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| <h1>Scenario Comparison View</h1> |
| <p dir="ltr">The <em>Scenario Comparison View</em> allows a user to compare two data sets |
| and to measure the time varying Root Mean Square (RMS) difference between the |
| aggregate epidemic data. <br> |
| The data may be real data or the results from one or more completed simulations. |
| The algorithm used to measure the RMS difference |
| <span style="font-family:Symbol">d</span><sub>a,b</sub>(t) between two scenarios |
| ‘a’ and ‘b’ <br> |
| at time t averaged over all locations (i) is:<p class="MsoNormal"> |
| <img border="0" src="img/comparsonEquation.jpg" width="597" height="149"> |
| |
| </p> |
| <p class="MsoNormal">Note that each location ‘<i>i</i>’ is weighted by the local |
| population P<sub>i</sub> so more populous locations contribute more to the |
| measurement. The method assumes the scenarios a,b each cover the same set of |
| location {i} which is true in this case. The RMS difference is evaluated only at |
| locations that have a non-zero rate of infection at some time t. If, for |
| example, a comparison is made of two scenarios involving the entire planet but |
| the epidemic in question is localized to a small region (e.g., the state of |
| Vermont), one only wants to compare the model to the reference over those |
| locations where the epidemic actually took place. Including locations with I = 0<font face="Symbol">"</font><font face="Times New Roman">t</font> |
| would |
| artificially reduce the estimated RMS error.</p> |
| <p class="MsoNormal">Finally we note that the comparison is made including only |
| the S and I states. The algorithm compares these two disease state variables to |
| allow for comparisons between different types of models. In a real epidemic |
| scenario, one may wish to evaluate (for example) SI, SIR and SEIR models for the |
| same infectious disease. Since the S and I states are common to all, measuring |
| the RMS difference in this way allows for comparison across different types of |
| models. In cases where only the infectious or perhaps change in infectious<span style="position: relative; top: 2.0pt"> |
| <font face="Symbol">D</font>I </span><!--[if gte mso 9]><![endif]-->is |
| known, RMS comparison may also be made based only on the I state.</p> |
| <p> <p>To use the Scenario Comparison view:<ol> |
| <li>Enter the <a href="../perspectives/analysis.html">Analysis Perspective</a></li> |
| <li>Click on the Scenario Comparison Tab</li> |
| <li>Use the Select Folder buttons to chose the folders containing the data |
| you wish to compare. The files should have the following |
| <a href="csvloggerview.html"> format.</a></li> |
| <li>Click Analyze</li> |
| <li>The time varying RMS difference will appear in the chart and the |
| integrated RMS difference will appear in the console at the bottom of the |
| view.</li> |
| </ol> |
| </p> |
| <p> </p> |
| <img border="0" src="img/ScenarioComparison.jpg" width="1000" height="800"><p>6. |
| In this (or in any STEM chart) view, to toggle between a Linear and Log scale |
| simply right click on the chart and specify you plot preferences in the dialog |
| that<br> |
| appears (see below).</p> |
| <p><img border="0" src="img/ScenarioComparisonB.jpg" width="1000" height="800"> |
| </p> |
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