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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
&#8216;a&#8217; and &#8216;b&#8217; <br>
at time t averaged over all locations (i) is:<p class="MsoNormal">
<img border="0" src="img/comparsonEquation.jpg" width="597" height="149">
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;
</p>
<p class="MsoNormal">Note that each location &#8216;<i>i</i>&#8217; 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">&quot;</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>&nbsp;<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">&nbsp;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>&nbsp;</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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