a>Examples</h2> - <pre class="examples"><div class='input'><span class='fu'>data</span>(<span class='no'>massart97ex3</span>) -<span class='fu'>attach</span>(<span class='no'>massart97ex3</span>)</div><div class='output co'>#> <span class='message'>The following objects are masked from massart97ex3 (pos = 3):</span> -#> <span class='message'></span> -#> <span class='message'> x, y</span></div><div class='input'><span class='no'>yx</span> <span class='kw'><-</span> <span class='fu'>split</span>(<span class='no'>y</span>, <span class='no'>x</span>) -<span class='no'>ybar</span> <span class='kw'><-</span> <span class='fu'>sapply</span>(<span class='no'>yx</span>, <span class='no'>mean</span>) -<span class='no'>s</span> <span class='kw'><-</span> <span class='fu'>round</span>(<span class='fu'>sapply</span>(<span class='no'>yx</span>, <span class='no'>sd</span>), <span class='kw'>digits</span> <span class='kw'>=</span> <span class='fl'>2</span>) -<span class='no'>w</span> <span class='kw'><-</span> <span class='fu'>round</span>(<span class='fl'>1</span> / (<span class='no'>s</span>^<span class='fl'>2</span>), <span class='kw'>digits</span> <span class='kw'>=</span> <span class='fl'>3</span>) -<span class='no'>weights</span> <span class='kw'><-</span> <span class='no'>w</span>[<span class='fu'>factor</span>(<span class='no'>x</span>)] -<span class='no'>m</span> <span class='kw'><-</span> <span class='fu'>lm</span>(<span class='no'>y</span> ~ <span class='no'>x</span>, <span class='kw'>w</span> <span class='kw'>=</span> <span class='no'>weights</span>) -<span class='fu'>calplot</span>(<span class='no'>m</span>)</div><div class='output co'>#> <span class='warning'>Warning: Assuming constant prediction variance even though model fit is weighted</span></div><div class='img'><img src='massart97ex3-1.png' alt='' width='700' height='433' /></div><div class='input'> + <pre class="examples"><div class='input'><span class='co'># For reproducing the results for replicate standard measurements in example 8,</span> +<span class='co'># we need to do the calibration on the means when using chemCal > 0.2</span> +<span class='no'>weights</span> <span class='kw'><-</span> <span class='fu'>with</span>(<span class='no'>massart97ex3</span>, { + <span class='no'>yx</span> <span class='kw'><-</span> <span class='fu'>split</span>(<span class='no'>y</span>, <span class='no'>x</span>) + <span class='no'>ybar</span> <span class='kw'><-</span> <span class='fu'>sapply</span>(<span class='no'>yx</span>, <span class='no'>mean</span>) + <span class='no'>s</span> <span class='kw'><-</span> <span class='fu'>round</span>(<span class='fu'>sapply</span>(<span class='no'>yx</span>, <span class='no'>sd</span>), <span class='kw'>digits</span> <span class='kw'>=</span> <span class='fl'>2</span>) + <span class='no'>w</span> <span class='kw'><-</span> <span class='fu'>round</span>(<span class='fl'>1</span> / (<span class='no'>s</span>^<span class='fl'>2</span>), <span class='kw'>digits</span> <span class='kw'>=</span> <span class='fl'>3</span>) +}) + +<span class='no'>massart97ex3.means</span> <span class='kw'><-</span> <span class='fu'>aggregate</span>(<span class='no'>y</span> ~ <span class='no'>x</span>, <span class='no'>massart97ex3</span>, <span class='no'>mean</span>) + +<span class='no'>m3.means</span> <span class='kw'><-</span> <span class='fu'>lm</span>(<span class='no'>y</span> ~ <span class='no'>x</span>, <span class='kw'>w</span> <span class='kw'>=</span> <span class='no'>weights</span>, <span class='kw'>data</span> <span class='kw'>=</span> <span class='no'>massart97ex3.means</span>) + <span class='co'># The following concords with the book p. 200</span> -<span class='fu'>inverse.predict</span>(<span class='no'>m</span>, <span class='fl'>15</span>, <span class='kw'>ws</span> <span class='kw'>=</span> <span class='fl'>1.67</span>) <span class='co'># 5.9 +- 2.5</span></div><div class='output co'>#> $Prediction +<span class='fu'><a href='inverse.predict.html'>inverse.predict</a></span>(<span class='no'>m3.means</span>, <span class='fl'>15</span>, <span class='kw'>ws</span> <span class='kw'>=</span> <span class='fl'>1.67</span>) <span class='co'># 5.9 +- 2.5</span></div><div class='output co'>#> $Prediction #> [1] 5.865367 #> #> $`Standard Error` @@ -137,7 +149,7 @@ #> #> $`Confidence Limits` #> [1] 3.387082 8.343652 -#> </div><div class='input'><span class='fu'>inverse.predict</span>(<span class='no'>m</span>, <span class='fl'>90</span>, <span class='kw'>ws</span> <span class='kw'>=</span> <span class='fl'>0.145</span>) <span class='co'># 44.1 +- 7.9</span></div><div class='output co'>#> $Prediction +#> </div><div class='input'><span class='fu'><a href='inverse.predict.html'>inverse.predict</a></span>(<span class='no'>m3.means</span>, <span class='fl'>90</span>, <span class='kw'>ws</span> <span class='kw'>=</span> <span class='fl'>0.145</span>) <span class='co'># 44.1 +- 7.9</span></div><div class='output co'>#> $Prediction #> [1] 44.06025 #> #> $`Standard Error` @@ -151,33 +163,30 @@ #> </div><div class='input'> <span class='co'># The LOD is only calculated for models from unweighted regression</span> <span class='co'># with this version of chemCal</span> -<span class='no'>m0</span> <span class='kw'><-</span> <span class='fu'>lm</span>(<span class='no'>y</span> ~ <span class='no'>x</span>) -<span class='fu'>lod</span>(<span class='no'>m0</span>)</div><div class='output co'>#> $x +<span class='no'>m0</span> <span class='kw'><-</span> <span class='fu'>lm</span>(<span class='no'>y</span> ~ <span class='no'>x</span>, <span class='kw'>data</span> <span class='kw'>=</span> <span class='no'>massart97ex3</span>) +<span class='fu'><a href='lod.html'>lod</a></span>(<span class='no'>m0</span>)</div><div class='output co'>#> $x #> [1] 5.407085 #> #> $y -#> 1 -#> 13.63911 +#> [1] 13.63911 #> </div><div class='input'> <span class='co'># Limit of quantification from unweighted regression</span> -<span class='fu'>loq</span>(<span class='no'>m0</span>)</div><div class='output co'>#> $x -#> [1] 13.97764 +<span class='fu'><a href='loq.html'>loq</a></span>(<span class='no'>m0</span>)</div><div class='output co'>#> $x +#> [1] 9.627349 #> #> $y -#> 1 -#> 30.6235 +#> [1] 22.00246 #> </div><div class='input'> <span class='co'># For calculating the limit of quantification from a model from weighted</span> <span class='co'># regression, we need to supply weights, internally used for inverse.predict</span> <span class='co'># If we are not using a variance function, we can use the weight from</span> <span class='co'># the above example as a first approximation (x = 15 is close to our</span> <span class='co'># loq approx 14 from above).</span> -<span class='fu'>loq</span>(<span class='no'>m</span>, <span class='kw'>w.loq</span> <span class='kw'>=</span> <span class='fl'>1.67</span>)</div><div class='output co'>#> $x +<span class='fu'><a href='loq.html'>loq</a></span>(<span class='no'>m3.means</span>, <span class='kw'>w.loq</span> <span class='kw'>=</span> <span class='fl'>1.67</span>)</div><div class='output co'>#> $x #> [1] 7.346195 #> #> $y -#> 1 -#> 17.90777 +#> [1] 17.90777 #> </div><div class='input'># The weight for the loq should therefore be derived at x = 7.3 instead # of 15, but the graphical procedure of Massart (p. 201) to derive the # variances on which the weights are based is quite inaccurate anyway. |